两种模具材料对热等静压TC4显微组织的影响

Effect of Two Die Material on Microstructure of Hiped TC4 Alloy

研究了A3钢和GH1131高温合金两种材料作为模具对TC4钛合金HIP组织的影响。结果表明在HIP过程中,A3钢模具对有效应力传递的阻碍作用较大,设计HIP用A3钢模具时应避免深型腔结构,GH1131模具对有效应力传递的影响较小。受元素互扩散的影响,两种模具材料在HIP过程中均污染了TC4材料表面,A3钢模具对合金的影响层较薄,但使材料形成了波浪形的粗糙表面;GH1131对成形材料的影响层厚度>100μm。为了获得高精度的无污染表面,TC4合金HIP净成形时两种模具均需要进行表面处理,形成与TC4兼容的保护层。

The effect of mild-carbon steel and high-temperature alloy GH1131 on the microstructure of HIPed TC4 alloy was studied. The results show that mild-carbon steel die prevents the transfer of the stress for densification of TC4 during the process of HIP, different from the GH1131 die. When the die is designed ,the deep cavity structure should be avoided for the mild-carbon steel. Due to the interdiffusion of elements, the alloy surface is contaminated by both of the die materials. Although the thickness of the boundary between TC4 and mild-carbon steel is slim, the alloy surface is coarse with the wave-like morphology. And the thickness of the boundary between TC4 and GH1131 is raised to more than 100 μm. In order to gain the clean and smooth material surface, the die cavity surface must be treated to form a protect layer compatible with TC4.