TC4-DT钛合金磨削表面特性及其摩擦磨损性能

钛合金是一种典型难磨削加工材料，磨削表面易出现烧伤、裂纹等热损伤。本文开展了TC4-DT钛合金磨削实验，通过扫描电镜（SEM）、能谱（EDS）、X射线衍射（XRD）、显微硬度仪、金相显微镜及球-盘摩擦磨损实验仪研究了其表面特性及摩擦磨损性能。结果表明：低速磨削表面质量好，摩擦磨损性能较基体略提高；当砂轮线速度为80 m/s时，磨削表面质量良好，摩擦系数为0.38，较基体降低40%；而砂轮线速度为100 m/s时，磨削表面出现严重烧伤、网状裂纹。因此选择合理的高速磨削工艺可避免烧伤、裂纹等热损伤缺陷，并可有效改善表面摩擦磨损性能；磨削表面干摩擦磨损机制为磨粒磨损、粘着磨损和剥层磨损。

Characteristics and Wear Properties of Grinding Surface of Titanium Alloy TC4-DT

Titanium alloy is a difficult-to-grind material. The grinding surface can be easily damaged during the grinding process because of the high grinding temperature. Grinding experiments were performed in this study to investigate the grinding surface properties of titanium alloy TC4-DT using the SEM, EDS, XRD, Microhardness tester, Metallographic microscope and ball-disk friction wear tester. The results show that good quality grinding surface with improved wear property of TC4-DT can be obtained when the grinding speed is relatively low. When the grinding speed is 80 m/s, good quality surface is obtained with the friction coefficient of 0.38, which is 40% lower than the matrix. However, burns and micro cracks appear when the grinding speed is 100 m/s. So burns and cracks can be avoided by choosing reasonable grinding parameters. The dry wear mechanisms of the grinding surface are adhesive abrasion, abrasive grain abrasion and delamination abrasion.