Mechanisms of Grain Growth Inhibition

The grain growth inhibitors primarily influence WC grain growth through the following approaches:

Solute Drag Effect

Principle:grain growth Inhibitor elements (e.g., V, Cr) dissolve into the WC or Co phase, adsorb at WC/Co phase boundaries or WC/WC grain boundaries, hindering atomic diffusion and grain boundary migration.

Elemental Solid Solution

Inhibitors such as VC and Cr?C? decompose during sintering, with V and Cr atoms dissolving into the WC lattice or Co binder phase.

Example: V substitutes W sites in WC (forming (V,W)C solid solution), while Cr dissolves into the Co phase (forming (Co,Cr) solid solution).

Grain Boundary Segregation

Solute atoms (e.g., V, Cr) enrich at WC grain boundaries or WC/Co interfaces, forming a “solute atmosphere.”

These segregated atoms pin grain boundaries, increasing the energy barrier for migration.

Drag on Grain Boundary Movement

When grain boundaries attempt to migrate, solute atoms must move along, but their slower diffusion rate impedes boundary motion.

Analogous to “viscous drag,” this suppresses WC grain coalescence and growth.

Applicable grain growth Inhibitors: VC, Cr?C? (primarily rely on solute drag).

Second-Phase Pinning Effect (Zener Pinning)

Principle: grain growth inhibitors form nanoscale carbide particles (e.g., (V,W)C, (Cr,W)C) that physically obstruct WC grain growth at boundaries.

Nanoparticle Precipitation

During sintering, decomposed VC or Cr?C? reprecipitate as nanoscale carbides (e.g., 5–50 nm (V,W)C particles), typically located at WC/WC or WC/Co interfaces.

Grain Boundary Pinning

Migrating boundaries must overcome the restraint of these nanoparticles, requiring additional energy.

According to the Zener equation, pinning force (F?) correlates with particle volume fraction (f) and size (r). Finer, denser particles yield stronger inhibition.

Suppression of WC Dissolution-Reprecipitation

Nanoparticles hinder WC dissolution in liquid Co and redeposition, reducing Ostwald ripening (“large grains consuming small ones”).

Applicable grain growth Inhibitors: VC (strongest pinning), Cr?C? (moderate), TaC/NbC (weaker).

Common Grain Growth Inhibitors and Their Characteristics

Selection and Optimization of grain growth Inhibitors

Ranking of Inhibition Effectiveness

VC > Cr?C? > TaC ≈ NbC

Key Influencing Factors

Sintering Temperature and Time:

High temperatures or prolonged sintering may weaken inhibitor effectiveness (e.g., VC particle coarsening).

Co Content

Alloys with higher Co require greater grain growth inhibitor content (due to enhanced WC dissolution in liquid Co).

Carbon Balance

Inhibitors may consume free carbon, necessitating carbon potential adjustment to avoid η-phase formation (e.g., Co?W?C).

Detailed Industrial Application Cases of Cemented 合金 Grain Growth Inhibitors

Grain growth inhibitors (e.g., VC, Cr?C?, TaC) are widely used in the cemented carbide industry, primarily in cutting tools, mining tools, and wear-resistant components. The selection of different inhibitors directly affects the alloy’s hardness, toughness, wear resistance, and high-temperature stability. Below is an in-depth analysis of several typical application cases.

Ultra-Fine Grain Cemented Carbide Cutting Tools (VC + Cr?C? Composite Inhibition)

Application Background

Requirement: High-speed cutting and precision machining (e.g., automotive engine blocks, aerospace titanium alloys) demand tools with both high hardness (>90 HRA) and chipping resistance.

Issue

Conventional WC-Co alloys have coarse grains (1–3 μm), exhibiting high hardness but low toughness, leading to edge chipping.

Solution

Ultra-fine grain cemented carbide (grain size 0.2–0.5 μm) achieved through VC (0.3–0.5 wt%) + Cr?C? (0.5–1.0 wt%) composite addition.

Inhibition Mechanism

VC: Nano-sized (V,W)C particles pin WC grain boundaries (Zener pinning), suppressing grain coalescence.

Cr?C?: Cr dissolves into the Co phase, reducing WC dissolution rate (solute drag) while enhancing oxidation resistance.

Representative Products

Sandvik GC4325: For titanium alloy machining, using VC+Cr?C? inhibition (0.3 μm grains).

Kennametal KCS10B: For stainless steel finishing, incorporating nano-VC.

Mining Cemented Carbide Drill Bits (TaC/NbC High-Temperature Inhibition)

Application Background

Requirement: Oil drill bits and tunnel boring machine cutters operate under high temperatures (>800°C) and impact loads, requiring thermal fatigue resistance and wear resistance.

Issue

Conventional WC-Co alloys experience rapid grain growth at high temperatures, reducing strength.

Solution

TaC (1–3 wt%) or NbC (1–2 wt%) addition to leverage their high-temperature stability for grain growth suppression.

Inhibition Mechanism

TaC/NbC: Form (Ta,W)C or (Nb,W)C solid solutions at high temperatures, pinning grain boundaries (Zener effect) and reducing boundary mobility.

Synergy with Co binder: Ta/Nb dissolution into Co increases liquid Co viscosity, slowing WC dissolution-reprecipitation.

Representative Products

Atlas Copco Button Bits: TaC-containing drill bits for granite drilling.

Sumitomo Electric DX Series: Oil drilling alloys with NbC for thermal stability.

Wear-Resistant Sealing Rings (Cr?C? Inhibition + Rare Earth Optimization)

Application Background

Requirement: Mechanical seals and bearing sleeves require high wear resistance + corrosion resistance (e.g., chemical pumps, seawater environments).

Issue

WC-Co suffers from selective corrosion of the Co phase in corrosive media, causing WC grain detachment.

Solution

Cr?C? (1.0–1.5 wt%) + rare earth oxides (Y?O? 0.1–0.3 wt%) composite addition.

Inhibition Mechanism:

Cr?C?: Forms (Cr,W)C particles to refine grains while improving corrosion resistance via Cr dissolution in Co.

Y?O?: Rare earth elements segregate at grain boundaries, purifying interfaces and strengthening boundary cohesion.

Representative Products

Mitsubishi Materials EX Series: Chemical pump seals with Cr?C? + rare earth modification.

Oerlikon Durit CR: Corrosion-resistant alloys with Cr?C?.

PCB Micro-Drills (Ultra-Fine VC + Sintering Process Optimization)

Application Background

Requirement: PCB micro-drills (diameter 0.1–0.3 mm) demand ultra-high precision (roundness <1 μm) and fatigue resistance.

Issue

Grain coarsening causes drill edge blunting and fracture during drilling.

Solution

Ultra-fine VC (0.2–0.4 wt%) + low-temperature sintering (1350°C, vs. conventional 1450°C).

Inhibition Mechanism

Nano-VC: Prepared via high-energy ball milling (<50 nm particles) for enhanced pinning.

Low-temperature sintering: Reduces Ostwald ripening time, preserving inhibitor efficacy.

Representative Products

Toshiba Tungaloy DLC-Coated Micro-Drills: Nano-VC inhibition technology.

TaeguTec PCB Drill: Optimized for high-layer PCBs.

結(jié)論

Grain growth inhibitors in cemented carbides control grain size through solute drag and second-phase pinning mechanisms. Their selection must be optimized based on material composition, sintering processes, and performance requirements. Future trends favor nano-composite inhibitors and multi-component synergistic regulation to further enhance comprehensive material properties.

At present, the regions in China that are most active in the recycling and regeneration of waste cemented carbide include Jinan City in Shandong Province, Qinghe County in Hebei Province, Mudanjiang City in Heilongjiang Province, and Zhuzhou City and Changsha City in Hunan Province.

Economic Benefits of Recycling Waste Carbide

Tungsten is the main component of cemented carbide, accounting for almost 50% of the total tungsten usage in its production, with China’s share being around 40%. Relevant data indicate that the demand for cemented carbide in various countries will rise significantly from the end of this century to the beginning of the next. It is estimated that by 2000, the demand could reach 40,000 tons, about 1.5 times the current production. However, tungsten is a rare element, with a crustal abundance of only 1×10?%, and the currently exploitable tungsten is only sufficient for 50 years.

Although China is a major producer of tungsten, both its reserves and recoverable quantities are showing a decreasing trend. Therefore, the rational utilization and recycling of tungsten resources should be placed on our agenda as an urgent issue to be seriously studied. Assuming that China’s recycling rate of waste alloy increases from 10% to 20%, it would mean an annual increase of several hundred tons of tungsten production. This would require the provision of several thousand tons of tungsten concentrate (containing 65% WO?) as raw material, equivalent to the tungsten content of 220,000 tons of raw ore (with a grade of 0.5% WO?). Thus, vigorously recycling cemented carbide is of great significance for the rational utilization and protection of existing tungsten resources.

Another major component of cemented carbide is cobalt. Due to the lack of cobalt resources in China, a large amount of cobalt needs to be imported annually to meet production needs. At the current level, recycling several hundred tons of cemented carbide in China each year could recover several tens of tons of cobalt, thereby saving a significant amount of foreign exchange for?our?country.

Processing Techniques of Recycling Waste Carbide

It is reported that there are currently about 30 different processing techniques used for the recycling of waste cemented carbide. Below is a brief introduction to several of the most commonly used and effective techniques in production.

Nitrate Fusion Method

This method involves melting waste cemented carbide together with nitrate at temperatures ranging from 900°C to 1200°C, resulting in the formation of soluble sodium tungstate. The reaction equation is as follows:

At this stage, the cooled melt is crushed and then leached with water to obtain a sodium tungstate solution and cobalt residue, which are then processed through normal procedures.

The advantages and disadvantages of this method are as follows: it has a large processing capacity and a wide range of applications, but it suffers from low recovery rates, high costs, poor working conditions, and significant pollution.

High-Temperature Oxidation Method

This method involves placing the cemented carbide in a temperature range of 700–950°C to oxidize it in air or oxygen. During this process, oxygen reacts with the alloy through the following chemical reaction:

The oxidized product is a brittle substance that, when treated with sodium hydroxide or a mixture of sodium hydroxide and sodium carbonate in a high-pressure leaching device, yields a sodium tungstate solution. The cobalt remaining in the residue is separated out according to conventional processes.

