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Notice of the essay on the twelfth national hard alloy academic conference (first round)
To show China's cemented carbide industry in technological innovation, scientific and technological progress and industrial upgrading of glorious achievements, in-depth exchanges carbide and new materials, new technology and new technology in the areas of results and related information, promoting progress and development of Chinese cemented carbide industry, enhance China's cemented carbide products in the international market competitiveness, to March 23 ~ 25, 2018, held in Shanghai "the 12th national carbide academic conference". The details of the collection are hereby notified as follows:
- I. conference theme
- China's hard alloy independent innovation and industrial upgrading Ii. Host organization
- China tungsten industry association cemented carbide branch Hard alloy state key laboratory
- China tungsten industry association cemented carbide branch The hard - and - gold state home retest
Scope of article
- 1. New technologies, new technologies, new theories, new materials, new equipment and other research achievements and applications of hard alloys
- 2. Theoretical research and practice of resource utilization, green manufacturing, energy conservation and emission reduction, etc
- 3. Introduction of advanced technology and equipment, digestion and absorption and application
- 4. Application of industrial automation and intelligent manufacturing in hard alloy industry
- 5. Analysis and testing of hard alloy, new instruments and applications
- 6. Development review of hard alloy industry at home and abroad
- 7. Experience and achievements of hard alloy market analysis, technological transformation and industrial upgrading
- 8. Other research reports on enterprise development and technological innovation
Type of molding agent for hard alloy production
The total carbon content of the alloy must be strictly controlled by the production of high quality hard alloy products. Alloy in the total carbon content is too high, easy to produce graphite phase in the alloy, and the total carbon content is low, easy to produce the brittleness eta phase, in the many factors influencing the carbide content, forming agent is an important aspect.
The production of cemented carbide is divided into three categories:
The first category is a synthetic rubber (including the modified rubber) as the representative of forming agent, its characteristic is good formability, high compact strength, can suppress a shape more complex and bulky products, rubber in the sintering process, removal is weakness due to thermal cracking for sintered body more free carbon residue, and the content is not stable, the precise control of alloy carbon bring considerable difficulties
The second type is a delegate with paraffin is forming agent, due to its high cracking temperature, in the form of a gas when heated to removal without the pressure cracking occurs in the block, so almost no carbon residue, this for the production of high quality hard alloy products is quite important. In addition, paraffin wax is not "ageing" compared to rubber, and there is almost no ash, which does not bring impurities into the alloy. The weakness of paraffin wax is low viscosity, poor forming and low pressure.
The third type of forming agent is water-soluble polymer PEG (polyethylene glycol), which has hydrogen bond polarity, and the lower molecular weight is stronger, and it has better compatibility with many substances. The stickiness of PEG is between rubber and paraffin, which is related to its molecular weight. Similar to rubber, PEG can be pyrolytic and residual free carbon during heat removal. In addition, the PEG has strong moisture absorption, moisture absorption of powder material to harden, pressing pressure, forming for complex product is difficult, at the same time, the presence of water on the alloy precision control carbon also difficult.
In terms of preparation of high performance cemented carbide, paraffin wax has a great advantage. It is also a kind of molding agent commonly used at home and abroad.
The patent work in China's hard alloy industry has changed rapidly from scratch, hunan CNC blade
The industrial chain of hard alloy is longer, which can achieve greater value added space from the original tungsten mine to the final hard alloy and its products industry chain. Preliminary estimation, from the original raw material fine mineral powder into metal powder, product value increased by about 3 times; From fine mineral powder to common cemented carbide, it can increase the value of product by about 6 times. From fine mineral powder to CNC lathe rotary blade, the product more than 20 times.
China's hard alloy industry started in the 1950s and has gone through nearly 60 years of development of technology introduction, digestion and absorption and independent innovation. Domestic hard alloy enterprises have grown and grown, and have made great progress in both quantity, scale and technology. Along with the development of the market through early in vulgar, cemented carbide enterprises gradually attaches great importance to the research and development innovation ability, to enhance consciousness of protection of intellectual property rights, the patent of cemented carbide industry work from scratch, development and change very quickly. At present, more than 30 universities and research institutes in China are engaged in the research of hard alloy, and the proportion of technical personnel is about 10%.
