The effects of temperature and load on fretting fatigue induced geometrically necessary dislocation (GND) distribution in titanium alloy are studied by electron back-scattered diffraction (EBSD) in this paper. Fretting fatigue experiments under different temperature and load in TC11 titanium alloy are carried out and samples with small cracks are obtained. With Hough-based EBSD, the misorientation and GND densities induced by fretting fatigue are analyzed in both crack formation zone and crack tip. The results show that in the crack formation zone and crack tip, both temperature and load have obvious effects on the GND densities. With the increase of temperature and load, the GND densities rise significantly, which agrees with the decreasing tendency of fretting fatigue lives. The peak positions of GND density agree well with the crack formation locations, indicating the close relation between GND concentration and fretting fatigue crack formation. The relationship between GND density and distance from the crack path is studied. The results of individual GND densities on each slip system show that ‘Pyramidal<c+a>' and ‘Screw<a>' dislocations compose a majority of total GND density.

本文通过电子背散射衍射（EBSD）研究了温度和载荷对微动疲劳引起的钛合金中几何必要位错（GND）分布的影响。在TC11钛合金上进行了不同温度和载荷下的微动疲劳实验，得到了裂纹较小的试样。使用基于Hough的EBSD，分析了裂纹形成区和裂纹尖端中由微动疲劳引起的取向和GND密度。结果表明，在裂纹形成区和裂纹尖端，温度和载荷对GND密度都有明显影响。随着温度和负载的增加，GND密度显着增加，这与微动疲劳寿命的降低趋势相吻合。GND密度的峰值位置与裂纹形成位置非常吻合，表明GND浓度与微动疲劳裂纹形成之间存在密切关系。研究了GND密度与距裂纹路径的距离之间的关系。每个滑动系统上各个GND密度的结果表明，“金字塔形<c + a>”和“ Screw <a>”位错构成了总GND密度的大部分。