Phosphoric acid leaching method

Immerse the waste carbide?in a phosphoric acid solution and leach at a temperature of 50-60°C. Phosphoric acid reacts with cobalt in the carbide?to form cobalt phosphate, which enters the solution and separates from tungsten carbide. The advantages and disadvantages are: since phosphoric acid is a weak acid, the problem of equipment corrosion is easily solved, making it suitable for processing various waste carbides. However, the recovered tungsten carbide has a high oxygen content, and the subsequent process flow is long.

Zinc melting method

React waste carbides with zinc at a temperature close to 900°C. The cobalt in the alloy forms a zinc-cobalt low-melting-point alloy, causing the tungsten carbide in the waste alloy to lose the cobalt’s bonding effect and become loose. Then, vacuum distillation is used to evaporate and recover the metal zinc.

After the zinc melting process, the waste carbide?consists of layers of tungsten carbide and cobalt layers arranged in a multi-layered and interlocking pattern. It is a loose bulk material, which, after crushing, becomes a recycled carbide?mixture.

The advantages and disadvantages of the zinc melting method are: the process and equipment are relatively simple, the actual recovery rate is high, the production process causes less pollution, and the recovered mixture can be used directly for the production of tungsten products. However, this method consumes a lot of energy, with an electricity consumption of 4000-10000 degrees for processing 1 ton of waste carbide, and the recovered material contains a small amount of zinc, which has a certain impact on product quality.

Sodium sulfate fusion method

This method involves reacting waste carbides with sodium sulfate at a temperature of 900-1000°C to form a molten tungstic acid. After cooling, it is then leached with hot water to obtain a sodium tungstate solution and cobalt slag. The reaction equation is as follows: (The specific reaction equation is not provided in the original text, so it cannot be translated here.)

Its advantages and disadvantages are: wide adaptability and large production capacity. The drawback is that sulfur dioxide gas is emitted during the production process.

Electrolysis fusion method of recycling waste carbide

This method involves placing the waste carbide?in an electrolytic cell as the anode, nickel plate as the cathode, and dilute hydrochloric acid as the electrolyte. After electrolysis, the cobalt in the carbide?enters the solution in the form of COCl?. The washed and ground WC can be directly used to produce alloys. This method yields pure products, is highly efficient, has simple equipment, and is easy to operate. It is particularly suitable for processing with high cobalt content and has high value for promotion and application.

Cold embrittlement method

The cold embrittlement method involves crushing the waste carbide?coarsely, removing impurities, and then using a high-speed air stream to inject the coarsely crushed carbide?into a vacuum chamber equipped with a carbide?paddle, followed by further crushing to obtain a mixture.

This method has a wide range of processing and treatment, and the production process does not cause environmental pollution, but the equipment cost is relatively high.

According to reports, the zinc dissolution method is widely used for the recycling of waste carbides in China at the current stage. Overseas, the most economical method is considered to be a combination of the zinc dissolution method and the cold embrittlement method. In summary, there are many methods for recycling and processing waste carbides, each with its own pros and cons. When selecting a method in practice, a comprehensive analysis and comparison should be conducted based on the type of waste carbide, the size of the production scale, equipment capacity, technical level, and the source of raw and auxiliary materials, to choose an advanced, reasonable, and economically significant process for production practice.

Technical and Economic Preliminary Evaluation of Several Process Methods for Recycling Waste Carbides

As mentioned earlier, the zinc fusion method, electrolysis dissolution method, and mechanical crushing method have all become the main industrial methods for recycling and regenerating waste carbides. The recycled and regenerated powders can be used to produce carbides through conventional processes, which undoubtedly promotes the full utilization of non-ferrous metal resources such as tungsten and cobalt, saves energy, reduces manufacturing costs, promotes the development of small and medium-sized enterprises, and provides employment for the unemployed. Among them, the powder produced by the electrolysis dissolution method is particularly good in quality with low impurity content, low energy consumption, moderate processing costs, and good economic benefits (the selling price of WC powder is only 60% to 70% of the conventional product). It is one of the main methods being vigorously developed in many regions of our country.

摘要

It should be pointed out that the recycling and regeneration of waste carbides is a new venture and an emerging industrial sector in the field of carbides, which should be affirmed and supported. At the same time, great attention must be paid to product quality in the work of recycling and utilizing waste carbides, especially since most enterprises are still at a relatively low level of manual workshop production. Many enterprises often focus only on economic benefits while neglecting the control and testing of the recycling process and powder quality, which is incorrect. In the future, enterprises engaged in this kind of production should continuously improve and enhance the recycling process and product quality, strengthen the recognition of the importance of “product quality is the life of the enterprise,” and must not be careless. Otherwise, it will be difficult to maintain a firm foothold in the fierce market competition for a long time, let alone continue to develop and grow.

1.深冷處理工藝開發(fā)

Cryogenic treatment usually adopts liquid nitrogen cooling, which can cool the workpiece to below – 190 ℃. The microstructure of the treated material changes at low temperature, and some properties are improved. Cryogenic treatment was first proposed by the former Soviet Union in 1939. It was not until the 1960s that the United States applied the cryogenic treatment technology to the industry and began to use it mainly in the aviation field. In the 1970s, it expanded to the machinery manufacturing field.

根據(jù)冷卻方式不同，可分為液體法和氣體法。液態(tài)法是指將材料或工件直接浸入液氮中，將工件冷卻至液氮溫度，并將工件在該溫度下保持一定時(shí)間，然后取出加熱至一定溫度.這種方式很難控制升溫和降溫的速度，對(duì)工件的熱影響很大，一般認(rèn)為容易對(duì)工件造成損壞。低溫設(shè)備比較簡(jiǎn)單，比如液氮罐。

2.氣法深冷處理

The gas principle is to cool by the gasification latent heat of liquid nitrogen (about 199.54kJ/kg) and the heat absorption of low-temperature nitrogen. The gas method can make the cryogenic temperature reach – 190 ℃, so that the cryogenic nitrogen can contact the materials. Through convection heat exchange, the nitrogen can be vaporized in the cryogenic box after being ejected from the nozzle. The workpiece can be cooled by the latent heat of gasification and the heat absorption of cryogenic nitrogen. By controlling the input of liquid nitrogen to control the cooling rate, the cryogenic treatment temperature can be automatically adjusted and accurately controlled, and the thermal shock effect is small, so is the possibility of cracking.

目前，氣體法在其應(yīng)用中得到了研究人員的廣泛認(rèn)可，其冷卻設(shè)備主要是溫度可控的可編程低溫箱。深冷處理可顯著提高黑色金屬、有色金屬、金屬合金等材料的使用壽命、耐磨性和尺寸穩(wěn)定性，具有可觀的經(jīng)濟(jì)效益和市場(chǎng)前景。

硬質(zhì)合金的低溫技術(shù)在1980年代和1990年代首次被報(bào)道。 機(jī)械技術(shù) 日本在 1981 年和 現(xiàn)代機(jī)械車間 美國 1992 年報(bào)道，硬質(zhì)合金經(jīng)深冷處理后性能顯著提高。 1970年代以來，國外對(duì)低溫處理的研究工作卓有成效。前蘇聯(lián)、美國、日本等國家已成功地采用深冷處理，提高了工模具的使用壽命、工件的耐磨性和尺寸穩(wěn)定性。

3.深冷處理的強(qiáng)化機(jī)理

金屬相增強(qiáng)。

硬質(zhì)合金中的Co具有fcc晶體結(jié)構(gòu)α相（fcc）和密排六方晶體結(jié)構(gòu)ε相（hcp）。 ε-Co比α-Co摩擦系數(shù)小，耐磨性強(qiáng)。 417℃以上α相的自由能較低，所以存在Coα相形式。 417℃以下ε相的低自由能，高溫下穩(wěn)定相α相轉(zhuǎn)變?yōu)榈妥杂赡堞畔?。但由于WC顆粒和α相中固溶雜原子的存在對(duì)相變有較大的約束，使得α→ε當(dāng)相變阻力增大，溫度降至417℃以下時(shí)α相不能完全轉(zhuǎn)變進(jìn)入ε相。深冷處理可以大大增加α和ε兩相自由能差，從而增加ε相變的驅(qū)動(dòng)力變量。對(duì)于深冷處理后的硬質(zhì)合金，由于溶解度降低，部分溶解在Co中的原子以化合物的形式析出，可以增加Co基體中的硬質(zhì)相，阻礙位錯(cuò)運(yùn)動(dòng)，起到強(qiáng)化第二相的作用。粒子。

強(qiáng)化表面殘余應(yīng)力。

深冷處理后的研究表明，表面殘余壓應(yīng)力增加。許多研究人員認(rèn)為，使表層殘余壓應(yīng)力達(dá)到一定值，可以大大提高其使用壽命。在硬質(zhì)合金燒結(jié)后的冷卻過程中，結(jié)合相Co受到拉應(yīng)力，WC顆粒受到壓應(yīng)力。拉應(yīng)力對(duì)Co的破壞很大。因此，有研究人員認(rèn)為，深度冷卻引起的表面壓應(yīng)力增加減緩或部分抵消了燒結(jié)后冷卻過程中鍵合相產(chǎn)生的拉應(yīng)力，甚至將其調(diào)整為壓縮應(yīng)力，減少微裂紋的產(chǎn)生。

其他強(qiáng)化機(jī)制

認(rèn)為 η 相顆粒與 WC 顆粒一起使基體更加致密和堅(jiān)固，并且由于 η 相的形成消耗了基體中的 Co。結(jié)合相中Co含量的降低提高了材料的整體熱導(dǎo)率，碳化物粒徑和鄰接性的增加也提高了基體的熱導(dǎo)率。由于導(dǎo)熱系數(shù)的增加，工具和模具尖端的散熱更快；提高工模具的耐磨性和高溫硬度。也有人認(rèn)為，深冷處理后，由于 Co 的收縮和致密化，Co 對(duì) WC 顆粒的牢固作用得到加強(qiáng)。物理學(xué)家認(rèn)為，深度冷卻改變了金屬原子和分子的結(jié)構(gòu)。

4.YG20深冷冷鐓模一例

YG20冷墩模板深冷處理操作步驟：

(1)將燒結(jié)好的冷鐓模具放入深冷處理爐；

(2) Start the cryogenic tempering integrated furnace, open the liquid nitrogen, reduce it to – 60 ℃ at a certain rate, and keep the temperature for 1h;

(3) Reduce to – 120 ℃ at a certain rate, and keep the temperature for 2h;

(4) Reduce the temperature to – 190 ℃ at a certain cooling rate, and keep the temperature for 4-8h;

(5)保溫后按0.5℃/min升溫至180℃保溫4h

(6)程序設(shè)備完成后，自動(dòng)斷電，自然冷卻至室溫。

結(jié)論：未經(jīng)深冷處理和經(jīng)深冷處理的YG20冷鐓模具為冷鐓Φ3.8碳鋼螺桿，結(jié)果表明經(jīng)深冷處理后的模具使用壽命比未經(jīng)深冷處理的模具長15%以上.

