具有储存与释放弹性能量能力的弹性材料在宏观和微观机械系统中均发挥着至关重要的作用。然而，由于金属材料普遍存在显微缺陷，其可实现的线弹性应变通常受到限制(＜ 2%)，或伴随较大的滞后效应，提高金属的弹性应变是一个重大挑战。本研究提出了一种增强形状记忆合金(SMAs)线弹性变形的新策略，并通过实验在Cu基SMAs中进行了验证。该策略依赖于粉末冶金制备过程中，由元素粉末原料引入的第二软相(包括Kirkendall孔隙与间隙孔)与具有择优软取向的基体相之间的相互作用。通过低温反应烧结与放电等离子体烧结(SPS)工艺的结合，在Cu71Al18Mn11 SMAs基体中引入了孔隙率为11.4%～31.1%、孔径为0.5～10 μm的第二相孔隙软相。异常晶粒长大过程促使基体形成了择优取向<101>的织构与小角度晶界结构，并减少了晶界处的γ2相含量。最终，所设计的多孔Cu71Al18Mn11 SMAs表现出优异的弹性能量储存性能(弹性能量密度Ue > 21.1 MJ/m3，能量效率η > 0.86)、较大的近线性可恢复应变(近弹性变形，约8%)、较低的能量耗散以及极低的温度依赖性。本研究提出的策略可拓展至其他高性能SMAs体系，如Ni-Ti基和Fe基SMAs，以实现块体金属或结构材料的高弹性变形性能。

Elastic materials that store and release elastic energy play pivotal roles in both macro and micro mechanical systems. However, it remains a significant challenge as metals generally suffer from a limited linear elastic strain of < 2% or large hysteresis due to its microscopic defects. Here, we presented a new strategy for enhancing the linear-elastic deformation of shape memory alloys (SMAs) and this put forward strategy was demonstrated in a Cu-based SMAs through experiments. This strategy relies on the interaction between the second soft phase including Kirkendall and interstitial pores and the soft-oriented strong texture matrix phase caused by powder metallurgy preparation process as elemental powders used as raw materials. In this work, the second phase pore soft phase with porosity of 11.4~31.1% and pore size of 0.5~10 μm was introduced into Cu71Al18Mn11 SMAs matrix through the combining of low temperature reactive sintering and spark plasma sintering process. The abnormal grain growth process realized the preferred texture of <101>-oriented and small angle grain boundary of matrix phase, as well as the reduced γ2 phase at the grain boundary. As a result, the designed porous Cu71Al18Mn11 SMAs demonstrated excellent elastic energy storage performance (elastic energy density Ue > 21.1 MJ/m3, efficiency η > 0.86), large recoverable near linear strain (near-elastic strain,~8%), and low energy dissipation simultaneously as well as ultra-low temperature dependence rate. This strategy may be applicable to other SMAs such as Ni-Ti-based and Fe-based SMAs with high performance to achieve high elastic deformation of bulk metals or construction.