摘要
采用粉末冶金技术制备W-6Ni-4Co-2X(X=Nb、Ta、Hf、Mo、Ti)合金,研究添加Nb、Ta、Hf、Mo和Ti元素对W-6Ni-4Co合金组织和力学性能的影响.结果表明:W-6Ni-4Co-2X合金的显微组织主要由基体相(W相)和黏结相组成,且黏结相的种类和含量与烧结过程W相在黏结相(Ni,Co)中的溶解析出有关.W-6Ni-4Co-2Ta、W-6Ni-4Co-2Hf合金组织W晶粒呈不规则多边形,W-6Ni-4Co-2Nb、W-6Ni-4Co-2Ti合金组织W晶粒呈椭球形,并分散分布在黏结相中.W-6Ni-4Co-2Ta合金组织均匀、晶粒细小、W/黏结相界面结合良好,使其硬度、抗弯强度和屈服强度较高.W-6Ni-4Co-2Mo合金组织W晶粒呈网状排列,连续W骨架结构与延性黏结相协同降低了合金的应变硬化程度,使其具有较好的抗应变硬化性能.因此,向W-6Ni-4Co合金中添加合适的过渡金属元素是提高其力学性能的一种有效途径.
Abstract
The W-6Ni-4Co-2X alloys(X=Nb,Ta,Hf,Mo and Ti)were prepared by powder metallurgy technology,and the effects of adding Nb,Ta,Hf,Mo,and Ti elements on the microstructure and mechani-cal properties of W-6Ni-4Co alloy were investigated.The results show that the microstructure of the W-6Ni-4Co-2X alloys mainly includes base phase(W phase)and binder phase,and the type and content of the binder phase are related to the precipitation of dissolved W phase in the binder phase(Ni,Co)during sinte-ring.The W grains of W-6Ni-4Co-2Ta alloy and W-6Ni-4Co-2Hf alloy are in the form of irregular polygon,while the W grains of W-6Ni-4Co-2Nb alloy and W-6Ni-4Co-2Ti alloy are ellipsoidal and dispersedly dis-tributed in the binder phase.The uniform microstructure,finer grains,and good interfacial bonding of the W/binder phase in W-6Ni-4Co-2Ta alloy contribute to its superior hardness,bending strength,and yield strength.In W-6Ni-4Co-2Mo alloy,W grains are arranged in network structure,and the continuous W ske-leton structure,in synergy with the ductile binder phase,reduces the strain hardening of the alloy,contribu-ting to its excellent strain hardening resistance.Therefore,adding suitable transition metal elements to W-6Ni-4Co alloy provides an effective way for improving its mechanical properties.
基金项目
陕西省自然科学基础研究计划青年项目(2020JQ-870)
维普
万方数据