可以看出，與深冷處理前相比，深冷處理后YG20中的面心立方鈷（fcc）明顯減少，ε-Co（hcp）的明顯增加也是耐磨性和硬質(zhì)合金的綜合性能。

5.深冷處理工藝的局限性

美國某工模具公司的實(shí)際應(yīng)用結(jié)果表明，硬質(zhì)合金刀片經(jīng)處理后使用壽命提高2~8倍，而硬質(zhì)合金拉絲模具經(jīng)處理后的修整周期由數(shù)周延長到幾個(gè)月。 1990年代，國內(nèi)開展了硬質(zhì)合金深冷技術(shù)研究，取得了一定的研究成果。

總的來說，目前對(duì)硬質(zhì)合金深冷處理技術(shù)的研究還不夠發(fā)達(dá)，不夠系統(tǒng)，得出的結(jié)論也不一致，需要研究人員進(jìn)一步深入探索。根據(jù)現(xiàn)有研究資料，深冷處理主要提高硬質(zhì)合金的耐磨性和使用壽命，但對(duì)物理性能沒有明顯影響。

Edge radius processing is an indispensable process after fine grinding of CNC tools and before coating. The purpose is to make the cutting edge smooth and smooth, and extend the tool life. There are 9 methods of edge radius treatment of CNC tools introduced by Meetyou. Let’s get to know it.

Edge radius?treatment of the cutting tools of the machining center refers to the process of leveling, polishing and deburring the cutting tools, including edge passivation, chip removal groove polishing and coating polishing.

1. Resistance to tool physical wear

In the cutting process, the tool surface will be gradually consumed by the workpiece, and the cutting edge is prone to plastic deformation under high temperature and high pressure. The passivation treatment of tools can help improve the rigidity of tools and avoid premature loss of cutting performance of tools.

2. Maintain the smoothness of the workpiece

Burrs on the cutting edge of the tool will cause tool wear, and the surface of the machined workpiece will become rough. After passivation treatment, the cutting edge of the tool will become very smooth, the phenomenon of edge collapse will be reduced accordingly, and the surface finish of the workpiece will also be improved.

3. Convenient groove chip removal

Polishing the tool groove can improve the surface quality and chip removal performance. The smoother the groove surface, the better chip removal will be, and more consistent cutting can be achieved.

After passivation and polishing, the tools of CNC machine tools will leave many small holes on the surface. These holes can absorb more cutting fluid during machining, which will greatly reduce the heat generated during cutting and greatly improve the cutting speed.

9 kinds of edge radius processing methods

Grinding wheel edge radius?method

This is the earliest and most widely used passivation technology.

Nylon brush?edge radius?method

it is a common method to coat the abrasive medium of fine particles on the brush wheel or brush disc of nylon material, and re move the cutter through the high-speed rotation of the brush.

Sand blasting method

it is divided into dry sand blasting and wet sand blasting. It is also a common method of edge radius processing. Compared with nylon brush method, this process accomplish?a higher consistency of edges.

Stirring method of edge radius processing

This method is to put the whole tool into the abrasive bucket before treatment, and position the depth of the tool through the laser sensor to ensure the quality of treatment. The blade consistency of this process is also higher than that of nylon brush method.

Electrochemical mechanical edge radius processing

This is a composite process that combines electrochemical machining and mechanical grinding. First, electrolytic deburring, and then mechanical grinding to remove oxide film.

Laser method: it is a passivation technology developed on the basis of laser cladding technology. It can produce high heat on the blade surface by laser, melt some materials, and achieve the effect of passivating the blade.

Vibration edge radius processing method

 the main processing device includes a vibration table and a worktable. The blade is placed in a container that is connected with the vibration body. The container is filled with abrasive particles. The abrasive particles and the blade repeatedly collide to remove trace materials on the cutting edge through collision to achieve edge passivation.

Magnetic abrasive method

This is a edge radius processing that applies a magnetic field in the direction perpendicular to the axis of the cylindrical surface of the workpiece, and adds magnetic abrasive between the magnetic field S and N poles. The magnetic abrasive will be adsorbed on the magnetic pole and the workpiece surface, and will be arranged into a flexible “abrasive brush” along the direction of the magnetic line of force. The cutter rotates and vibrates axially at the same time to remove the metal and burrs on the workpiece surface.

Micro abrasive water jet technology: a new and environment-friendly processing technology, which forms a liquid-solid high-energy jet through the control of the pressurizer and nozzle diameter, and realizes passivation treatment by high-speed and repeated collision on the workpiece.

蝕刻是一種利用化學(xué)強(qiáng)酸腐蝕、機(jī)械拋光或電化學(xué)電解對(duì)物體表面進(jìn)行處理的技術(shù)。除了增強(qiáng)美觀外，還增加了物品的附加值。從傳統(tǒng)的金屬加工到高科技半導(dǎo)體制造，都在蝕刻技術(shù)的應(yīng)用范圍之內(nèi)。

金屬蝕刻是一種通過化學(xué)反應(yīng)或物理沖擊去除金屬材料的技術(shù)。金屬蝕刻技術(shù)可分為濕法蝕刻和干法蝕刻。金屬蝕刻由一系列化學(xué)過程組成。不同的蝕刻劑對(duì)不同的金屬材料具有不同的腐蝕特性和強(qiáng)度。

金屬蝕刻又稱光化學(xué)蝕刻，是指在金屬蝕刻過程中，經(jīng)過曝光、制版、顯影以及與化學(xué)溶液接觸后，去除金屬蝕刻區(qū)域的保護(hù)膜，從而達(dá)到溶解腐蝕、形成的顛簸，或挖空。最早用于制造銅板、鋅板等印刷凹凸板。廣泛用于減輕儀表板重量或加工銘牌等薄型工件。通過技術(shù)和工藝設(shè)備的不斷改進(jìn)，蝕刻技術(shù)已應(yīng)用于航空、機(jī)械、化工和半導(dǎo)體制造工藝，用于電子薄件精密金屬蝕刻產(chǎn)品的加工。

蝕刻技術(shù)的種類

濕法蝕刻：

濕法刻蝕是將晶圓浸入合適的化學(xué)溶液中或?qū)⒒瘜W(xué)溶液噴到晶圓上進(jìn)行淬火，通過溶液與被蝕刻物體的化學(xué)反應(yīng)去除薄膜表面的原子，從而達(dá)到刻蝕的目的 濕法刻蝕時(shí)，溶液中的反應(yīng)物首先通過停滯的邊界層擴(kuò)散，然后到達(dá)晶片表面，通過化學(xué)反應(yīng)產(chǎn)生各種產(chǎn)物。蝕刻化學(xué)反應(yīng)的產(chǎn)物是液相或氣相產(chǎn)物，然后通過邊界層擴(kuò)散并溶解在主溶液中。濕法蝕刻不僅會(huì)在垂直方向進(jìn)行蝕刻，還會(huì)產(chǎn)生水平蝕刻的效果。

干法蝕刻：

干法蝕刻通常是等離子蝕刻或化學(xué)蝕刻中的一種。由于蝕刻效果不同，等離子體中離子的物理原子、活性自由基與器件（晶片）表面原子的化學(xué)反應(yīng)，或兩者的結(jié)合，包括以下內(nèi)容：

物理蝕刻：濺射蝕刻、離子束蝕刻

化學(xué)蝕刻：等離子蝕刻

物化復(fù)合蝕刻：反應(yīng)離子蝕刻（RIE）

干法刻蝕是各向異性刻蝕的一種，方向性好，但選擇性比濕法刻蝕差。在等離子刻蝕中，等離子是一種部分解離的氣體，氣體分子解離成電子、離子等具有高化學(xué)活性的物質(zhì)。干法蝕刻的最大優(yōu)點(diǎn)是“各向異性蝕刻”。但是，干法刻蝕的選擇性低于濕法刻蝕。這是因?yàn)楦煞涛g的刻蝕機(jī)理是物理相互作用；因此，離子的沖擊不僅可以去除蝕刻膜，還可以去除光刻膠掩模。

蝕刻工藝

根據(jù)金屬的種類，蝕刻工藝會(huì)有所不同，但一般蝕刻工藝如下：金屬蝕刻板→清洗除油→水洗→干燥→涂膜或絲印油墨→干燥→曝光繪圖→顯影→水洗烘干→蝕刻→脫膜→烘干→檢驗(yàn)→成品包裝。

1、金屬蝕刻前的清洗工藝：

蝕刻不銹鋼或其他金屬前的工序?yàn)榍逑刺幚?，主要用于去除材料表面的污垢、灰塵、油漬等。清洗工藝是保證后續(xù)薄膜或絲印油墨對(duì)金屬表面具有良好附著力的關(guān)鍵。因此，必須將金屬蝕刻表面的油污和氧化膜徹底清除。脫脂應(yīng)根據(jù)工件的油污情況而定。最好在電脫脂前對(duì)絲印油墨進(jìn)行脫脂，以保證脫脂效果。除氧化膜外，還應(yīng)根據(jù)金屬種類和膜厚選擇最佳蝕刻液，以保證表面清潔度。絲網(wǎng)印刷前必須干燥。如果有濕氣。

2、粘貼干膜或絲印感光膠層：

根據(jù)實(shí)際產(chǎn)品材質(zhì)、厚度和圖形的確切寬度，確定使用干膜或濕膜絲印。對(duì)于不同厚度的產(chǎn)品，在應(yīng)用感光層時(shí)應(yīng)考慮產(chǎn)品圖形所需的蝕刻加工時(shí)間等因素。它可以制作更厚或更薄的感光膠層，具有良好的覆蓋性能和高清晰度的金屬蝕刻圖案。

3、干燥：

薄膜或卷筒絲印油墨完成后，感光膠層需要徹底干燥，為曝光過程做準(zhǔn)備。同時(shí)，確保表面清潔，無粘連、雜質(zhì)等。

4、曝光：

此工序是金屬蝕刻的重要工序，曝光能量將根據(jù)產(chǎn)品材料的厚度和精度來考慮。這也是蝕刻企業(yè)技術(shù)能力的體現(xiàn)。曝光工藝決定了蝕刻能否保證更好的尺寸控制精度等要求。

