Temperature-dependent compression properties and failure mechanisms of ZrNiSn-based half-Heusler thermoelectric compounds  

作　　者：Yanyan Lu Pengxin Zhang Jinsong Wang Qingfeng Song Zhanhui Chen Yali Wang Lidong Chen Shengqiang Bai Wenzhi Wang 

机构地区：[1]School of Aeronautics,Northwestern Polytechnical University,Xi’an,Shaanxi 710072,China [2]State Key Laboratory of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China [3]School of Aviation,Beijing Institute of Technology,Zhuhai,Guangdong 519088,China [4]Analytical and Testing Center,Northwestern Polytechnical University,Xi’an,Shaanxi 710072,China

出　　处：《Journal of Materials Science & Technology》2024年第26期29-36,共8页材料科学技术(英文版)

基　　金：supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.U2141208 and 12141203);Shengqiang Bai acknowledges the support from the International Partnership Program of the Chinese Academy of Sciences(Grant No.121631KYSB20200012).

摘　　要：Half-Heusler(HH)compounds have emerged as promising candidates for high-temperature thermoelectric power generation;however,their mechanical properties in service environments have been scarcely reported.In this study,the temperature dependences of the mechanical responses and failure mechanisms of an n-type ZrNiSn-based HH compound(Zr_(0.5)Hf_(0.5)NiSn_(0.985)Sb_(0.015))were systematically evaluated through high-temperature compression tests and microfractographic characterization.The test results indicated that the elastic modulus and ultimate compressive strength of Zr_(0.5)Hf_(0.5)NiSn_(0.985)Sb_(0.015)decreased with increasing temperature.The stress-strain behavior of the material changed from linear(300,500,and 700 K)to nonlinear(900 and 1100 K).Microfractography observations revealed that increasing the temperature reduced the strength of the grain boundary as well as aggravated oxidation and segregation on the fracture surface,which significantly impacted the macro-compressive behavior of Zr_(0.5)Hf_(0.5)NiSn_(0.985)Sb_(0.015)at elevated temperatures.Finally,a stress-strain relationship for the ZrNiSnbased HH was proposed to describe the change in the compressive response from linear to nonlinear with increasing temperature.The present study elucidates the load-carrying and failure mechanisms of Zr_(0.5)Hf_(0.5)NiSn_(0.985)Sb_(0.015)within its operational temperature range,providing valuable guidance for the mechanical design of HH thermoelectric devices over their entire service temperature range.

关 键 词：Half-Heusler compounds Temperature dependence Mechanical response Failure mechanism 

分 类 号：TG1[金属学及工艺—金属学]