摘要
研究了电子束选区熔化增材制造Ti-48Al-2Cr-2Nb合金的显微组织与拉伸性能。Al含量的烧损导致显微组织呈现不均匀性,沉积态材料由较大的γ晶粒和被α_2晶粒钉扎的链状细小γ晶粒组成。γ相占据89%的体积,但并未显示出明显织构;而α_2相显示出14.1倍随机值的(0001)织构,其c轴与沉积方向平行。沉积态材料的室温抗拉强度达到503MPa,而塑性为0。热等静压与热处理后的材料强度稍有下降,但延伸率获得较大改善。直到800℃,双态组织TiAl-4822材料的抗拉强度仍在460MPa以上,而全片层组织材料则维持在400MPa以上。
The microstructure evolution and tensile properties of electron beam selective melted Ti-48A1-2Cr-2Nb alloy were studied. The Al loss caused an inhomogeneous microstructure. The as-build material is composed of large γ grains and small γ grains pinned by a chain-like α2 grains. The γ phase occupies 89% of the material volume and exhibits a weak texture, but the α2 phase exhibits a 14.1 times random （0001） texture with its c axis parallel to the build direction. The room temperature tensile strength of the as-build material is 503MPa but the ductility is 0. HIP and heat treatment lowered the tensile strength but improved ductility by a large extent. Up until 800℃, the TiAl-4822 with a duplex microstructure exhibits tensile strength higher than 460MPa; while the TiAl-4822 with a fully lamella microstructure exhibits tensile strength higher than 400MPa.
出处
《航空制造技术》
2017年第1期37-41,共5页
Aeronautical Manufacturing Technology