5.發(fā)展：

金屬蝕刻板表面的感光膠層曝光后，圖案膠層曝光后固化。然后，圖案中不需要的部分，即需要腐蝕的部分，被暴露出來。開發(fā)過程也決定了產(chǎn)品的最終尺寸能否滿足要求。此過程將徹底去除產(chǎn)品上不必要的感光膠層。

6、蝕刻或蝕刻工藝：

產(chǎn)品預(yù)制過程完成后，化學(xué)溶液將被蝕刻。這個(gè)過程決定了最終產(chǎn)品是否合格。這個(gè)過程涉及蝕刻溶液的濃度、溫度、壓力、速度和其他參數(shù)。產(chǎn)品的質(zhì)量需要由這些參數(shù)來決定。

7. 拆除：

蝕刻后的產(chǎn)品表面還覆蓋著一層光敏膠，蝕刻后的產(chǎn)品表面的光敏膠層需要去除。由于感光膠層呈酸性，多采用酸堿中和法膨脹。溢流清洗和超聲波清洗后，去除表面的感光膠層，防止感光膠殘留。

8.測(cè)試：

取片后，接下來就是測(cè)試、包裝，最后確認(rèn)產(chǎn)品是否符合規(guī)格。

蝕刻過程中的注意事項(xiàng)

減少側(cè)蝕和凸邊，提高金屬蝕刻加工系數(shù)：一般印制板在金屬蝕刻液中的時(shí)間越長，側(cè)蝕越嚴(yán)重。咬邊嚴(yán)重影響印制線的精度，嚴(yán)重的咬邊不會(huì)使線變細(xì)。當(dāng)?shù)浊泻瓦吘墱p少時(shí)，蝕刻系數(shù)增加。高蝕刻系數(shù)表明細(xì)線可以保持，蝕刻線接近原始圖像的尺寸。抗鍍層無論是錫鉛合金、錫、錫鎳合金還是鎳，過度突出的邊緣都會(huì)導(dǎo)致導(dǎo)體短路。由于突出的邊緣容易折斷，因此在導(dǎo)體的兩點(diǎn)之間形成了電橋。

提高板間蝕刻加工速度的一致性：在連續(xù)板蝕刻中，金屬蝕刻加工速度越一致，可以獲得越均勻的蝕刻板。為了在預(yù)刻蝕過程中保持最佳的刻蝕狀態(tài)，需要選擇一種易于再生補(bǔ)償、易于控制刻蝕速率的刻蝕溶液。選擇能夠提供恒定運(yùn)行條件并自動(dòng)控制各種解決方案參數(shù)的技術(shù)和設(shè)備?？梢酝ㄟ^控制銅的溶解量、pH值、溶液濃度、溫度、溶液流量的均勻性等來實(shí)現(xiàn)。

提高整個(gè)板面金屬蝕刻加工速度的均勻性：板面上下兩面及板面各部分的蝕刻均勻性由金屬蝕刻液流速的均勻性決定板面。在蝕刻過程中，上下板的蝕刻速率往往不一致。下板表面的蝕刻速率高于上板表面的蝕刻速率。由于溶液在上板表面積聚，蝕刻反應(yīng)減弱。上下板的蝕刻不均勻可以通過調(diào)整上下噴嘴的注射壓力來解決。噴霧系統(tǒng)和擺動(dòng)噴嘴通過使板的中心和邊緣的噴霧壓力不同，可以進(jìn)一步提高整個(gè)表面的均勻性。

蝕刻工藝的優(yōu)點(diǎn)

因?yàn)榻饘傥g刻工藝是用化學(xué)溶液蝕刻的。

與原材料保持高度一致性。它不會(huì)改變材料的性能、應(yīng)力、硬度、抗拉強(qiáng)度、屈服強(qiáng)度和延展性?；鶎蛹庸すに囋谠O(shè)備內(nèi)以霧化狀態(tài)蝕刻，表面無明顯壓力。

沒有毛刺。在產(chǎn)品加工過程中，全程無壓緊力，不會(huì)出現(xiàn)壓接、磕碰、壓點(diǎn)。

可配合后工序沖壓完成產(chǎn)品的個(gè)性化成型動(dòng)作。掛點(diǎn)法可用于全板電鍍、粘合、電泳、發(fā)黑等，性價(jià)比更高。

還可以應(yīng)對(duì)小型化和多樣化，周期短，成本低。

蝕刻加工應(yīng)用領(lǐng)域

消費(fèi)類電子產(chǎn)品

過濾分離技術(shù)

航天

醫(yī)用器材

精密機(jī)械

車

高端工藝品

硬質(zhì)合金是一種由硬質(zhì)合金和難熔金屬的硬質(zhì)化合物經(jīng)粉末冶金工藝制成的硬質(zhì)合金。由于其良好的硬度和強(qiáng)度，它被廣泛用于許多領(lǐng)域。隨著對(duì)硬質(zhì)合金材料的高溫性能和耐腐蝕性的要求越來越高，現(xiàn)有硬質(zhì)合金材料的性能難以滿足其使用要求。在過去的30年中，許多學(xué)者對(duì)WC基化合物進(jìn)行了實(shí)驗(yàn)研究，并獲得了一系列研究成果。

WC金屬

WC-Co

碳化鎢中廣泛使用的膠凝材料是鈷。 WC Co系統(tǒng)已被廣泛研究。 CO的添加使WC具有良好的潤濕性和粘附性。此外，如圖13.2所示，添加CO還可以顯著提高強(qiáng)度和韌性。

圖13.3 WC Co粉的背散射電子顯微照片，顯示了外部和橫截面結(jié)構(gòu)：（a），（b）F8； （c），（d）M8； （E），（f）C8。

他對(duì)F8，M8和C8粉末及其拋光部分進(jìn)行了反向散射電子成像。觀察到所有粉末均具有典型的球形。 F8粉末顯示出細(xì)小碳化物的密集堆積，而M8和C8粉末顯示出具有一些孔的相對(duì)松散的堆積結(jié)構(gòu)。在拋光部分，所有樣品均顯示出明顯的散射現(xiàn)象，并且硬度和耐磨性與鈷含量成反比。維氏硬度（HV）在1500到2000 HV30之間變化，斷裂韌性在7到15 MPa M1 / 2之間。這種顯著變化是碳化物組成，微觀結(jié)構(gòu)和化學(xué)純度的函數(shù)。

一般來說，粒度越小，硬度越高，耐磨性越好。 CO的體積分?jǐn)?shù)越高，斷裂韌性越高，但硬度和耐磨性越低（Jia等，2007）。因此，為了獲得更好的性能，不可避免地要考慮使用其他水泥材料代替。

另一方面，由于上述原因，策略上不科學(xué)并且容易影響價(jià)格趨勢(shì)。此外，WC和粉塵的結(jié)合令人擔(dān)憂，因?yàn)樗鼈儽热魏我淮问褂酶咧旅浴?/p>

鎢鎳

鎳比鈷便宜且易于獲得。它具有良好的增韌性能。它可用于改善苛刻環(huán)境下的腐蝕/氧化性能，高溫強(qiáng)度和耐磨性。與WC Co合金相比，材料的可塑性較低。由于鎳在WC中溶解良好，因此可以用作WC基材的粘合劑，從而在它們之間形成牢固的結(jié)合。

WC-Ag

Ag的添加使WC成為一種耐電弧材料。在過載電流的作用下，WC通常負(fù)載在開關(guān)設(shè)備中，這可歸因于后者的眾所周知的電接觸電阻（RC）。值得一提的是，WC Ag復(fù)合材料的電阻率隨Ag含量的增加而降低，而硬度隨Ag含量的增加而降低，這是由于WC和Ag的硬度差異很大。另外，粗WC顆粒具有非常低且穩(wěn)定的接觸電阻。

圖13.4顯示了開關(guān)產(chǎn)生的平均電接觸電阻（RC）

具有不同銀含量和WC粒度的11e50循環(huán)，因?yàn)橛^察到大多數(shù)材料的RC在10個(gè)開關(guān)循環(huán)后均保持穩(wěn)定。銀的接觸電阻在顆粒大小為4 mm的WC中為50-55 wt%（體積比60%和64.6%）之間，在顆粒大小為WC的WC中為55-60 wt%（體積比64.6%和69%）之間。 0.8和1.5毫米。因此，這確定了投資的初始組成，其中銀基質(zhì)完全互連。對(duì)于固定組件，觀察到接觸電阻在1.5和4 mm WC粒度之間減小，這也標(biāo)志著滲透閾值。

WC-Re

科學(xué)家使用碳化鎢來增強(qiáng)rh，以獲得比WC Co更好的性能，因?yàn)镽E可以帶來高溫硬度和良好的結(jié)合

圖13.4在第11至第50次循環(huán)中，不同Ag含量和WC顆粒尺寸下的平均接觸電阻與WC基材接觸電阻的比率為co或Ni。根據(jù)WC粗晶的顯微組織特征（含量為20% RE），描述了WC粗晶保留在CO中并繼續(xù)形成HCP結(jié)構(gòu)，從而提高了合金的硬度。研究人員還加強(qiáng)了對(duì)WC Ni的研究，發(fā)現(xiàn)了類似的推論。由于具有最高的硬度和兩倍于WC Co的耐久性，該合金被用于制造具有競(jìng)爭(zhēng)力的工具零件。當(dāng)冷壓WC和Re粉末并采用獲得專利的熱壓工藝時(shí)，觀察到超過2400 kg / mm?2的HV（而WC-Co為1700 kg / mm?2）

WC金屬間化合物

WC-FeAl

在過去的幾十年中，金屬間化合物作為陶瓷粘合劑引起了人們的注意。鋁化鐵具有優(yōu)異的抗氧化性和抗腐蝕性，低毒性，高硬度，良好的耐磨性，高溫穩(wěn)定性和良好的潤濕性。它在熱力學(xué)上適合作為粘合劑的WC。 WC FeAl和WC Co的硬度和斷裂韌性基本相同。 WC Co合金的硬度和耐磨性與常規(guī)WC Co合金相似。可以認(rèn)為，如果可以優(yōu)化晶粒尺寸，則可以替代傳統(tǒng)的WCCo。通過不同的球磨和/或干燥工藝制備的WC FeAl混合粉末的粒度分布曲線如圖13.5所示。圖13.5中的三條曲線具有雙峰分布。在圖13.5中，較小粒徑的左峰對(duì)應(yīng)于單個(gè)WC顆粒的左峰。較大粒徑的正確峰值對(duì)應(yīng)于包含一些WC顆粒的FeAl碎片的峰值。當(dāng)正確的峰移動(dòng)時(shí)，左峰不取決于研磨和/或干燥過程。 DR粉末（脫水乙醇作為快速干燥的溶劑）的正確峰移至其他兩種粉末的相應(yīng)峰。

