【摘要】 由于NiTi形状记忆合金(SMAs)具有高反应敏感性和低热导率等物性,导致其初步成形件的后续加工十分困难,作为一种典型的金属增材制造技术,选区激光熔化(SLM)在近净成形复杂几何形状的金属构件方面具有显著优越性,能够有效解决NiTi SMAs冷加工难、加工成本高的问题。为实现SLM NiTi SMAs的工程应用,需厘清其工艺参数-微观结构-功能特性的内在联系,揭示其相转变行为与功能特性变化的机理,建立坚实的理论基础。基于此,本文重点对SLM NiTi SMAs的成形性、相转变行为、微观结构、力学性能和热机械性能的相关研究结果进行了分析与总结。同时,对近来SLM多孔NiTi SMAs的设计及其生物相容性的探索研究进行了阐述。最后,本文展望了SLM NiTi SMAs研究过程中需要重点突破的问题。更多还原

【Abstract】 The postprocessing/machining of NiTi shape memory alloys(SMAs) is extremely challenging and difficult due to their low thermal conductivity and the high reactivity of ready-made NiTi parts. As a typical metal additive manufacturing technology, selective laser melting(SLM) offers significant advantages and can directly fabricate complex metallic parts, effectively address the problems of cold workability and machinability for NiTi parts. By establishing the relationship between processing parameters, microstructure, functional properties, and revealing the underlying mechanisms for altered phase transformation behavior and functional properties of SLM NiTi SMAs, it can serve as a theoretical foundation for expanding the applications of SLM NiTi SMAs. As a result, this paper comprehensively evaluates the formability, phase transformation behavior, microstructure, mechanical properties, and thermomechanical properties of SLM NiTi SMAs. Additionally, the design of SLM porous NiTi SMAs, as well as their biocompatibility, are discussed. Eventually, the future development trend and critical problems in studying SLM NiTi SMAs are investigated.更多还原