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采用超重力场反应熔铸技术制备出(Ti,W,Cr)B2-(Ti,W,Cr)C复相陶瓷刀具材料,研究了W-Cr-Ni对材料制备过程的影响。XRD、FESEM与EDS分析表明,陶瓷基体主要由(Ti,W,Cr)B2四方晶、不规则(Ti,W,Cr)C、Al Ni及残余的Al2O3构成。随着W-Cr-Ni含量的增加,(Ti,W,Cr)B2与(Ti,Cr,W)C尺寸呈先增大后减小趋势。燃烧反应速率和熔体分离速率随W-Cr-Ni含量的增加而逐渐增大,而残留的Al2O3则逐渐减少。在冷却凝固过程中,Ti C与Ti B2先后形核析出,在其长大过程中,[W]、[Cr]原子取代部分[Ti],扩散至Ti C与Ti B2中,生成(Ti,W,Cr)C与(Ti,W,Cr)B2。随着W-Cr-Ni逐渐增加,[Ti]、[B]、[C]原子扩散距离逐渐增大,[W]、[Cr]扩散至(Ti,W,Cr)B2与(Ti,W,Cr)C晶体内部的含量也逐渐增大。在凝固后期,[Ni]与少量未反应的[Al]反应生成Al Ni,分布于基体间,提高了陶瓷的致密性。
The (Ti, W, Cr) B2- (Ti, W, Cr) C multi-phase ceramic tool material was prepared by super gravity field reaction casting technology and the effect of W-Cr-Ni on the material preparation was studied. XRD, FESEM and EDS analysis showed that the ceramic matrix mainly consists of tetragonal (Ti, W, Cr) B2, irregular (Ti, W, Cr) C, Al Ni and residual Al2O3. With the increase of W-Cr-Ni content, the sizes of (Ti, W, Cr) B2 and (Ti, Cr, W) C first increase and then decrease. The combustion reaction rate and melt separation rate increased with the increase of W-Cr-Ni content, while the residual Al2O3 gradually decreased. During the process of cooling and solidification, TiC and TiB2 nucleate and precipitate successively. During their growth, [W] and [Cr] atoms replace part of [Ti] and diffuse into TiC and TiB2 to form (Ti, W, Cr) C and (Ti, W, Cr) B2. With the increase of W-Cr-Ni, the diffusion distance of [Ti], [B] and [C] atoms gradually increases and [W] and [Cr] , Cr) C crystal content within the gradual increase. In the late stage of solidification, [Ni] reacts with a small amount of unreacted [Al] to form Al Ni, which distributes between the matrix and improves the densification of the ceramic.