圖13.5由各種粉末工藝制備的WC-FeAl混合粉末的粒度分布。

WC陶瓷

WC-MgO

Wc-mgo復(fù)合材料由于在WC基體中添加了MgO顆粒而被廣泛使用，這對(duì)硬度幾乎沒有影響，并且顯著提高了材料的韌性。硬度與韌性成反比，但是在這種合金的情況下，當(dāng)硬度損失非常小時(shí)獲得韌性。在研究材料中加入少量的VC，Cr3C2和其他晶粒長大抑制劑，不僅可以控制燒結(jié)過程中的晶粒長大，而且可以提高材料的機(jī)械性能。

WC-Al2O3

這里必須提到的是，Al2O3用作WC的增強(qiáng)材料，反之亦然，因?yàn)樗鼈兙哂谐錾臋C(jī)械和物理性能。

燒結(jié)溫度和保溫時(shí)間對(duì)wc-40vol% Al2O3復(fù)合材料的顯微組織和力學(xué)性能有重要影響。隨著燒結(jié)溫度和保溫時(shí)間的增加，相對(duì)密度和粒徑增加。同時(shí)，高壓值和斷裂韌性值先增大然后減小。裂紋路徑的微觀結(jié)構(gòu)揭示了裂紋橋接和裂紋變形的存在。在wc-40vol% Al 2O 3復(fù)合材料中，主要的增韌機(jī)理是產(chǎn)生次生和橫向裂紋。另一項(xiàng)研究表明，HV約為20e25gpa，斷裂韌性為5e6mpa.m1 / 2。

圖13.6顯示了硬度，斷裂韌性和橫向斷裂強(qiáng)度隨氧化鋁含量的變化趨勢(shì)。應(yīng)該注意的是，這些值與報(bào)道的值有很大的不同（Mao et al。，2015）。純WC具有最高的硬度和最低的斷裂韌性。 Al 2 O 3的添加提高了斷裂韌性，但純氧化鋁的硬度低于純WC的硬度，wc-al2o3復(fù)合材料的硬度降低。圖13.6中的不同結(jié)果表明，機(jī)械性能不僅取決于氧化鋁的含量，還取決于生產(chǎn)工藝和不同基材的等級(jí)。 

WC磨料

WC立方氮化硼

由于CBN具有出色的硬度，熱穩(wěn)定性和與鐵的反應(yīng)活性，因此在WC Co中添加CBN可以改善材料的耐磨性，硬度和機(jī)械性能。一旦將CBN增強(qiáng)到WC基質(zhì)中，就會(huì)產(chǎn)生強(qiáng)附著力。另外，通過裂紋變形或CBN顆粒的橋接可以得到更好的斷裂韌性。 CBN添加過程中的兩個(gè)主要障礙是CBN向hBN的轉(zhuǎn)化以及B和N之間強(qiáng)的共價(jià)鍵結(jié)合，這導(dǎo)致CBN和硬質(zhì)合金的燒結(jié)能力低。

WC鉆石

WC金剛石具有出色的斷裂韌性，抗裂紋擴(kuò)展性和抗反射性。這種材料只能在熱力學(xué)條件下生產(chǎn)，以防止金剛石變成石墨。通過更多的研究來改善這種材料的性能，我們可以彌補(bǔ)巨大的成本缺口，這是非常必要的。

