Ti-1Al-8V-5Fe合金的组织和力学性能研究

Study on Microstructure and Mechanical Properties of Ti-1Al-8V-5Fe Alloy

采用铸造、锻造工艺获得组织均匀的Ti-1Al-8V-5Fe(Ti185)合金棒材,分析了该合金的组织形貌和力学性能。结果表明,Ti185合金中没发现成分偏析导致的"β斑"或Fe元素的富集现象。棒材中初始β相晶粒尺寸达到800μm,在β相晶粒内部析出高密度的α相。在室温下,锻态Ti185合金的抗拉强度为1192 MPa,伸长率为1.7%。经过950℃的固溶热处理及450℃的时效处理后,热处理态的Ti185合金α相尺寸和数量明显减少,合金的室温抗拉强度仍达到1275 MPa,伸长率同样达到1.65%。在400℃的高温拉伸条件下,锻态Ti185合金抗拉强度较室温大幅降低,抗拉强度为877 MPa。而热处理态的Ti185合金抗拉强度并没有大幅改变,抗拉强度为1375 MPa。

The homogeneous Ti-1 Al-8 V-5 Fe(Ti185) alloy bar was obtained by casting and forging. The microstructure and mechanical properties of the alloy were analyzed. The results show that, the enrichment of "β spot" or Fe element caused by composition segregation is not found in Ti185 alloy. The initial β-phase grain size in the bar reaches 800 μm, and the high density α phase is precipitated in the β-phase grain. At room temperature, the tensile strength and elongation of forged Ti185 alloy are 1192 MPa and 1.7% respectively. After solid solution heat treatment at 950 ℃ and aging treatment at 450 ℃, the αphase size and quantity of heat treated Ti185 alloy are obviously reduced. The tensile strength of the alloy at room temperature is still 1275 MPa, and the elongation is 1.65%. Under the condition of high temperature tensile at 400 ℃, the tensile strength of forged Ti185 alloy is much lower than that at room temperature, and the tensile strength is 877 MPa. However, the tensile strength of Ti185 alloy in heat treated state has not changed greatly, and the tensile strength is 1375 MPa.