面心立方中熵合金强韧化及力学性能研究进展

Research Progress on Strengthening and Toughening and Mechanical Properties of Face-centered Cubic Medium-entropy Alloys

中熵合金是由3种主要元素组成的新型金属材料,具有高强度、高硬度、良好的高温抗软化性能、较高的低温韧性和丰富的设计性等优异性能,在诸多领域均具有广泛的应用前景,受到国内外学者的高度重视。然而,为了满足高精尖领域对高性能材料日益增长的需求,面心立方中熵合金的强度仍有巨大的提升空间,需要通过合金设计和制备工艺来调控强韧化机制。中熵合金力学性能的提升已从单一的强韧化机制,转向综合运用多种强韧化机制的协同作用,中熵合金应用的温度范围也由室温拓展到高温和低温环境。为了研究设计兼具高强度与高塑韧性的中熵合金。首先归纳了面心立方中熵合金的强韧化机理(固溶强化、形变强化、细晶强化、第二相强化、异质形变诱导(HDI)强化)以及变形机制(位错、孪晶、短程有序)对力学性能的影响,同时概括了中熵合金独有的特性。其次总结了中熵合金与传统合金在极端环境(高温和低温)下的力学性能并进行对比。最后对未来面心立方中熵合金强韧化研究和发展方向进行了展望。

The medium-entropy alloy is a novel metal material comprising three primary elements.Due to its high strength,hardness,excellent high-temperature softening resistance,superior low-temperature toughness,and versatile design capabilities,it has a wide range of application prospects in many fields and has been highly valued by scholars in China and abroad.However,in order to meet the increasing demand for high-performance materials in high-tech fields,there is still a huge room for im-provement in the strength of face-centered cubic medium-entropy alloys,and the strengthening and toughening effects need to be regulated by alloy design and preparation process.In the research field of medium-entropy alloys,the improvement of me-chanical properties of medium-entropy alloys has shifted from a single strengthening and toughening mechanism to the syner-gistic effect of multiple strengthening and toughening mechanisms.The temperature range for the application of me-dium-entropy alloys has also expanded from room temperature to high and low temperature environments.The work aims to study and design a medium-entropy alloy with both high strength and high plasticity and toughness.Firstly,the effects of strengthening and toughening mechanisms(solid solution strengthening,deformation strengthening,grain refinement strength-ening,second phase strengthening,hetero-deformation induced strengthening)and deformation mechanisms(dislocations,twins,short-range order)on the mechanical properties of medium-entropy alloys in face-centered cubic were summarized.At the same time,the unique characteristics of medium-entropy alloys were summed up.Secondly,the mechanical properties of me-dium-entropy alloys and traditional alloys in extreme environments(high temperature and low temperature)were summarized and compared.Finally,the future research and development direction of strengthening and toughening of entropy alloys in face-centered cubic were prospected.