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簡(jiǎn)介通過將鋼加熱到高于臨界溫度Ac3（亞共析鋼）或Ac1（亞共析鋼）的溫度來淬火鋼，保持一段時(shí)間，以便全部或部分奧氏體化，然后在溫度高于臨界冷卻速率?？焖倮鋮s至Ms（或等溫附近的Ms）馬氏體（或貝氏體）熱處理工藝以下。諸如鋁合金，銅合金，鈦合金，鋼化玻璃等材料的固溶處理，或具有快速冷卻的熱處理工藝通常也稱為淬火。淬火是一種常見的熱處理工藝，主要用于增加材料的硬度。通常從淬火介質(zhì)來看，可分為水淬，油淬，有機(jī)淬火。隨著科學(xué)技術(shù)的發(fā)展，出現(xiàn)了一些新的淬火工藝。1高壓風(fēng)冷淬火方法工件在強(qiáng)惰性氣體中快速均勻地冷卻，防止表面氧化，避免開裂，減少變形，確保所需的硬度，主要用于工具鋼的淬火。這項(xiàng)技術(shù)最近發(fā)展很快，應(yīng)用范圍也大大擴(kuò)展了。目前，真空氣體淬火技術(shù)發(fā)展迅速，負(fù)壓（<1×105 Pa）高流量氣體冷卻繼之以氣體冷卻和高壓（1×105?4×105 Pa）10×105 Pa）空氣冷卻，超高壓（10×105?20×105 Pa）風(fēng)冷等新技術(shù)，不僅大大提高了風(fēng)冷的真空淬火能力，而且淬火后工件表面亮度好，變形小，但還具有高效，節(jié)能，無污染等特點(diǎn)。真空高壓氣冷淬火的用途是材料的淬火和回火，不銹鋼和特殊合金的固溶，時(shí)效，離子滲碳和碳氮共滲，以及釬焊后的真空燒結(jié)，冷卻和淬火。用6×105 Pa高壓氮?dú)饫鋮s淬火，只能將負(fù)載冷卻散開，高速鋼（W6Mo5Cr4V2）可以硬化到70?100 mm，高合金熱作模具鋼可達(dá)25?100 mm，金冷工作模具鋼（例如Cr12）可達(dá)80?100毫米。當(dāng)用10×10 5 Pa的高壓氮?dú)獯慊饡r(shí)，冷卻的負(fù)荷會(huì)很大，與6×10 5 Pa的冷卻相比，負(fù)荷密度會(huì)增加30%至40%。當(dāng)用20×10 5 Pa的超高淬火時(shí)壓力為氮?dú)饣蚝夂偷獨(dú)獾幕旌衔?，冷卻后的負(fù)載很稠密，可以捆綁在一起。密度為6×105 Pa的80%氮?dú)饫鋮s至150%，可以冷卻所有高速鋼，高合金鋼，熱作工具鋼和Cr13%鉻鋼以及更多的合金油淬火鋼，例如更大型的9Mn2V鋼。具有獨(dú)立冷卻室的雙室風(fēng)冷淬火爐具有比同類單室爐更好的冷卻能力。 2×105 Pa氮?dú)饫鋮s雙室爐具有與4×105 Pa單室爐相同的冷卻效果。但是，運(yùn)營成本低，維護(hù)成本低。隨著我國基礎(chǔ)材料工業(yè)（石墨，鉬等）及輔助部件（電機(jī)）等水平的提高。因此，在保持我國發(fā)展雙腔壓力和高壓風(fēng)冷淬火爐發(fā)展的同時(shí)，要改善6×105 Pa單腔高壓真空保鮮。圖1高壓風(fēng)冷冷卻的真空爐2強(qiáng)淬火方法常規(guī)淬火通常是用油，水或聚合物溶液冷卻，強(qiáng)淬火規(guī)則是用水或低濃度的鹽水。強(qiáng)淬火的特征在于極快的冷卻，而不必?fù)?dān)心鋼的過度變形和開裂。常規(guī)淬火冷卻至淬火溫度時(shí)，鋼的表面處于拉力或低應(yīng)力狀態(tài)，而在淬火過程中強(qiáng)淬火，工件心臟仍處于熱態(tài)而停止冷卻，從而形成表面壓應(yīng)力。在嚴(yán)重的淬火條件下，當(dāng)馬氏體相變區(qū)的冷卻速率高于30℃/ s時(shí)，鋼表面的過冷奧氏體承受1200 MPa的壓應(yīng)力，因此淬火后的鋼的屈服強(qiáng)度原理：至少奧氏體增加25%。原理：鋼由于奧氏體溫度淬火，表面和心臟之間的溫差會(huì)導(dǎo)致內(nèi)部應(yīng)力。相變的比容和相變塑料的比容也會(huì)引起附加的相變應(yīng)力。如果熱應(yīng)力和相變應(yīng)力疊加，即總應(yīng)力超過材料的屈服強(qiáng)度，則會(huì)發(fā)生塑性變形；如果應(yīng)力超過熱鋼的拉伸強(qiáng)度，將形成淬火裂紋。在強(qiáng)化淬火過程中，由于奧氏體-馬氏體相變的比體積變化，由相變可塑性引起的殘余應(yīng)力和殘余應(yīng)力增加。在強(qiáng)烈冷卻下，工件表面立即冷卻至浴溫，心臟溫度幾乎不變?？焖倮鋮s會(huì)產(chǎn)生高拉伸應(yīng)力，使表面層收縮并受到心臟壓力的平衡。溫度梯度的增加會(huì)增加由初始馬氏體相變引起的拉應(yīng)力，而馬氏體相變開始溫度Ms的增加將由于相變可塑性而導(dǎo)致表面層膨脹，表面拉應(yīng)力將顯著降低并轉(zhuǎn)變進(jìn)入壓應(yīng)力后，表面壓應(yīng)力與產(chǎn)生的表面馬氏體數(shù)量成正比。該表面壓應(yīng)力確定心臟是在壓縮條件下經(jīng)歷馬氏體轉(zhuǎn)變，還是在進(jìn)一步冷卻時(shí)使表面拉應(yīng)力反轉(zhuǎn)。如果心臟體積擴(kuò)張的馬氏體轉(zhuǎn)變足夠大，并且表面馬氏體非常硬而脆，它將使表面層由于應(yīng)力反轉(zhuǎn)而破裂。為此，鋼表面應(yīng)出現(xiàn)壓應(yīng)力，并應(yīng)盡早出現(xiàn)馬氏體相變。強(qiáng)的淬火試驗(yàn)和鋼的淬火性能：強(qiáng)淬火方法的優(yōu)點(diǎn)是在表面形成壓應(yīng)力，降低了開裂的風(fēng)險(xiǎn)并提高硬度和強(qiáng)度。表面形成100%馬氏體時(shí)，鋼會(huì)被賦予最大的硬化層，它可以代替價(jià)格更昂貴的碳素鋼，強(qiáng)淬火也可以促進(jìn)鋼的均勻機(jī)械性能并產(chǎn)生最小的工件變形。零件淬火后，在交變載荷下的使用壽命可以增加一個(gè)數(shù)量級(jí)。 [1]圖2強(qiáng)淬火裂紋形成幾率與冷卻速度的關(guān)系3水-空氣混合物的冷卻方法通過調(diào)節(jié)水和空氣的壓力以及霧化噴嘴與工件表面之間的距離，水-空氣混合物的冷卻能力可以變化并且冷卻可以均勻。生產(chǎn)實(shí)踐表明，利用該法對(duì)復(fù)合碳鋼或合金鋼零件的形狀進(jìn)行感應(yīng)淬火表面淬火，可有效防止淬火裂紋的產(chǎn)生。圖3水-空氣混合物4沸水淬火方法采用100℃沸水冷卻，可以獲得更好的淬火效果，用于淬火或正火鋼。目前，該技術(shù)已成功應(yīng)用于球墨鑄鐵淬火。以鋁合金為例：根據(jù)現(xiàn)行的鋁合金鍛件和鍛件的熱處理規(guī)范，淬火水溫度一般控制在60℃以下，淬火水溫度低，冷卻速度快，殘留量大。淬火后產(chǎn)生應(yīng)力。在最終加工中，由于表面形狀和尺寸的不一致，內(nèi)部應(yīng)力失衡，導(dǎo)致殘余應(yīng)力的釋放，導(dǎo)致加工部件的變形，彎曲，橢圓形和其他變形的零件成為不可逆的最終廢品損失嚴(yán)重。例如：螺旋槳，壓氣機(jī)葉片和其他鋁合金鍛件加工后變形明顯，導(dǎo)致零件尺寸公差大。淬火水溫度從室溫（30-40℃）升高到沸水（90-100℃），平均鍛件殘余應(yīng)力降低約50%。 [2]圖4沸水淬火示意圖5熱油淬火方法使用熱油淬火，使工件在進(jìn)一步冷卻之前等于或接近Ms點(diǎn)的溫度，以使溫度差最小，可有效防止淬火工件變形和開裂。小尺寸的合金工具鋼模具在160?200℃的熱油淬火中冷軋，可以有效減少變形并避免開裂。圖5熱油淬火圖6低溫處理方法將淬火的工件從室溫連續(xù)冷卻至較低溫度，以便殘留的奧氏體繼續(xù)轉(zhuǎn)變?yōu)轳R氏體，其目的是提高鋼的硬度和耐磨性，提高工件的結(jié)構(gòu)穩(wěn)定性和尺寸穩(wěn)定性，并有效地提高刀具壽命。用于材料加工方法的冷卻介質(zhì)。低溫處理技術(shù)首先應(yīng)用于磨損工具，模具工具的材料，后來擴(kuò)展到合金鋼，硬質(zhì)合金等，使用這種方法可以改變金屬材料的內(nèi)部結(jié)構(gòu)，從而提高機(jī)械性能和加工性能，這是目前是最新的增韌工藝之一。低溫處理（Cryogenic treatment），也稱為超低溫處理，一般是指在-130℃以下的材料進(jìn)行加工以提高材料的整體性能。早在100年前，人們就開始對(duì)表部件進(jìn)行冷處理，發(fā)現(xiàn)它們可以提高強(qiáng)度，耐磨性，尺寸穩(wěn)定性和使用壽命。低溫處理是在1960年代基于普通冷處理技術(shù)開發(fā)的一項(xiàng)新技術(shù)。與常規(guī)冷處理相比，深冷處理可以進(jìn)一步提高材料的力學(xué)性能和穩(wěn)定性，具有廣闊的應(yīng)用前景。深冷處理機(jī)理：深冷處理后，金屬材料（主要是鑄型）內(nèi)部結(jié)構(gòu)中殘留的奧氏體。材料）轉(zhuǎn)變?yōu)轳R氏體，并且析出的碳化物也在馬氏體中析出，從而可以消除馬氏體中的殘余應(yīng)力，同時(shí)也增強(qiáng)了馬氏體基體，因此其硬度和耐磨性也將提高。硬度增加的原因是由于一部分殘余奧氏體轉(zhuǎn)變成馬氏體。韌性的提高歸因于分散和少量的η-Fe3C沉淀。同時(shí)，馬氏體的碳含量降低，晶格畸變降低，塑性提高。低溫處理設(shè)備主要由液氮罐，液氮傳輸系統(tǒng)，深冷箱和控制系統(tǒng)組成。在本申請(qǐng)中，低溫處理重復(fù)幾次。典型過程如：1120℃油淬+ -196℃×1h（2-4）深低溫處理+ 200℃×2h回火。經(jīng)過組織處理后，奧氏體發(fā)生了轉(zhuǎn)變，但也從淬火的馬氏體彌散體中析出，該彌散體與超細(xì)碳化物的基體具有高度連貫的關(guān)系，隨后在200℃進(jìn)行低溫回火后，超細(xì)碳化物的生長散布了，數(shù)量和分散度明顯增加。低溫處理重復(fù)多次。一方面，在先前的低溫冷卻時(shí)，超細(xì)碳化物從殘留奧氏體轉(zhuǎn)變而來的馬氏體中析出。另一方面，細(xì)小的碳化物繼續(xù)在淬火的馬氏體中沉淀。重復(fù)的過程可以使基體的抗壓強(qiáng)度，屈服強(qiáng)度和沖擊韌性提高，提高鋼的韌性，同時(shí)使沖擊耐磨性得到明顯提高。圖6低溫處理裝置示意圖某些工件對(duì)尺寸的嚴(yán)格要求，不允許加工中由于熱應(yīng)力引起的過度變形，應(yīng)控制低溫處理的冷卻速度。另外，為了確保設(shè)備內(nèi)部溫度場(chǎng)的均勻性并減少溫度波動(dòng)，低溫處理系統(tǒng)的設(shè)計(jì)應(yīng)考慮系統(tǒng)溫度控制的準(zhǔn)確性和流場(chǎng)布置的合理性。在系統(tǒng)設(shè)計(jì)中還應(yīng)注意滿足能耗少，效率高，操作簡(jiǎn)便等要求。這些是低溫處理系統(tǒng)的當(dāng)前發(fā)展趨勢(shì)。另外，隨著最低溫度的降低和制冷效率的提高，也有望將一些制冷溫度從室溫?cái)U(kuò)展到低溫的發(fā)展中的制冷系統(tǒng)發(fā)展成無液體的低溫處理系統(tǒng)。 [3]參考：[1]樊東黎。強(qiáng)烈淬火-一種新的強(qiáng)化鋼的熱處理方法[J]。力學(xué)學(xué)報(bào)，2010,42（2）：155-159熱處理，2005，20（4）：1-3 [2]宋微，郝冬梅，王成江。關(guān)鍵詞：沸水淬火，鋁合金鍛件，組織與機(jī)械性能，影響鋁加工，2002，25（2）：1-3 [3]夏雨亮，金滔，湯珂。深冷處理工藝及設(shè)備的發(fā)展現(xiàn)狀和展望[J]。低溫與特氣，2007，25（1）：1-3
資料來源：Meeyou Carbide

