热处理对TiAl基合金的组织结构和室温力学性能的影响

来源期刊：中南大学学报(自然科学版)1993年第3期

论文作者：陈进 黄伯云 曲选辉

文章页码：378 - 383

关键词：钛合金; 铝化钛; 金属间化合物; 热处理; 组织结构; 力学性能

Key words：titanium alloy; titanium aluminide; microstructure; property; intermetallic compound; heat-treatment

摘    要：本研究采用非自耗电弧熔炼制备了以2.0wt%Mn为添加元素,Al/Ti比分别为32/68、33/67、34/66和35/65的四个系列TiAl基合金.探讨了不同条件的热处理和热等静压(HIP)对显微组织结构和室温延性、强度的影响,得出以下结论:(1)随Al/Ti从32/68增加至35/65,合金最终组织中块状单相晶粒含量增多,片层组织减少,Ti₃Al(α₂)相对含量减少.合金的延性、强度值在Al/Ti比为34/66时达到最高值.(2)在高温下,压力对相平衡有显著的影响.当压力为1500atm时,对于合金Ti-34Al-2Mn(wt%),其α/(α+γ)转变温度可降至1150～1200℃之间.(3)具有(γ+α₂)片层结构晶粒和γ单相晶粒组成的双态组织的合金有较高的延性.

Abstract: Four series of TiAl alloys containing 2.0 wt%Mn,with the Al/Ti ratio being 32/68、33/67、34/66 and 35/65,were prepared with non-consumable electrode arc-melting.The effects of heat-treatments and Hipping on their structures and properties were investigated.The following conclusions were obtained:1.When the ratio of Al/Ti increased from 32/68 to 35/65,the amount of γ-single phase grains increased,(γ+α₂)laminae and the content of Ti₃Al decreased.Both the ductility and strength reached their maximums at 34/66.2.The effect of pressure on phase equilibria was very singnificant at high temperatures.When pressure was 1500 atm,the α/(α+γ)transformation temperature of Ti-34Al-2Mn alloy was possibly changed to the region between 1150～1200(?).3.The alloys with the microstructure of a mixture of single γ-phase grains and some(γ+α₂)laminal grains showed better ductility.