镀膜金刚石在不同金属结合剂中的表现

制备8种不同的金属结合剂金刚石工具材料,研究表面镀膜的金刚石在不同结合剂中的表现.通过三点弯曲试验评价金刚石表面镀膜对抗弯强度的贡献,并借助扫描电子显微镜(Scanning electron microscope,SEM)和能谱分析仪(Energy dispersive spectrometer,EDS)分析,揭示金刚石与结合剂界面作用机制.通过锯切花岗石并在线测量锯切力和功率,研究金刚石表面镀膜对其耐磨性的影响.研究表明,镀膜对增强结合剂把持金刚石能力的贡献是肯定的,但是结合剂各金属组分间的结合对抗弯强度的影响大于结合剂与金刚石间的结合对抗弯强度的影响,因此对于不同的结合剂系统,金刚石节块的耐磨性能与其抗弯强度之间没有明确的对应关系.结合剂中的稀土添加剂以及基础结合剂中的主要成分直接影响镀膜金刚石的表现.

PERFORMANCE OF COATED DIAMONDS IN DIFFERENT METAL MATRICES

Eight metal-bonded diamond tooling materials are fabricated to evaluate the performance of coated diamonds in different metal matrices.The contribution of coatings to trans-verse rupture strength is assessed through three-point bending tests.Coupled with SEM and EDS analyses,the bonding be-tween diamonds and metal matrix is revealed.The effects of coatings to the wear performance of diamond segments are studied through circular sawing of granite and in-process monitoring of cutting forces and power in sawing.It is found that the coatings are positive to the increased retention of bond matrix to diamonds.It is difficult to establish a specific rela-tionship between the wear performance of the specimens and their transverse rupture strength if the bond system is different.However,the bonding among bond matrix components con-tributes more than the bonding between the bond matrix and diamonds.The performance of coatings depends not only on whether the matrix contains rare earth but also on the types of bond matrix.