Annealing hardening and deformation behavior of layered gradient Zr–Ti composite  

Zr-Ti层状梯度复合材料的退火硬化和变形行为

作　　者：Yang ZHOU Wei-jun HE Jia-teng MA Ze-jun CHEN Qing LIU 周杨;何维均;马佳腾;陈泽军;刘庆(重庆大学材料科学与工程学院,重庆400044;重庆大学教育部轻合金材料国际合作联合实验室,重庆400044)

机构地区：[1]College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China [2]International Joint Laboratory for Light Alloys(Ministry of Education),Chongqing University,Chongqing 400044,China

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第8期2358-2371,共14页中国有色金属学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51971041);the Natural Science Foundation of Chongqing,China(No.cstc2019jcyj-msxm X0234)。

摘　　要：To investigate potential strengthening approaches,multi-layered zirconium–titanium(Zr-Ti)composites were fabricated by hot-rolling bonding and annealing.The microstructures of these composites were characterized using scanning electron microscopy with energy dispersive spectroscopy(SEM-EDS)and electron backscatter diffractometry(EBSD).Their mechanical properties were evaluated by uniaxial tension and compression measurements.It was found that the fabricated Zr–Ti composites are composed of alternating Zr/diffusion/Ti layers,and chemical compositions of Zr and Ti showed a gradient distribution in the diffusion layer.Compared with as-rolled samples,annealing can strengthen the layered gradient Zr–Ti composite,and this is mainly caused by solid-solution strengthening and microstructure refinement-induced strengthening.Compared with the raw materials,a synergistic improvement of strength and ductility is achieved in the Zr–Ti composite as a result of the layered gradient microstructure.Tension–compression asymmetry is observed in the Zr–Ti composites,which may be attributed to twinning and microvoids induced by unbalanced diffusion.为了探寻潜在的强化途径,采用热轧及退火复合法制备Zr-Ti层状梯度复合材料。利用SEM-EDS和EBSD对复合材料的显微组织进行表征,并通过单轴拉伸和压缩试验对其力学性能进行测试。研究结果表明,Zr-Ti复合材料由交替的Zr层/扩散层/Ti层组成,扩散层中Zr、Ti元素成分呈梯度分布。与轧制态复合板相比,退火可显著提高Zr-Ti复合材料的强度,其主要机制是扩散层的固溶强化和组织细化诱导强化;与原始材料相比,Zr-Ti复合材料的强度和延性得到协同提高,这可能与特殊层状梯度结构有关。对比拉伸与压缩性能发现,Zr-Ti复合材料中存在拉、压不对称现象,这可能与孪生变形和非对等扩散引起的微孔有关。

关 键 词：Zr–Ti layered structural material diffusion annealing strengthening tension–compression asymmetry yielding ductility 

分 类 号：TB331[一般工业技术—材料科学与工程]