Ti_3Al/TC11合金焊接界面的高温性能

Elevated Temperature Properties of the Welding Interface for Ti_3Al/TC11 Alloy

研究了经真空电子束焊连接而成的Ti3Al/TC11合金在经过近等温锻造及不同制度的热处理后,连接界面的高温拉伸性能。结果表明,Ti3Al/TC11合金在500～600℃的高温拉伸性能差异较小,说明Ti3Al/TC11合金在此温度范围的高温拉伸性能比较稳定,可安全服役,尤其是以变形40%近等温锻造+梯度热处理的合金高温拉伸性能较佳,这和变形程度与组织中晶粒的形态、大小及分布有关。虽然焊接过程中在焊缝区形成了一些金属间化合物,但由于随后经过了近等温锻造和热处理,可在一定程度上使其破碎、重新分布而得到均匀细小的组织,因此改善了焊接界面的组织,提高了焊接界面的高温拉伸性能。

A number of Ti3Al/TC11 alloy specimens joined by electron seam welding in vacuum were deformed by near isothermal forging and different heat treatment regimes,respectively.Then the elevated temperature tensile properties of them were investigated.The results show that the differences in the elevated temperature tensile properties of Ti3Al/TC11 alloy specimens in the range of 500～600 ℃ are not obvious.This indicates that the elevated temperature tensile properties of them in this temperature interval are stable and the Ti3Al/TC11 alloy can operate in safety.Particularly,the elevated temperature tensile properties of the alloys are relatively better,which undergo near isothermal forging with 40% deformation amount and gradient heat treatment,and it is attributed to the relations among the deformation amount and the shape,size and distribution of the microstructure.Although some new intermetallics are formed in the welding zone,they are broken and redistributed in a certain degree due to the following near isothermal forging and heat treatment.Finally,the homogeneous and fine microstructure is obtained,so the microstructure of the welding interface for Ti3Al/TC11 alloy is improved and the elevated temperature tensile properties of them are also increased.