(浙江工业大学 材料科学与工程学院，杭州 310014)
摘 要: 表面自纳米化因可赋予钛及钛合金优异的综合性能而广受关注，该工艺可显著提高材料表面的强度、硬度与耐磨性，同时还可优化材料的耐蚀性、疲劳性能。介绍了几种表面自纳米化工艺，如表面机械研磨、喷丸强化、激光冲击、超声冲击等，阐明在这些工艺下钛与钛合金表面自纳米化的显微组织演变及其变形机理，如位错、层错、孪晶、第二相等，其滑移与攀移、孪生、形核与长大等行为及其相互作用规律。同时，梳理了表面纳米化组织对材料硬度、强塑性、耐磨性、疲劳性以及耐蚀性等影响规律，阐述各表面自纳米化工艺适用的钛合金类型及其应用背景。本文综述了钛与钛合金表面自纳米化工艺以及显微组织的演变规律，并对纳米化后钛与钛合金的特征力学性能以及关键变形机制开展了深入的探讨。
关键字: 钛；表面纳米化；显微组织；变形机制；力学性能
（College of Material Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China）
Abstract:Self-surface nanocrystallization of titanium and its alloys has attracted more and more attentions because of the enhanced comprehensive properties. Self-surface nanocrystallization can not only significantly optimize the strength, hardness and wear resistance of material surface, but also have a profound impact on corrosion resistance and fatigue property. This paper introduced various self-surface nanocrystallization methods, such as surface mechanical attrition treatment, shot peening, laser shock peening, ultrasonic impact treatment, etc. The microstructure of self-surface nanocrystallization of titanium and its alloys, such as dislocation, stacking fault, twin and secondary phase were expound. Besides, deformation mechanisms, such as dislocation slip and climb, twinning, nucleation and growth and their interaction were systemically studied. At the same time, the relationship among the microstructure of self-surface nanocrystallization and hardness, strength and plasticity, wear resistance, fatigue and corrosion resistance of materials were clarified, illustrating the different application background. In this paper, the self-surface nanocrystallization methods and microstructural evolution of titanium and its alloys were reviewed, and the mechanical properties and key deformation mechanism of nanocrystallized titanium and its alloys were deeply discussed.
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