预合金粉对金刚石复合体组织结构影响及机理分析

Effect and mechanism of pre-alloy powder on microstructure of diamond composite

关键词:  预合金粉  金刚石复合体  胎体性能  组织结构

Key words:  pre-alloy powder  diamond composite  matrix properties  microstructure

摘要:

文中以热压烧结金刚石刀头胎体材料为研究对象,对比分析了添加不同比例的FCu14预合金粉对金刚石刀头孔隙率、硬度、抗剪强度、抗弯强度等性能的影响.结果表明,随着FCu14预合金粉含量的增加,胎体合金成分均匀化,微细的铁基胎体被铜基粘结相均匀地包围,减少了孔隙的存在.胎体的孔隙率明显降低,孔隙均匀细小,因而金刚石刀头胎体硬度逐渐升高.胎体孔隙率的降低使得孔隙率对材料基体的割裂作用降低,相应的材料中的微观缺陷也就越少,从而使得其抗剪强度和抗弯强度提高.但加入量过高会使胎体硬度增加过大,导致胎体的韧性大幅度下降,脆性显著增加,脆性的增加会使得断口中韧窝的数量急剧减少,其相应的强度就会降低.

Abstract:

With matrix materials for hot pressing sintered diamond segment as the object in this study, the authors analyzed the effect of FCu14 pre-alloy powder on the performances of diamond segment from different formulation. The results showed that, with the increase of FCu14 pre-alloy powder content,matrix alloy composition gradually becomes uniform. Tiny iron-based matrix is surrouded evenly by copper-based binder, reducing the presence of pores. Because porosity of matrix significantly uniform and refinement, porosity was reduced greatly, the matrix hardness gradually increased. A decreasing of porosity makes the fragmentation of it on matrix reduction. The corresponding microdefect in material is also little, making the shear strength and bending strength increased. However, excessive dosage will make the matrix too large, resulting in significant decline in the toughness of the matrix and an increase in brittle, that will make the number of dimples in the fracture decreased rapidly. So its strength will be reduced accordingly.