【摘要】 研究激光熔化沉积制备γ-TiAl合金沉积态和不同温度退火态样品的显微组织演变和力学性能。结果表明,沉积态试样的显微组织由细小α₂（Ti₃Al）+γ片层构成。随着退火温度的升高,块状γ_m（TiAl）相逐渐由单-γ相→γ相+针状α₂相→γ相+片层状α₂+γ方向转变。与沉积态γ-TiAl合金的力学性能（抗拉强度469 MPa、伸长率1.1%）相比,经1260℃、30 min、FC退火处理后,试样的室温抗拉强度为543.4 MPa,伸长率为3.7%,其力学性能得到显著提高。更多还原

【Abstract】 The microstructure evolution and mechanical properties of the as-deposited y-TiAl-based alloy specimen fabricated via laser melting deposition and as-annealed specimens at different temperatures were investigated.The results show that the microstructure of as-deposited specimen is composed of fine α₂（Ti₃ Al）+γ lamellae.With the increase of annealing temperature,the bulk γ_m（TiAl） phase gradually changes from single y phase to γ phase+acicularα₂ phase,finally small y phase+lamellar α₂+γ phase.Compared with the mechanical properties of as-deposited y-TiAl alloy（tensile strength 469 MPa,elongation 1.1%）,after annealing at 1260℃for 30 min followed by furnace cooling（FC）,the room-temperature tensile strength of the specimen is 543.4 MPa and the elongation is 3.7%,which are obviously improved.更多还原