Experimental Study on Improving the Reliability of Cemented Carbide Tools

Super coarse grained cemented carbide with high fracture toughness and red hardness, better thermal fatigue and thermal shock resistance, is a kind of new type alloy performance, can be used in the production of oil drilling, coal cutter tooth, cold pavement milling planer tooth, stamping die, etc., can well meet the demand of the continuous operation of extreme operating conditions. At present, the domestic advanced level of the coarse grain of hard jin jing granularity can be up to 6 microns, the foreign advanced level of 10 microns. Super coarse grained cemented carbide tungsten carbide powder, raw material in to improve the quality of super coarse grained cemented carbide products, enlarging the application scope of super coarse grained cemented carbide, lengthen the service life of high wear-resistant cemented carbide tools and so on is of great significance.

 

Although in recent years a variety of new carbide cutting tool material emerge in endlessly, but in a long time in the future,carbide cutting tools will be widely used in machining, so need to research the development of new materials preparation technology, to further improve and improve the cutting performance of cemented carbide cutting tool materials.

 

By refining grain size of hard phase, increase hard phase bonding force between intergranular surface area, the increase of grain size, can make the strength of the cemented carbide cutting tool materials and wear resistance are improved. When WC grain size decrease below submicrometer, material hardness, toughness, strength, abrasion resistance and so on all can improve, achieve full densification required temperature can be reduced. Ordinary hard jin jing granularity for 3-5 microns, fine grain size of hard jin jing granularity for 1-1.5 microns (microns), ultrafine grain of hard jin jing particle size of 0.5 microns below (sub-micron and nanometer level).

 

Due to the grain refinement process method is still not enough mature, so in the process of the cemented carbide sintered nanometer grain growing easily into rough grain, the grain is generally grew up will be led to the decrease of the strength of materials, a single thick WC grain is often is the important factor causing the material fracture.