金刚石工具用FeCoCu预合金粉组成对烧结特性的影响

Effect of composition of FeCoCu pre-alloyed powders on sintering characters used for diamond tools

通过共沉淀法制备不同Fe-Cu配比的FeCoCu预合金粉,并对其微观结构进行表征与分析。同时,对3种粉体进行不同温度下的烧结实验和对烧结试样块进行力学性能及磨损质量损失进行测试,并对预合金粉与金刚石的界面结合情况进行探讨。结果表明:预合金粉中形成了Co_3Fe_7、CoFe_(15.7)、FeCu_4等中间相,在一定程度上实现合金化。3种预合金粉末的形状均为不规则状,粉末颗粒较细,且相互连接,表面疏松,有利于烧结。3种预合金粉中单质相仍占有较大比例,单质配比对烧结体性能有重要影响。Fe含量增加时,试样的理想烧结温度及烧结体力学性能均升高。Fe-Cu配比会对微观结构产生重要影响,胎体对金刚石以机械包镶为主,结合XRD及Raman光谱可知,与预合金粉烧结后的金刚石表面发生石墨化。

The FeCoCu pre-alloyed powders were manufactured by co-precipitation method.The microstructure was characterized,the sintering experiments were carried out,the mechanical properties and wear loss were tested and the combination condition between diamond and the powders was analyzed.The results show that the mesophases,such as Co_3Fe_7,CoFe_(15.7) and FeCu_4,are formulated in the three powders,and all the powders have irregular shapes,interconnected fine particles and large surface areas.Although the solid solutions are formed,the sintering,mechanical properties and mass loss of the three powders are based on the Fe-Cu ratios.With Fe content increasing,the ideal sintering temperatures,hardness and three point bend strength raise.The relative density decreases,the wear loss becomes better.Fe-Cu ratio has important influence on the powders microstructure.The mechanical retention is the main strength in the matrix and graphitization has occurred in the diamond surface after sintering with the FeCoCu pre-alloyed powders.