背应力平衡策略实现非均质Al-SiC复合材料的强塑性协同  

Back stress dynamic balancing strategy enabled strength-ductility synergy in heterostructured Al-SiC composites

作　　者：冒冬鑫 孟祥晨 谢聿铭 常月鑫 秦志伟 许双明 万龙 黄永宪 Dongxin Mao;Xiangchen Meng;Yuming Xie;Yuexin Chang;Zhiwei Qin;Shuangming Xu;Long Wan;Yongxian Huang(State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,China;Zhengzhou Research Institute,Harbin Institute of Technology,Zhengzhou 450000,China;China Aerospace Science and Technology Corporation,Beijing 100000,China)

机构地区：[1]State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,China [2]Zhengzhou Research Institute,Harbin Institute of Technology,Zhengzhou 450000,China [3]China Aerospace Science and Technology Corporation,Beijing 100000,China

出　　处：《Science China Materials》2023年第4期1649-1658,共10页中国科学（材料科学（英文版）

基　　金：jointly supported by China National Postdoctoral Program for Innovative Talents(BX20220384);the National Natural Science Foundation of China(52175301);the Natural Science Foundation of Heilongjiang Province(JJ2020JQ085);China Postdoctoral Science Foundation(2021T140151)。

摘　　要：高强复合材料的低位错存储性能及其引发的强塑倒置问题阻碍了该系列材料的进一步发展.本文通过新颖的形变驱动冶金方法,设计了一种巧妙的具有粗细晶粒异质结构的纳微混合SiC增强铝基复合材料.基于背应力理论对累积的几何必须位错和晶内分散的SiC颗粒进行调控,使得背应力与外在施加应力保持动态平衡.这是本策略实现材料强塑性协同的关键.所设计的SiC_(5np-5μp)/Al复合材料的极限抗拉强度和均匀伸长率分别为324 MPa和12.9%,达到SiC_(10μp)/Al抗拉强度的181%,而塑性仅损失了约3%.因此,本文提供了一种基于背应力优化的强度-塑性协同新策略.Strength-ductility trade-off dilemma remains a significant obstacle to high-strength composites due to the undesirable dislocation storability.Herein,an ingenious nano-micro SiC-reinforced Al matrix composite(AMC)with heterogeneous grain structures of coarse and fine grains was designed via a novel deformation-driven metallurgy method.The accumulated geometrically necessary dislocations and the intragranularly dispersed SiC particles were tailored based on the principle of back stress amelioration,which was a key point to maintain the dynamic balance with the applied stress toward strength-ductility synergy.The ultimate tensile strength and uniform elongation of the designed SiC_(5np-5μp)/Al composite reached 324 MPa and 12.9%,respectively,and the strength was 181%as high as that of the SiC_(10μp)/Al with only 3%ductility loss.As such,a new strategy was provided herein to promote strength-ductility synergy via the further modified back stress.

关 键 词：几何必须位错 极限抗拉强度 SIC颗粒 平衡策略 应力优化 异质结构 强塑性 存储性能 

分 类 号：TB333[一般工业技术—材料科学与工程]