TC17粉末钛合金HIP/IF复合工艺制备及组织性能演变

Preparation and Microstructure as well as Property of TC17 Powder Alloy by HIP/IF Process

摘要:

采用粉末热等静压(HIP)＋等温锻造(IF)的复合工艺制备TC17粉末钛合金，并分析研究工艺过程中合金组织和性能的变化。结果表明：粒度<104 μm的雾化TC17合金粉末经热等静压后，合金成分均匀，显微组织为细针状的魏氏组织，室温抗拉强度为1210 MPa、延伸率仅为4%；经高低温慢速等温锻造后，合金密度得到进一步提高(99.9%)，显微组织中的原始β晶粒得到完全破碎，获得了细小的等轴晶粒；固溶时效热处理后，大量等轴α相均匀地弥散分布于β转变基体上，α相尺寸很小，约1~2 μm。最终粉末合金室温抗拉强度为

Abstract:

A technology combining hot isostatic pressing (HIP) with isothermal forging (IF) was used to prepare TC17 powder alloy, and the changes of its microstructure and properties were also researched and analyzed. The results indicated that the powder alloy prepared by HIP of atomized TC17 powder with particle size <104 μm exhibited a homogeneous chemical composition and a fine acicular Widmanst?tten microstructure, and the tensile strength at room temperature (RT) was 1210 MPa, the elongation only 4%. After low-velocity IF at high and low temperature, the density of the powder alloy was further improved (99.9%), and primary β grains were broken completely, resulting in gaining fine and equiaxed grains. After solution aging heat-treatment, much equiaxed α phases distributed around transformed β matrix evenly, and their size was 1~2 μm. Finally, the powder alloy exhibited tensile strength of 1210 MPa at RT and elongation of 16%, and the strength and plasticity were matched excellently and exceeded technical demands for more.