Resolving the sintering conundrum of high-rhenium tungsten alloys  

作　　者：Zhongyou Que Xingyu Li Lin Zhang Xuanhui Qu Zichen Wei Chenguang Guo Haishen Sun Mingli Qin Gang Chen Peinan Du Yanhao Dong 

机构地区：[1]Beijing Advanced Innovation Center for Materials Genome Engineering,Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China [2]Institute of Materials Intelligent Technology,Liaoning Academy of Materials,Shenyang 110004,China [3]Science and Technology on Reactor Fuel and Materials Laboratory,Nuclear Power Institute of China,Chengdu 610213,China [4]State Key Laboratory of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Journal of Materials Science & Technology》2023年第35期78-85,共8页材料科学技术（英文版）

基　　金：This work is financially supported by National Key R&D Pro-gram of China(no.2022YFB3700075);Natural Science Foundation of China(nos.52074032,51974029,52071013,52130407);Beijing Natural Science Foundation(no.2232084);Guangdong Basic and Applied Basic Research Foundation(no.2021B1515120033);Basic and Applied Basic Research Fund of Guangdong Province(no.BK20BE015);111 Project(no.B170003).

摘　　要：Tungsten-rhenium(W-Re)alloys with high-Re contents are the preferred refractory metal materials in many applications because of the improved ductility and processability over pure W and low-Re tung-sten alloys.However,the sintering concurrently becomes increasingly more difficult with increasing Re contents.Here we proposed that the sintering conundrum is caused by the lowered crystal symmetry and the wider dihedral angle distribution when body-center-cubic(BCC)W is alloyed with more hexagonal-close-packed(HCP)Re,which results in inefficient pore removal in the final stage sintering.We showed that the conundrum can be resolved by pressureless two-step sintering(TSS)which suppresses acceler-ating final-stage grain growth,and our proposal is supported by the data of the critical densityρc that is required to start the second step for successful TSS at different W-Re compositions.Dense ultrafine-grained W-Re alloys with∼300 nm average grain size and up to 25 wt%Re were successfully produced.Our work demonstrates the unique opportunities offered by two-step sintering to advance the scientific understanding and technological practices in powder metallurgy and related fields.

关 键 词：W-Re alloys Two-step sintering Grain growth Ultrafine-grained materials 

分 类 号：TF124.5[冶金工程—粉末冶金]