【摘要】 采用共沉淀法制备含有Co、Ni、Sn元素的Fe-Cu基预合金粉,在此预合金粉中添加25%(质量分数)的WC作为骨架相,在700~860℃温度下真空热压烧结,获得金刚石工具用金属结合剂。利用X射线衍射(XRD)和扫描电镜(SEM)对预合金粉末及金属结合剂进行形貌观察与物相分析,并测定烧结体的硬度、抗弯强度及磨耗比等力学性能。结果表明,Fe-Cu基预合金粉已形成固溶体,实现了合金化,粉末粒度较细,约在3μm左右,表面较光滑,呈不规则状。Fe-Cu基预合金粉末的原子扩散及相变主要发生在820~846℃温度范围内,在820℃下热压烧结时效果最好,胎体孔洞缺陷少,具有最佳的物理与力学性能,硬度为113.9HRB,致密度达到98.86%,抗弯强度为1 306.4 MPa,结合剂对金刚石颗粒的包镶能力最强。更多还原

【Abstract】 Fe-Cu based pre-alloyed powder containing Co, Ni and Sn elements was manufactured by co-precipitation method. Metal bond used for diamond tools were fabricated by vacuum hot press sintering Fe-Cu based pre-alloyed powder with adding mass fraction of 25% WC as skeleton phase under the temperatures of 700 to 860 ℃. Phase composition and morphology of pre-alloyed powder and metal bond were characterized by XRD and SEM. Mechanical properties including hardness, bend strength and abrasion ratio of the sintered matrix were also studied. The results show that solid solution has formed in the pre-alloyed powder owning solid solution phase with fine particle size of about 3μm, smooth surface and irregular shape was obtained. DSC curve show that the atom diffusion and phase transformation undergo in 820~846 ℃. The matrix has little pore defect and optimal physical and mechanical properties when sintered at 820 ℃. The hardness is 113.9 HRB,relative density is 98.86% and bend strength is 1 306.4 MPa. Meanwhile the bond force for diamond of the metal bond sintered at 820 ℃ reaches the maximum value.更多还原