Zirconium carbide(ZrC)nanoparticles with an average size of 5.6 nm were synthesized through laser fragmentation(LF)from as-received 20-60 nm ZrC particles,and LF-ZrC nanoparticle dispersion-strengthened tungsten(LF-WZ...Zirconium carbide(ZrC)nanoparticles with an average size of 5.6 nm were synthesized through laser fragmentation(LF)from as-received 20-60 nm ZrC particles,and LF-ZrC nanoparticle dispersion-strengthened tungsten(LF-WZC)samples were fabricated by spark plasma sintering method.The average grain size of LF-WZC is 1.91μm and most ZrC particles in LF-WZC are smaller than 10 nm.LF-WZC exhibits finer grain size,higher yield strength and hardness but lower ductility as compared with W-ZrC samples using as-received ZrC(WZC).The results showed that finer ZrC nanoparticles dispersed in tungsten can enhance the strength by hindering the motion of dislocations,but they may also introduce stress concentra-tion and thus reduce the ductility.The thermal shock resistance of the WZC and LF-WZC samples was investigated using an electron beam device.The LF-WZC sample also exhibits a higher cracking threshold(0.33-0.44 GW·m^(−2))than WZC(0.22-0.33 GW·m^(−2))at room temperature.The enhanced thermal shock resistance of LF-WZC could be attributed to its high yield strength.展开更多
基金This work was financially supported by the National Key R&D Program of China(Grant Nos.2017YFE0302400,2017YFA0402800,and 2017YFE0300403)the National Natural Science Foundation of China(Grant Nos.51671184,11735015,51801203,and 11575231).
文摘Zirconium carbide(ZrC)nanoparticles with an average size of 5.6 nm were synthesized through laser fragmentation(LF)from as-received 20-60 nm ZrC particles,and LF-ZrC nanoparticle dispersion-strengthened tungsten(LF-WZC)samples were fabricated by spark plasma sintering method.The average grain size of LF-WZC is 1.91μm and most ZrC particles in LF-WZC are smaller than 10 nm.LF-WZC exhibits finer grain size,higher yield strength and hardness but lower ductility as compared with W-ZrC samples using as-received ZrC(WZC).The results showed that finer ZrC nanoparticles dispersed in tungsten can enhance the strength by hindering the motion of dislocations,but they may also introduce stress concentra-tion and thus reduce the ductility.The thermal shock resistance of the WZC and LF-WZC samples was investigated using an electron beam device.The LF-WZC sample also exhibits a higher cracking threshold(0.33-0.44 GW·m^(−2))than WZC(0.22-0.33 GW·m^(−2))at room temperature.The enhanced thermal shock resistance of LF-WZC could be attributed to its high yield strength.
