变形温度对摩擦焊件显微组织与拉伸性能的影响

异种合金焊接件在航空工业中显示出巨大的应用潜力。针对线性摩擦焊接的Ti2AlNb/TC11焊件接头抗拉强度低和塑性差的特点,对其进行热变形,研究变形温度对焊件接头显微组织与拉伸性能的影响。结果表明,在温度950℃变形后,焊件室温拉伸时在Ti2AlNb合金侧出现脆性断裂;在温度1010℃变形后,母材TC11合金显微组织严重粗化,焊件在室温下表现出一定的强度,但是塑性较差;当在温度980℃变形时,焊件不仅具有较高的强度,也表现出极好的韧性,这与所观察到的显微组织特点相一致。

Effect of hot deformation temperature on microstructure and tensile strength of friction weldment

The dissimilar joining of titanium alloys could have a major application in the aerospace industry.However,the as-welded linear friction joint of Ti2AlNb/TC11 exhibited low strength and poor ductility.Hot deformation plus heat treatment were applied to the linear friction welded Ti2AlNb/TC11 joint and the effect of hot deformation temperature on the microstructure and tensile strength of the weldment were investigated.The results show that the Ti2AlNb base metal would exhibit low strength and poor ductility when the weldment is hot deformed at 950℃,coarse widmanstatten would appear in the microstructure of the base metal TC11 alloy and result in poor plasticity after hot deformation at 1010℃,and the microstructure would exhibit the highest strength and best ductility after hot deformation at an appropriate temperature followed by aging and solution treatment.