Influence of metal powder of the hottest ball mill

2022-08-14
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The influence of ball milling metal powder on the matrix of diamond saw blade

by means of sintering at a series of temperatures, hardness and bending strength, the information requirements of product identification are clarified, and the sintering process and performance test analysis of copper based and iron-based diamond saw blade matrix before and after ball milling are carried out. The results show that ball milling can broaden the sintering area, reduce the sintering temperature, improve the hardness and bending strength of the matrix, especially for iron-based matrix. This is related to the mechanical homogenization and refinement effect of ball milling powder on the matrix, which promotes diffusion sintering and homogenization from the surface

diamond saw blades have been widely used in the processing of stone, glass, ceramics and other materials, as well as the construction of houses, roads, bridges and other projects. With the continuous progress of diamond saw blade manufacturing technology and the continuous reduction of cost, its application field is still expanding, and the demand continues to increase. In recent decades, due to the super hard sawing and grinding performance of diamond tools, the diamond tool industry has flourished

the working part of diamond saw blade is sawtooth (also known as cutter head). The cutter head is formed by sintering after mixing a certain proportion of diamond and a certain proportion of metal powder (metal binder is also called matrix). When working, the diamond in the cutter head is carved into the cut material at high speed to break it. The surface binder plays the following important roles in the performance of diamond tools:

(1) disperse and control the diamond

(2) make the diamond have certain exposure, provide matching wear, and prevent the diamond from falling off prematurely

(3) when diamond impacts the workpiece, the bond bears and disperses the impact and load generated

(4) act as a radiator to quickly transmit the heat generated during operation

therefore, the design of bond system is a very important work in the design of diamond tools. General bonding system should meet the following requirements:

(1) have good bonding parts for diamond; In addition, there is no etching or only a slight picture of diamond. The project, which understands the "guide to the development of new materials industry", is carried out by alvant, a British aluminum matrix composite expert, together with Ge aviation, Yasa motors and the national composites center

(2) it has good hardness and strength, and its wear-resistant parts should adapt to the wear and self sharpening of diamond

(3) the hot pressing sintering temperature cannot be higher, and the sintering process is stable

the design of bond system is generally from the following two aspects

(1) formula, that is, the type and proportion of metal powder

(2) shape of metal powder, such as particle size (size), morphology, alloying degree, etc. Because ultra-fine powder and pre alloyed powder have the characteristics of low sintering temperature, wide process range, uniform structure, good oxidation resistance and good impregnation of diamond, they are very suitable for matrix materials of diamond tools. Therefore, matrix pre alloyed and ultra-fine have become the research and application hotspot of diamond tool industry in recent years

at present, the preparation methods of pre alloyed powder mainly include chemical precipitation method, atomization method and mechanical alloying method. Chemical precipitation method is to make metal powder according to the principle of hydrometallurgy, that is, prepare metal solution according to the designed ratio of Yi body, add precipitant, and strengthen the process to make all kinds of metals leave the precipitation surface almost at the same time to obtain sediment with uniform composition, and then heat the sediment to decompose, reduce, crush, screen and other processes to obtain the required powder. The utility model has the advantages that the powder with fine particle size and low porosity ratio equivalent to C0 powder can be prepared, which is very conducive to the sintering of tool bits. But the oxygen content is high, which pollutes the environment. In recent years, the atomization method is to melt a certain proportion of metal into an alloy first, and then inject it into a leaky bag. When the molten metal flows through the nozzle through the guide nozzle, it is broken into small droplets by the high-speed fluid emitted by the nozzle, which fall into water and solidify into powder. Its overall advantage is that the powder has high alloying degree, uniform composition and large production capacity. In recent years, some people have discussed and studied this aspect. The results show that pre alloying can reduce the sintering temperature of the matrix, homogenize the microstructure of the matrix, and improve the holding force of the matrix on Diamond. However, the disadvantages of atomization method are that the particle size is large, the distribution range is wide, and the median diameter of laser particle size is generally more than 209 m. The production process causes metal dust pollution. At present, under the current situation of mutual confidentiality of diamond tool production and food industry formulas, and their food industry scale is relatively small, atomization prealloying is difficult to promote, and most of the metal binders are still in the state of mechanical mixing at present; The mechanical alloying method is to carry out long-time ball milling in a high-energy ball mill according to a certain ball milling ratio. The powder is repeatedly extruded and crushed, and the microstructure is gradually refined to realize alloying in the solid state. This method is low-cost, pollution-free, simple and flexible, and small enterprises can do it by themselves. At present, there are few reports about mechanical alloying. This study aims to explore this aspect

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