一，分子束外延輪廓在超高真空環(huán)境下，具有一定熱能的一個(gè)或多個(gè)分子（原子）束流噴射到晶體基板上，基板表面反應(yīng)過程中的分子在“飛行”過程中幾乎不會(huì)與性能：一種真空沉積方法起源：20世紀(jì)70年代初期，美國貝爾實(shí)驗(yàn)室應(yīng)用：外延生長原子能級(jí)精確控制超薄的多層二維結(jié)構(gòu)材料和器件（超字符，量子阱，調(diào)制摻雜異質(zhì)結(jié)，量子陰：激光器，高電子遷移率晶體管等）；結(jié)合其他工藝，還可以制備一維和零維納米材料（量子線，量子點(diǎn)等）。MBE的典型特征：（1）從源爐中釋放出的分子（原子）達(dá)到以“分子束”流的形式存在于基材表面。通過石英晶體膜厚的監(jiān)測(cè)，可以嚴(yán)格控制生長速度。（2）分子束外延生長速度較慢，約為0.01-1nm / s?？梢詫?shí)現(xiàn)單原子（分子）層外延，具有優(yōu)異的膜厚可控性。（3）通過調(diào)節(jié)源和基板之間擋板的開閉，可以嚴(yán)格控制膜的成分和雜質(zhì)濃度，并且可以實(shí)現(xiàn)選擇性外延生長。（4）非熱平衡生長，襯底溫度可以低于平衡溫度，實(shí)現(xiàn)低溫生長，可以有效減少互擴(kuò)散和自摻雜。（5）具有反射性高-能量電子衍射儀（RHEED）等設(shè)備，可以實(shí)現(xiàn)原始價(jià)格觀察，實(shí)時(shí)監(jiān)控。生長速度相對(duì)較慢，既有MBE的優(yōu)勢(shì)，又有其不足之處，不適合厚膜生長和批量生產(chǎn)。硅分子束外延1基本概況硅分子束外延包括均質(zhì)外延，異質(zhì)外延。硅分子束外延是硅的外延生長通過原子，分子或離子的物理沉積在適當(dāng)加熱的硅基板上（或與硅有關(guān)的材料上）。（1）在外延期間，基板溫度較低。（2）同時(shí)摻雜。（3）系統(tǒng)要保持高真空狀態(tài)。（4）要特別注意原子清潔表面。圖1硅MBE2的工作原理示意圖硅分子束外延的發(fā)展歷史相對(duì)于CVD缺陷而發(fā)展CVD缺陷：襯底高溫，1050oC，到嚴(yán)重的摻雜（高溫）。最初的分子束外延：將硅襯底加熱到合適的溫度，將硅真空蒸發(fā)到硅襯底上，進(jìn)行外延生長。生長標(biāo)準(zhǔn)：入射分子充分移動(dòng)到襯底的熱表面，并以下列形式排列： 3硅分子束外延的重要性MBE硅是在嚴(yán)格控制的低溫系統(tǒng)中進(jìn)行的（1）可以很好地控制雜質(zhì)濃度達(dá)到原子水平。未摻雜濃度控制在<3×1013 / cm3。（2）外延可以在最佳條件下進(jìn)行而沒有缺陷。（3）外延層的厚度可以控制在單原子層的厚度之內(nèi)，可手動(dòng)設(shè)計(jì)的幾納米至幾十納米的超晶格外延，并制備出性能優(yōu)異的新型功能材料。（4）硅的均質(zhì)外延，硅的異質(zhì)外延。4外延生長設(shè)備發(fā)展方向：可靠性，高可靠性性能和通用性缺點(diǎn)：價(jià)格高，復(fù)雜，運(yùn)行成本高。適用范圍：可用于硅MBE，化合物MBE，III-V MBE，正在開發(fā)的金屬半導(dǎo)體MBE?；竟餐卣鳎海?）基本的超高真空系統(tǒng)，外延室，諾森加熱室;（2）分析裝置，LEED，SIMS，Yang EED等;（3）注入室。圖2硅分子束外延系統(tǒng)示意圖（1）沖浪電子束轟擊硅靶的王牌，使其易于產(chǎn)生硅分子束。為了避免硅分子束向側(cè)面的輻射造成不利影響，大面積的屏幕屏蔽和準(zhǔn)直是必要的。（2）耐加熱硅陰極不能產(chǎn)生強(qiáng)分子束，其他石墨柑桔罐都有Si-C染色后，最好的方法是使電子束蒸發(fā)以產(chǎn)生硅源。因?yàn)?，某些部位的硅MBE溫度較高，容易蒸發(fā)，所以硅對(duì)蒸發(fā)壓力要求較低的蒸發(fā)源具有較高的溫度。同時(shí)，光束的密度和掃描參數(shù)要控制。使硅熔池恰好位于硅棒中，硅棒就變成高純度的柑橘。監(jiān)視分子束有幾種：（1）石英晶體通常用于監(jiān)視束流，適當(dāng)?shù)剡M(jìn)行束屏蔽和冷卻，可以滿足要求結(jié)果，但噪聲會(huì)影響穩(wěn)定性。幾微米后，石英晶體失去線性。頻繁交換，主系統(tǒng)經(jīng)常充氣，不利于工作。（2）離子表小，測(cè)量分子束壓力，而不是測(cè)量分子束通量。由于沉積在系統(tǒng)上的成分離開了標(biāo)準(zhǔn)。（3）低能電子束通過分子束，利用激發(fā)熒光檢測(cè)出電子。原子被激發(fā)并迅速降解為基態(tài)以產(chǎn)生uv熒光，并且光密度與光學(xué)聚焦后的光束密度成正比。對(duì)硅源進(jìn)行反饋控制。不足：切斷電子束，大部分的紅外熒光和背景輻射會(huì)使信噪比惡化到不穩(wěn)定的程度。 （4）原子吸收光譜，監(jiān)測(cè)摻雜原子的束密度。在間歇的束流下，分別通過251.6nm和294.4nm的光輻射檢測(cè)到Si和Ga。束通過原子束的吸收強(qiáng)度轉(zhuǎn)換為原子束密度并獲得相應(yīng)的比率。分子束外延（MBE）襯底基底是一個(gè)難點(diǎn)，MBE是冷壁工藝，即硅襯底加熱到1200℃，環(huán)境到室溫。另外，確保硅晶片溫度均勻。希爾電阻耐火金屬和石墨陰極，背面輻射加熱，并將整個(gè)加熱部件安裝在液氮冷卻的容器中，以減少真空部件的熱輻射。旋轉(zhuǎn)基板以確保均勻加熱。自由偏轉(zhuǎn)，可以增強(qiáng)二次注入的摻雜效果。
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1, Review of Organic Halide Perovskite – related Photoelectric PropertiesFigure 1 Spectral position and PL peakOrganic halide perovskites are widely used in optoelectronics research. Methyl ammonium and formamidine lead iodide as photovoltaics show excellent photoelectric properties and stimulate researchers’ enthusiasm for light-emitting devices and photodetectors. Recently, the University of Toronto Edward H. Sargent (Correspondent) team of organic metal halide perovskite optical and electrical properties of the material were studied. Outlines how material composition and form are associated with these attributes, and how these properties ultimately affect device performance. In addition, the team also analyzed different material properties of the perovskite materials, in particular the bandgap, mobility, diffusion length, carrier lifetime and trap density.The Electrical and Optical Properties of Organometal Halide Perovskites Relevant to Optoelectronic Performance（Adv.Mater.,2017,DOI: 10.1002/adma.201700764）2, Advanced Materials Overview: 2D optoelectronic applications of organic materials Figure 2 Several key steps in the application of two-dimensional organic materialsThe 2D material with atomic thin structure and photoelectron properties has attracted the interest of researchers in applying 2D materials to electronics and optoelectronics. In addition, as a two-dimensional material series of emerging areas, the organic nanostructure assembled into 2D form provides molecular diversity, flexibility, ease of processing, light weight, etc., for optoelectronic applications provides an exciting prospect. Recently, Tianjin University, Professor Hu Wenping, Ren Xiaochen assistant researcher (common newsletter) and others reviewed the application of organic two-dimensional materials in optoelectronic devices. Examples of materials include 2D, organic, crystalline, small molecules, polymers, self- Covalent organic skeleton. The application of 2D organic crystal fabrication and patterning technology is also discussed. Then the application of optoelectronic devices is introduced in detail, and the prospect of 2D material is briefly discussed.2D Organic Materials for Optoelectronic Applications（Adv.Mater.,2017,DOI: 10.1002/adma.201702415）3, Advanced Materials Review: 2D Ruddlesden-Popper Perovskite PhotonicsFigure 3 Schematic diagram of 3D and 2D perovskite structuresThe traditional 3D organic-inorganic halide perovskite has recently undergone unprecedented rapid development. However, their inherent instabilities in moisture, light and calories remain a key challenge before commercialization. In contrast, the emerging two-dimensional Ruddlesden-Popper perovskite has received increasing attention due to its environmental stability. However, 2D perovskite research has just started. Recently, the University of Fudan University, Liang Ziqi (Corresponding author) team published a review first introduced 2D perovskite and 3D control of a detailed comparison. And then discussed the two-dimensional perovskite organic interval cationic engineering. Next, quasi-two-dimensional perovskites between 3D and 2D perovskites were studied and compared. In addition, 2D perovskite unique exciton properties, electron-phonon coupling and polaron are also shown. Finally, a reasonable summary of the structure design, growth control and photophysics research of 2D perovskite in high performance electronic devices is presented.2D Ruddlesden–Popper Perovskites for Optoelectronics（Adv.Mater.,2017,DOI: 10.1002/adma.201703487）4, Science Advances Summary: Lead Halide Perovskite: Crystal-Liquid Binary, Phonon Glass Electronic Crystals and Great Polaron FormationFigure 4 CH3NH3PbX3 perovskite structureLead anodized perovskite has proven to be a high performance material in solar cells and light emitting devices. These materials are characterized by the expected coherent band transport of crystalline semiconductors, as well as the dielectric response and phonon dynamics of the liquid. This “crystal-liquid” duality means that lead halide perovskites belong to phonon glass electron crystals – a class of thermoelectric materials that are considered to be the most efficient. Recently, the University of Columbia Zhu Xiaoyang (communication author) team reviewed the crystal-liquid duality, the resulting dielectric response responsible for the formation and selection of carrier polaron, which causes perovskite with defect tolerance, moderate Of the carrier mobility and the combined performance of the radiation. Large polaron formation and phonon glass characteristics can also explain the significant reduction in carrier cooling rates in these materials.Lead halide perovskites: Crystal-liquid duality, phonon glass electron crystals, and large polaron formation（Sci. Adv.,2017,DOI:10.1126/sciadv.1701469）5, Progress in Polymer Science Review: Lithography of silicon-containing block copolymersFig.5 Melt phase diagram of diblock copolymerRecently, the National Tsinghua University Rong-Ming Ho (Correspondent) and others published a summary of the different methods through the preparation of ordered block copolymer (BCP) film the latest progress, focusing on the use of silicon-containing BCP as lithography applications. With the advantages of Si-containing blocks, these BCPs have smaller feature sizes due to their high resolution, large segregation intensity and high etch contrast. Considering that poly (dimethylsiloxane) (PDMS) has been extensively studied in Si-containing BCPs, the possibility of photolithography using PDCP-containing BCP has been demonstrated through previous and ongoing studies. Subsequent sections detail the main results of the DSA approach. The new trend of lithographic printing application and the application of photolithography nano – pattern using silicon – containing BCPs are also discussed. Finally, the conclusion and prospect of BCP lithography are introduced.Silicon-Containing Block Copolymers for Lithographic Applications（Prog. Polym. Sci.,2017,DOI:10.1016/j.progpolymsci.2017.10.002）6, Angewandte Chemie International Edition Overview: CH3NH3PbI3 perovskite solar cell theoretical studyFigure 6 Electronic density patternPower conversion efficiency (PCEs) of more than 22% of the hybridized perovskite perovskite solar cells (PSCs) has attracted considerable attention. Although perovskite plays an important role in the operation of PSCs, the basic theory associated with perovskite remains unresolved. Recently, Professor Xun Nining (Communication Author) of Xi’an University of Architecture and Technology, according to the first principle, evaluated the existing theory of structure and electronic properties, defects, ion diffusion and transfer current of CH3NH3PbI3 perovskite, and ion transport Influence on PSC Current – Voltage Curve Hysteresis. The moving current associated with the possible ferroelectricity is also discussed. And emphasizes the benefits, challenges and potential of perovskite for PSCs.Theoretical Treatment of CH3NH3PbI3 Perovskite Solar Cells（Angew. Chem. Int. Ed.,2017,DOI: 10.1002/anie.201702660）7, Chemical Society Reviews Overview: Reductive Batteries for Electromechanical Active Materials for Molecular EngineeringFigure 7 Molecular engineering for redox substances for sustainable RFBAs an important large energy storage system, redox batteries (RFBs) have high scalability and independent energy and power control capabilities. However, conventional RFB applications are subject to performance and limitations on high cost and environmental issues associated with the use of metal-based redox substances. Recently, the University of Texas at Austin Guihua Yu (communication author) team proposed the design of these new redox substances system molecular engineering program. The article provides a detailed synthesis strategy for modifying organometallic and organometallic redox substances in terms of solubility, oxidation-reduction potential and molecular size. And then introduced recent advances covering the reaction mechanism of the redox species classified by its molecular structure, the specific functionalization methods and electrochemical properties. Finally, the author analyzes the future development direction and challenge of this emerging research field.Molecular engineering of organic electroactive materials for redox flow batteries （Chem.Soc.Rev.,2017,DOI: 10.1039/C7CS00569E）8, Chemical Society Reviews Overview: Atomic level for energy storage and conversion Non-layered nanomaterialsFigure 8 Atomic-grade layered and non-layered nanomaterialsSince the discovery of graphene, the two-dimensional nanomaterials with large atomic thickness and large lateral dimension are highly studied because of their high specific surface area, heterogeneous electronic structure and attractive physical and chemical properties. Recently, Wulonggong University Dushi University academician (communication author) team comprehensively summed up the atomic thickness of non-layered nano-materials preparation method, studied its heterogeneous electronic structure, the introduction of electronic structure operation strategy, and outlined its energy storage and conversion Applications, with particular emphasis on lithium-ion batteries, sodium ion batteries, oxygen, CO2 reduction, CO oxidation reaction. Finally, based on the current research progress, put forward the future direction – in practical application to enhance the performance and new features to explore.Atomically thin non-layered nanomaterials for energy storage and conversion （Chem.Soc.Rev.,2017,DOI:10.1039/C7CS00418D）9, Chemical Reviews Overview: Electrochemical Applications in the Synthesis of Heterocyclic StructuresFigure 9 Mechanism of electro-induced cationic chain reactionThe heterocycle is one of the largest organic compounds to date, and the preparation and transformation of heterocyclic structures have been of great interest to organic chemistry researchers. Various heterocyclic structures are widely found in biologically active natural products, organic materials, agrochemicals and drugs. When people notice that about 70% of all drugs and agrochemicals have at least one heterocycle, people can not ignore them importance. Recently, Professor Zeng Chengchao of Beijing University of Technology (Correspondent Author) team reviewed the progress of electrochemical construction of heterocyclic compounds published by intramolecular and intermolecular cyclization since 2000.Use of Electrochemistry in the Synthesis of Heterocyclic Structures（Chem. Rev.,2017,DOI:10.1021/acs.chemrev.7b00271）
資料來源：Meeyou Carbide

