通过对不同成分梯度激光沉积TC4/TC11钛合金试样沉积态和热处理态的显微组织、静载力学性能、拉伸断口、室温耐磨性能及显微硬度进行对比研究，探索改善激光沉积TC4/TC11钛合金组织，进而提高综合力学性能的途径。结果表明，当固溶时效热处理温度升高至970 ℃时，TC4/TC11钛合金显微组织中α板条的长宽比更小，其中球状α相和短棒状α相数目明显增多，且具有3层过渡区的显微组织更为均匀有序，过渡界面基本消失；不同成分梯度的固溶时效态试样的强度和塑性随着过渡层数的增加而增加；过渡层为1层和3层试样的摩擦系数曲线相似，过渡层为0层试样的摩擦系数较小，且不同成分梯度的固溶时效态试样磨损机理均主要为剥层磨损和黏着磨损；不同成分梯度试样的硬度排序为：沉积态<去应力退火态<固溶时效态。

In recent years, gradient composites have been increasingly used in life and industry. The rapid development of laser deposition manufacturing (LDM) technology realizes the manufacturing of dissimilar-metal gradient composite structure used for main bearing component. In this work, laser deposited TC4/TC11 gradient composite structures are taken as the research objects. Since there are few studies on TC4/TC11 titanium alloy, this work focuses on the effect of heat treatment on the microstructures and properties of TC4/TC11 titanium alloy, providing the basis to improve the quality and serving life of laser deposited gradient composite structure. Based on comparative study on the microstructures, residual static performances, tensile fractures, room temperature abrasion results and microhardnesses of laser deposition TC4/TC11 titanium alloy specimens with different composition gradients under different heat treatments, the ways to improve the laser deposition TC4/TC11 titanium alloy microstructure and the comprehensive mechanical properties were explored. Results show that when the temperature of solution and ageing treatment rises to 970 ℃, the length-width ratio of α laths of TC4/TC11 titanium alloy is less than that of the other heat treatment samples. The globular α phase and the short bar α phase are significantly increased. The microstructure of the three-layer transition zone is more uniform and orderly, and the transition interface almost disappears. With the increase of the number of transition layers, the strength and plasticity of solution and ageing samples with different component gradients are increased. The frictional coefficient curve of sample with 1 transition layer is similar to that of the sample with 3 transition layers. The friction coefficient of the sample with the transition layer of 0 is relatively small. The wear mechanism of solution and ageing samples with different component gradients are mainly lamination wear and adhesive wear. From the as-deposited state to the stress relieved and finally to the ageing state of solid solution, the corresponding hardness of the sample with different component gradients increases successively.