基于固溶强化的激光定向能量沉积TiZr基高熵合金成分设计与强塑性优化  

Composition and Strength-plasticity Optimization of TiZr-based High-entropy Alloy through Solid Solution Strengthening by Laser Directed Energy Deposition

作　　者：邬良怡 于君[1,2] 林鑫[1,2] 闫乔单 王林增 牛毅豪 WU Liangyi;YU Jun;LIN Xin;YAN Qiaodan;WANG Linzeng;NIU Yihao(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design,MIIT China,Northwestern Polytechnical University,Xi'an 710072,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]西北工业大学高性能金属增材制造工信部重点实验室,陕西西安710072

出　　处：《铸造技术》2024年第8期783-792,共10页Foundry Technology

基　　金：国家自然科学基金(52105401);西安市重点产业链核心技术攻关项目(23ZDCYJSGG0033-2022)。

摘　　要：目前,部分TiZr基高熵合金由于大量脆性相的析出,呈现出强塑性难以平衡的问题,阻碍了合金作为复杂构件材料的工程应用。利用激光定向能量沉积技术基于混合元素法及非平衡快速凝固特性,实现成分设计的独特优势。通过调整TiZr基高熵合金主元成分,实现了非等原子比Ti39Zr39Nb11Mo5.5V5.5的致密成形,并获得了无金属间化合物等脆性相析出的单相固溶体合金。合金呈现出优异的塑性变形能力,其压缩应变超过了50%,而50%应变率时的压缩应力达2194 MPa。进一步分析表明,固溶强化是合金呈现较高强度的关键,其对屈服强度的贡献超过了75%。Currently,some TiZr-based high-entropy alloys have difficulty balancing strength and plasticity because of the large amount of brittle precipitation.This limitation hinders their engineering application as structural materials for complex components.Laser-directed energy deposition(LDED)technology provides unique advantages in composition design through the mixed element method and rapid nonequilibrium solidification.Therefore,the primary elements of the TiZr-based high-entropy alloys in this study were adjusted,leading to the achievement of a nonequiatomic Ti39Zr39Nb11Mo5.5V5.5 alloy with high relative density via LDED.Furthermore,a single-phase solid solution was obtained without the precipitation of brittle phases.The alloy exhibits excellent plastic deformation capability,with a compressive strain exceeding 50%.At a strain rate of 50%,the compressive stress reaches 2194 MPa.Solid solution strengthening contributes approximately 75%of the yield strength,which is crucial to the high strength of the alloy.

关 键 词：激光定向能量沉积 单相TiZr基高熵合金 强塑性平衡 固溶强化 

分 类 号：TB4[一般工业技术] TG146[一般工业技术—材料科学与工程]