挤压比对粉末包套热挤压致密W-40%Cu合金的影响

采用不同挤压比对W-40%Cu混合粉末进行粉末包套热挤压,获得了W-40%Cu合金。研究了模具总挤压比λ对热挤压坯料致密化以及组织性能的影响。结果表明,随着挤压比的增加,热挤压坯料的相对密度也增加,同时电导率和硬度值也随之提高。由于含铜量比较高(质量分数为40%),即便在挤压比为25时,挤压坯内部W相也不发生变形,主要是铜相产生变形。进一步将模具总挤压比λ细分为不考虑体积变形的坯料总挤压比α,除去体积变形因素的坯料塑性挤压比β以及包套挤压比γ三种实际挤压比,分析了不同挤压比对热挤压致密化过程的影响。

The Influence of Extrusion Ratio on W-40 % Cu Alloy Produced by Powder Canning Hot Extrusion

W-40 wt.%Cu alloys with different extrusion ratio have been obtained by powder canning hot extrusion. The experimental results show that, the relative density, specific conductance and hardness of the billets increase with the adding extrusion ratio. There is no shape change of W phase after powder canning hot extrusion even if the extrusion ratio is up to 25 due to high content of Cu phase （40 wt.%）. The deformation mainly occurs in Cu phase. The total extrusion ratio （k） is divided into three kinds of actual extrusion ratio： the extrusion ratio of billet （ct） without considering the volumetric deformation; the plastic extrusion ratio （6） excluding the influence of volumetric deformation; the extrusion ratio of can （~）. This article studies the influence of these three kinds of actual extrusion ratio on the densification of W-40 wt.% Cu alloy by powder canning hot extrusion.