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2026年9月4日，课题组青年教师苟峻铭博士的一篇论文“Double-peak age strengthening of magnetostriction in heterogeneous Fe-Ga alloy”被金属材料领域旗舰刊物ACTA MATERIALIA录用！这也是他今年以第一或通讯作者在该刊物连续发表的第2篇论文，向他表示热烈祝贺！论文合作者包括在读博士生陈莹、已毕业博士生张艺群、刘叠和刘孝莲（通讯作者）和马天宇教授（共同通讯作者）。

论文简介：

       过饱和固溶体合金在等温时效过程中，随着溶质富集区的形成及不同构型沉淀相的先后析出，会随时效时长先后出现两个力学性能（强度或硬度）峰值，即“时效双峰现象”。本工作在Fe-Ga合金过饱和固溶体中研究发现，其功能特性（磁致伸缩性能）也会随等温时效时长出现“双峰”。系统的微结构研究表明，磁致伸缩峰值源于贫Ga共格四方相和富Ga单斜相的先后析出。因此，等温时效不仅可以获得力学性能“双峰”增强效应，还可以产生功能特性“双峰”增强效应，为研发高性能功能合金赋予了更多自由度。

论文摘要：

Artificial aging is a powerful approach to strengthen most structural alloys owing to the precipitation of mechanically harder particles, and a large portion of structural alloys exhibit a “harder-to-softer-to-harder” transition when extending the aging time, an effect known as “double-peak age strengthening”. Beyond this, here we report a “double-peak age strengthening” effect of functional properties—magnetostriction (magnetic-field-induced elastic strain), well corresponding to two successive microhardness softening states, as exhibited in a proof-of-principle reference Fe₇₃Ga₂₇ alloy. During isothermal aging process, the body-centered-cubic (BCC) supersaturated solid solution undergoes concurrent ordering of matrix and successive precipitations of Ga-depleted tetragonal L6₀ and Ga-enriched ω/M (ω is a hexagonal phase; M is a monoclinic Fe₁₃Ga₉-type phase) nanoparticles with extending aging time. The first magnetostriction peak arises from the nucleation of coherent  L6₀ nanoprecipitates, following which the magnetostriction drops due to the formation of ω nanoprecipitates as well as the phase-transition-induced dislocations. The second peak appears when the coherent M nanoparticles precipitate and the phase-transition-induced dislocations are reduced, prior to the formation of incoherent L6₀/L1₂ phases. Upon reaching these two critical conditions, the saturation magnetostriction is nearly ~3 times higher than that of the solution-treated counterpart. Such double-peak age strengthening effect of magnetostriction was observed at a metastable phase-transition state, which may provide more freedoms for tuning the functional properties of heterogeneous alloys.