Abstract
From the perspective of high-temperature applications,materials with excellent high-temperature me-chanical properties are always desirable.The present work demonstrates that the binder-free nanopoly-crystalline WC ceramic with an average grain size of 103 nm obtained by high-pressure and high-temperature sintering exhibits excellent mechanical properties at both room temperature and high tem-perature up to 1000℃.Specifically,the binder-free nanopolycrystalline WC ceramic still maintains a considerably high Vicker hardness Hv of 23.4 GPa at 1000℃,which is only 22％lower than the room temperature Hv.This outstanding thermo-mechanical stability is superior to that of typical technical ce-ramics,e.g.SiC,Si3N4,Al2O3,etc.Nanocrystalline grains with many dislocations,numerous low-energy,highly stable Σ2 grain boundaries,and a relatively low thermal expansion coefficient,are responsible for the observed outstanding high-temperature mechanical properties.
基金项目
国家重点研发计划(2018YFA0305900)
Natural Science Basic Research Program of Shaanxi Province(2020JQ-870)
国家自然科学基金(52090020)
国家自然科学基金(U20A20238)
国家自然科学基金(51772260)
国家自然科学基金(91963203)
国家自然科学基金(51525205)
NSF for Distinguished Young Scholars of Hebei Province of China(E2018203349)
中国博士后科学基金(2017M620097)
NETL
NSTL
维普
万方数据