Study On Synthetize And Property Of High Toughness Polycrystalline Cubic Boron Nitride(PcBN) Compact

In this paper, Polycrystalline cubic boron nitride (PcBN) composite is synthesizedby adding binders to cBN powder under high pressure and temperature.Combiningagent is given priority to titanium alloys system and Ti (C, N)/Al metal ceramicsystem, while adding SiC whiskers of different surfactant treatment and rare earthoxides.the treatment of SiC whisker is vacuum plating titanium and chemical platingnickel. The purpose is to synthesize polycrystalline cubic boron nitride (PcBN)composite with high toughness to produce cutting tool by changing the combinationagent element.By reference to the domestic and foreign article about synthesis and preparation ofPcBN,based on my research results, this paper discusses influence factors of physicalperformance and machinability of PcBN tools.this paper optimizes the approach ofthe formula and synthesis process.Firstly,This paper studies the pure Binder in order to provide a reference for thesynthesis of the compact. That of titanium Alloy system binder,adding differentelements changes the comprehensive performance.W is optimal and Mo, Sifollowed by. Ni, Mn play a distinct role in changing the hardness of titanium binder.For Ti (C, N)/Al metal-ceramic bonding agents, aluminum content is the mostsignificant in changing its integrated performance. Al2O3, WC, and other hard phasedecrease the integrated performance of the binder.The impact of Si in its performanceis not obvious. the SiC whiskers deteriorats its performance seriously.Through the test of the abrasion,impact resistance, microhardness performancetesting of PcBN composite, and metallographic microscope, X-ray diffraction analysisand SEM etc analysis means，sure the optimal synthetic technology of PcBNcomposite.this paper discusses the influence on the performance of the compactadding the different components. For Ti and its alloys combination agent: adding W,Mo, Si elements remarkably enhance the comprehensive performance of the compact.Ni, Co reduces its performance insteadly. Mn improves the micro hardness ofcomposite. The synthesized compact of Ti+Al+Mo+Si, Ti+Al+W combinationagent in performance test is the best. It points out the importance of the a elements coefficient of linear expansion and crystal structure in the choice of combinationagent element. XRD analysis shows that, cBN and binder elements in hightemperature and high pressure condition have generated different objects. The impactof generated objects on performance of the compact is very obvious. For metalsceramic combination agent, Al is excellent performance additives, the content ofmetal Al is not less than30%of the binder to ensure the reactions.Rare earth oxides, chemical copperplating Ni SiC whisker improves thecomprehensive performance of the compacts, especially the impact resistance.