According to the patent application data of cemented carbide industry, the growth of new patent growth in the hard alloy industry in 2006 has been increasing rapidly and reached its peak in 2014. In 2006, the number of new patents for hard alloys in China was just 169, and by 2014 the number of new patents had reached 661.
Progress of super hard materials in China
New progress in the raw material of the binder
1. Ultrafine iron powder
Refine the granularity of metal powder for activation sintering temperature and sintering, to reduce the products improve the bond strength of the holding of the diamond, improve the machining efficiency of products, service life plays an important role. The carbonyl iron powder has been applied, but its cost is still high, and the application of some heavy efficiency demands is not very economical. The occurrence of ultrafine iron powder solves this problem, and the ferric particle size of the iron powder reaches 1. 8-2. 0 microns, the sintering temperature below 900 ℃.
2. Pre-alloy powder
Metal powder alloying beforehand to prevent metal bond products in premature sintering process in low melting point metal loss and segregation, improve the density of sintered products, uniformity, elastic limit, and the yield strength, enhance the control ability of diamond, and reduce the sintering temperature. In recent years, metal powder prealloying technology has attracted attention. For example, the use of Cu - Zn - Ni and Cu - Ni - Mn prealloy powder is made of geological diamond bit, its service life and machining efficiency are 99% and 45% higher than non-prealloy powder bit, and the effect is obvious.
3. Super thin toughened polyimide tree powder
Than polyimide resin and phenolic resin, high bonding strength, high heat resistance temperature 50 ℃ (above), under the condition of dry grinding wheel life is more than double. However, polyimide resin has poor toughness, low bending strength and high cost, which limits its application to a certain extent. To change this situation, developed a 30-40 microns average particle size, curing temperature 230 ℃, after toughening modification of ultrafine powder toughening polyimide tree, compared with common polyimide resin, its bending strength increased by 23%, the compressive strength increased by 20%.
New progress in the research of binding agent
1. Ceramic binding agent
Low temperature sintering and high strength ceramic binding agent have been one of the main themes in the industry.
(1) the ceramic binding agent applied to 80m/sCBN grinding wheel has been put into practice;
(2) the ceramic binder used in 120m/sCBN grinding wheel has been developed successfully;
(3) ceramic bonded grinding tools used in hard alloy tools, diamond composites, magnetic materials and engineering ceramics are also developed successfully.
(4) in order to give full play to the advantages of ceramic binder with stomata, the control of stomata is realized, and the influence of hole - making agent on ceramic binder can be studied. The study shows that the strength of the abrasive with graphite is affected by the shape of graphite particles, the amount of addition and the sintering temperature, and the strength of the abrasive has decreased with the increase of the amount of the addition. And add CaC03 of grinding tool with high intensity, generate stomatal shape more spherical, uniform distribution, the allowed range increased with the increase of the content of stomatal size, pore effect of CaCO3 is better than graphite.
2. Sintered metal binding agent
The research of "iron cobalt" is another hot spot in China's diamond tool research. In recent years, the application of rare earth element La and Ce has been concerned in order to improve the performance of iron base binding agent. Doped method of adding rare earth elements of research shows that: using the method developed by iron fund corundum tool, the bending strength, impact toughness, hardness and porosity, and other four indicators is close to or slightly more than without corresponding index of the rare earth cobalt fund corundum tool. The study of rare earth elements in the form of rare earth materials showed that the flexural strength and impact toughness of the matrix were improved by 12. 4% and 16. 6%, and hardness only increases by
3. The microstructure of the microstructure is obviously refined, the matrix is more closely combined with diamond, the diamond blade height is greatly increased, and the service life is increased by more than 24%.
4. Electroplating metal binding agent
Like sintering metal bond, rare earth elements in the electroplating products are also cause for concern: the application of rare earth elements in the form of chloride in Ni, Co in the plating solution study, tire body made of material porosity decreased significantly, significantly higher hardness, coating dispersing ability increased by more than 12%, the deep plating ability increased by more than 20%, plating speed greatly improved. Meanwhile, the study of low-cobalt electroplating formula has also been made, and the study of Ni - Co - Mn as an alternative to Ni - Co indicates that the Co content in the plating solution has been reduced from 30% to 5% and added 0. 1% Mn, hardness and strength of the coating is higher than Ni, Co, toughness decreases obviously, the production of electroplated diamond tools used for carving more sharp than with Ni, Co, durable, and production costs down.