激光烧结/等温锻造TC17粉末钛合金的组织与性能

Microstructures and Properties of TC17 Powder Metallurgy Titanium Alloy Prepared by Laser Sintering/Isothermal Forging

摘要:

采用激光烧结（LS）＋等温锻造复合工艺制备出优质粉末TC17钛合金材料，并研究了工艺过程对合金组织性能的影响。结果表明：激光烧结后的TC17合金微观组织主要由粗大β柱状晶粒组成；经相变点上、下等温锻造及热处理后，激光烧结的魏氏组织能够被有效地破碎，显微组织主要由条状和细小等轴α相组成；仅经相变点以下等温锻造及热处理后，合金组织主要由细小等轴α相组成，但由于变形不均，仍存在有少量的原始β晶粒边界。经过等温锻造、热处理后，激光烧结合金的室温强度变化不大，但塑性大大提高，强度和塑性得到了良好地匹配。

Abstract:

The laser sintering + isothermal forging technology was used to prepare excellent powder metallurgy TC17 titanium alloy, and the influence of technology on the microstructure and properties was investigated. The results indicated that the microstructure of laser sintered TC17 titanium alloy was comprised of coarse columnar β grains. After isothermal forging up and below β transus, followed by heat treatment, laser sintered Widmanst?tten structure was broken effectively, and transformed into plate, fine and equiaxed α phase. Only adopting isothermal forging below β transus and heat treatment, the microstructure consisted mainly of fine and equiaxed α phase, but little amount of primary β grain boundary was still remained owing to uniform deformation. After isothermal forging and heat treatment, the plasticity of the alloy at room temperature was increased obviously with little change of the strength, resulting in excellent match between strength and plasticity.