Linear friction welding (LFW) offers a new approach to manufacture aerospace components while improving the buy-to-fly ratio. However, the fundamental knowledge associated with the LFW process, including the attendant microstructural evolution and corresponding mechanical behavior is still rather limited. In this research effort, subscale tensile coupons were prepared and tested to determine the properties of each discrete zone of the linear friction welded specimen, namely the welded zone, thermomechanically affected zone, and parent material. The results show that the yield strength of the welded zone is 20 pct higher than the parent material and the thermomechanically affected zone is 13 pct higher than the parent material. Materials characterization, including optical microscopy, scanning electron microscopy, electron backscattered diffraction-based orientation microscopy and transmission electron microscopy, was conducted to develop an understanding of the microstructure–property relationships. The highly refined nature of the microstructure makes final interpretations challenging, but the evidence suggests that the mechanical behavior is dominated by phenomenon that operate at the 1 to 50 nm length scale, including strain hardening and highly refined features that hinder slip.

线性摩擦焊接（LFW）提供了一种新的方法来制造航空航天零部件，同时提高了“飞购”比。但是，与LFW工艺相关的基础知识，包括伴随的微观结构演变和相应的机械行为，仍然相当有限。在这项研究工作中，准备并测试了小规模的拉伸试样，以确定线性摩擦焊接试样的每个离散区域的性能，即焊接区域，热机械影响区域和母体材料。结果表明，焊接区的屈服强度比母材高20 pct，热机械影响区比母材高13 pct。材料表征，包括光学显微镜，扫描电子显微镜，进行了基于电子反向散射衍射的定向显微镜和透射电子显微镜，以加深对微观结构-性能关系的理解。微观结构的高度精细特性使最终解释具有挑战性，但是证据表明，机械行为受在1至50 nm长度尺度上起作用的现象支配，包括应变硬化和阻碍滑动的高度精细特征。