一，發(fā)展簡(jiǎn)史第一階段：1945年至1951年，發(fā)明了核磁共振并奠定了理論和實(shí)驗(yàn)基礎(chǔ)的時(shí)期：布洛赫（斯坦福大學(xué)，在水質(zhì)子信號(hào)中觀察到）和賽爾（哈佛大學(xué)，第二階段：1951年至1960年為發(fā)展時(shí)期，其作用已被化學(xué)家和生物學(xué)家所認(rèn)可，解決了許多重要問題。 1953年出現(xiàn)在第一臺(tái)30MHz核磁共振光譜儀中； 1958年及早期出現(xiàn)了60MHz，100MHz儀器。 1950年代中期，發(fā)展了1H-NMR，19F-NMR和31P-NMR。第三階段：60-70年，NMR技術(shù)的跨越期。脈沖傅立葉變換技術(shù)提高了靈敏度和分辨率，可常規(guī)測(cè)量13C核；雙頻和多頻共振技術(shù)；第四階段：1970年代后期理論和技術(shù)發(fā)展成熟。1200、300、500、500 MHz和600 MHz超導(dǎo)NMR光譜儀； 2，各種脈沖系列的應(yīng)用，在應(yīng)用中變得重要發(fā)展； 3，二維核磁共振的出現(xiàn)； 4，多核研究，可應(yīng)用于所有磁芯； 5，出現(xiàn)了“核磁共振成像技術(shù)”等新的分支學(xué)科。二，主要目的：1。確定并確認(rèn)結(jié)構(gòu)，有時(shí)可以確定構(gòu)型，構(gòu)型2?；衔锛兌葯z查，靈敏度更薄，紙色譜法高3?；旌衔锓治?，如主要信號(hào)不重疊，無需分離即可確定混合物的比例。4。質(zhì)子交換，單鍵的旋轉(zhuǎn)，環(huán)的轉(zhuǎn)變和其他化學(xué)變化以推定速度1。原子核的自旋在所有元素的同位素中，大約一半的原子核具有自旋運(yùn)動(dòng)。這些自旋核是核磁共振的對(duì)象。自旋量子：描述原子核自旋運(yùn)動(dòng)的量子數(shù)，可以是整數(shù)，半整數(shù)或零。在有機(jī)化合物組成元素中，C，H，O，N是最重要的元素。在其同位素中，12C，16O是非磁性的，因此不會(huì)發(fā)生核磁共振。 1H自然豐度大，磁性強(qiáng)，易于確定，因此NMR研究主要針對(duì)質(zhì)子。 13C的豐度很小，只有12C的1.1%，而且信號(hào)靈敏度僅為質(zhì)子的1/64。因此總靈敏度僅為1H的1/6000，較難確定。但是在過去的30年中，核磁共振儀得到了很大的改進(jìn)，可以在短時(shí)間內(nèi)測(cè)量13C光譜，并給出更多的信息，已成為NMR的主要手段。 1H，19F，31P的自然豐度大，磁性強(qiáng)，且核電荷呈球形分布，最容易確定； 2。核磁共振現(xiàn)象①進(jìn)動(dòng)：具有一定的磁矩自旋在外部磁場(chǎng)H0的作用下，該鐵心將形成運(yùn)動(dòng)角：進(jìn)動(dòng)運(yùn)動(dòng)速度，與H0（外部磁場(chǎng)強(qiáng)度）成正比。②自旋核在外部磁場(chǎng)中的取向：無外部磁場(chǎng)時(shí)，自旋磁取向是混沌的。磁芯處于外部磁場(chǎng)H0中，方向?yàn)椋?I +1）。磁芯在外部磁場(chǎng)中的自旋可以類似于陀螺儀在重力場(chǎng)中的進(jìn)動(dòng)（旋進(jìn)，擺動(dòng)）。③核磁共振的條件磁共振磁場(chǎng)必須具有磁核，外部磁場(chǎng)和射頻磁場(chǎng)。 RF磁場(chǎng)的頻率等于自旋核的進(jìn)動(dòng)頻率，并且共振從低能態(tài)發(fā)生到高能態(tài)。④核磁共振現(xiàn)象：在外部磁場(chǎng)H0的垂直方向上，旋進(jìn)磁場(chǎng)H1被施加到進(jìn)動(dòng)核。如果H1的旋轉(zhuǎn)頻率等于原子核的旋轉(zhuǎn)進(jìn)動(dòng)頻率，則進(jìn)動(dòng)核可以吸收H1的能量并從低能態(tài)轉(zhuǎn)變?yōu)楦吣軕B(tài)。飽和和弛豫低能核比高能核僅高0.001%。因此，低能態(tài)核總是比高能核更多，因?yàn)檫@樣的一點(diǎn)剩余，所以可以觀察到電磁波的吸收。如果核連續(xù)吸收電磁波，則原來的低能態(tài)逐漸減小，吸收信號(hào)的強(qiáng)度會(huì)減弱，最終完全消失，這種現(xiàn)象稱為飽和。當(dāng)發(fā)生飽和時(shí)，處于兩種自旋狀態(tài)的核數(shù)完全相同。在外部磁場(chǎng)中，低能核通常比高能態(tài)具有更多的核，吸收電磁波能量并遷移到核心的高能態(tài)將通過多種能量機(jī)制釋放出來，并且回到原始的低能量狀態(tài)，這個(gè)過程稱為松弛。4。屏蔽效應(yīng)–化學(xué)位移①理想的共振狀態(tài)對(duì)于孤立的裸核，ΔE=（h /2π）γ·H；在一定H0下，一個(gè)原子核只有一個(gè)ΔEΔE= E之外=hν唯一的吸收頻率ν例如H0 = 2.3500 T，1H的吸收頻率為100 MHz，13C的吸收頻率為25.2MHz②②真正的核：屏蔽現(xiàn)象電子外的核（未隔離，未暴露）在化合物中：原子間的鍵合（作用）不同，例如化學(xué)鍵，氫鍵想象一下，靜電相互作用，分子間作用力想象：在H0 = 2.3500 T時(shí)，由于屏蔽層的外部電子，在核位置，實(shí)際磁場(chǎng)略小于2.3500 TR。聲子頻率略高于100 MHz多少？ 1H是0到10，13C是0到250氫核在外面有電子，它們排斥磁場(chǎng)的磁力線。對(duì)于原子核，周圍的電子被屏蔽（Shielding）效應(yīng)。圍繞芯的電子云的密度越大，屏蔽效果越好，相應(yīng)的磁場(chǎng)強(qiáng)度也會(huì)增加，從而使其共振。原子核周圍的電子云密度受連接基團(tuán)的影響，因此不同化學(xué)環(huán)境的原子核受到不同的屏蔽作用，其核磁共振信號(hào)也出現(xiàn)在不同的位置。③如果儀器以60MHz或在100MHz儀器中，有機(jī)化合物質(zhì)子的電磁波頻率約為1000Hz或1700Hz。在確定結(jié)構(gòu)時(shí)，需要確定正確的諧振頻率，通常需要幾個(gè)Hz的精度，通常以適當(dāng)?shù)幕衔餅闃?biāo)準(zhǔn)來確定相對(duì)頻率。標(biāo)準(zhǔn)化合物的共振頻率與質(zhì)子的共振頻率之差稱為化學(xué)位移5。 1 H NMR光譜信息信號(hào)數(shù)量：分子中存在多少種不同類型的質(zhì)子信號(hào)的位置：每個(gè)質(zhì)子的電子環(huán)境，化學(xué)位移信號(hào)強(qiáng)度：每個(gè)質(zhì)子的數(shù)量或數(shù)量分裂情況：多少存在不同的質(zhì)子常見類型的有機(jī)化合物的化學(xué)位移①誘導(dǎo)作用②共軛效應(yīng)由于π電子的位移，質(zhì)子屏蔽會(huì)減弱或增強(qiáng)共軛作用③各向異性效應(yīng)很難解釋H相對(duì)于π電子的化學(xué)位移，并且很難解釋電負(fù)性④H鍵效應(yīng)ROH，RNH2在0.5-5，ArOH在4-7，變化范圍，許多因素的影響；氫鍵隨溫度，溶劑，濃度的變化明顯，可以了解與氫鍵有關(guān)的結(jié)構(gòu)和變化。⑤溶劑作用苯與DMF形成配合物。苯環(huán)的電子云吸引DMF的正極，而拒絕負(fù)極。 α甲基在屏蔽區(qū)，共振移向高場(chǎng)； β甲基位于掩蔽區(qū)域，共振吸收向低電場(chǎng)移動(dòng)，其結(jié)果是兩個(gè)吸收峰的位置互換。
資料來源：Meeyou Carbide