Improve the quality of diamond tool from the process aspect.
* : * : admin * : 2017-11-09 * : 63
Findings shows, China stone, stone export volume and total output of stone consumption reached the first place in the world: stone processing enterprises2thousand, from personnel of course of study nearly5000000, with an annual output of6000000 cubic meters of stone, sheet metal with an annual output of120000000square meters, annual output value of more than 80000000000 yuan, has advanced more than 500 production lines, import and export a total of more than $1200000000, become the stone production big country live up to one's name.
Our country is a big country of ceramic production of all types of ceramic tiles, in 1999total output of 1600000000 square meters ( for33.6% of world total output ), the total consumption of 1300000000square meters ( for total world consumption of30.8% ). While the diamond and diamond tool manufacturers have more than 1000, with an annual output of more than750000000 carat diamond in 1999already, become a big producer. Diamond saw blade has been able to meet the domestic demand. Nearly 1/3 of exports, in the DIY market competitive strength.
China in the above-mentioned aspects have great power, but still not be powerful nation. With the global economic integration, China's entry into WTO, how to make our country become the production of diamond tools of power, which is placed in front of the Chinese counterparts in an important task. On the basis of our practice and investigation, only to improve the quality of diamond tool problems, put forward some views. ?
1 for the manufacture of diamond tools with mass production of stable performance, coarse particles, good thermal stability and high strength diamond
The quality of diamond quality, particle size and concentration on the diamond tool has a decisive role. Our country on diamond synthesis, the top six small tonnage, high technology has become mature, the top six large tonnage and large cavity continuous improvement process, top two synthetic diamond has also begun to take shape, powder catalyst synthesis, carbon leaf wax stones, raw materials for the production of continuous improvement. Therefore, in view of our country manufacturing of diamond tools, batch synthesis of stable performance, coarse particles, good thermal stability performance of high strength diamond is completely possible. The foreign diamond company, in addition to launch SDA+, SDB, DSN, MBS, ISD series, DeBeers for the China market launch of BKI, BK30, BK60, BK70 diamond, South Korea and Japan into the company launched the top six synthetic SDS series diamond, are worthy of our reference. ?
2with strong carbide forming elements, improve the diamond retention
To improve cutting efficiency and service life of diamond saw blade is a key factor for improving matrix on the durability of diamond. Matrix for diamond has good holding force, diamond will not prematurely detached, and with the greatest of protruding height, cutting sharp, high efficiency.
Improve the diamond retention generally has the following three kinds of methods:
(1) to improve the mechanical holding force. This is because the metal powder during sintering shrinkage, form a compressive stress holding diamond. Compression stress is produced by the diamond and the matrix metal with different coefficients of thermal expansion due to sintering, or crystal formation and growth caused by volume change caused by. As the carcass yield strength is limited, so the resulting compression stress and mechanical holding force limited.
(2) powder and adding a small amount of strong carbide forming elements such as Cr, W, Mo, due to its effect on Diamond wettability and good affinity, sintering in the diamond and the matrix metal is formed at the interface of carbide on diamond, gold combination, which is beneficial to control force to strengthen and improve.
Diamond (3) surface is coated with a layer of strong carbide forming metal elements such as Cr, Ni, Ti, W etc.. This is in last few years more adopted technology measures. For the Yanshan University specializes in the development and production of three models of vacuum micro-evaporation Ti coating equipment. ?
According to the domestic and foreign experimental research and that the use of diamond coating technology, the effective use of conditions and scope:
①suitable for high grade diamond, the effect is more obvious;
② in drilling in the matrix to control power order is: Cr > Ti > no plating plating plated diamond.
③ MBS-960Cr2chrome diamond applicable to Co matrix, WC matrix and lower Fe bronze matrix.
④ MBS-960Ti2Ti-coated diamond for drilling bronze matrix, iron-based matrix.
In cutting the asphalt, concrete curing ( GreenConcrete ) and enhanced ( reinforced ) concrete used in plating of diamond saw blade.
The nickel plated diamond for resin bonded grinding wheel, its use effect as follows: needle shaped nickel nickel plated diamond diamond > > without nickel plating of diamond.
The silver plated diamond is suitable for grinding tungsten carbide tools used in precision of resin bonded grinding wheel. Because the silver price is not very expensive, is suitable for high precision grinding, its thermal performance is good, suitable for grinding hard alloy oil cooler. While silver is a very good lubricant, reducing the friction between wheel and workpiece, the heat is not.
Coated with strong carbide forming elements Ti, Ni, W, Cr and so improve the diamond retention, mainly due to:
①metal coating can prevent the diamond in a certain temperature, pressure and sintering time under oxidizing conditions, graphite and iron hot corrosion resistance. The author of different metal plating diamond TG ( TG ) analysis, found the diamond in 800℃begins to weightlessness and graphitization. While the plating Ti, W, TiN and diamond were at 900 ℃,925 ℃and940 ℃to weightlessness and graphitization. Description of diamond plated metal is benefit to prevent oxidation and graphitization, can withstand the thermal shock and thermal decomposition. On high temperature sintered matrix has obvious protective effect.
②plated strong carbide forming element in the sintering conditions on diamond and the matrix interface formation carbide alloy, is conducive to the diamond and the matrix metal chemical bonding and metallurgy combination, greatly improving carcass on the durability of diamond, the tungsten plating diamond X ray analysis, now has formed the WC diamond surface.
③can improve the diamond static strength5%～ 20%.
The diamond plated metal, can improve the diamond friction, which helps to increase the holding force.
3 the superfine powder and pre alloyed powder
In the production of diamond saw blade for cutting, should adopt the ultrafine metal powder and pre alloyed powder. Metal powder refinement is beneficial to reduce the sintering temperature, improve the hardness. Pre alloyed powder, can prevent the low melting point metal premature loss and segregation, in favor of sintered products elastic limit and yield strength, to increase the durability of diamond, but also can reduce the sintering temperature and heat preservation time. China's Shanghai Research Institute of materials, Beijing artificial crystal, Changsha Metallurgical Materials by powder metallurgy and South University have made great efforts in this respect. Korea in high-grade production of saw blade, the wide use of BASF, UM, INCO, Fum-tungstene, Kennametal companies such as ultra-fine powder and pre alloy powder. ?
4in the cutter head to promote granulation process in production of
Granulation process in our country hard alloy, ceramic production has been widely used in recent years, the diamond cutter head production also obtained the widespread application and the development. Powder granulating the advantages, diamond segregation decreases, more uniform distribution, improve the cutting performance, increase the fluidity of powders, so that the volume of cold pressing application possible, common cold press process better, reduce the harm of dust on workers. Its disadvantage is the increased investment and technology program, granulation to binder, the latter on the welding, sintering and carcass performance may have adverse effects.
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