High-entropy alloys(HEAs)have attracted increasing attention because of their unique properties,including high strength,hardness,chemical stability,and good wear resistance.Powder metallurgy is one of the most importa...High-entropy alloys(HEAs)have attracted increasing attention because of their unique properties,including high strength,hardness,chemical stability,and good wear resistance.Powder metallurgy is one of the most important methods used to fabricate HEA materials.This paper introduces the methods used to synthesize HEA powders and consolidate HEA bulk.The phase transformation,microstructural evolution,and mechanical properties of HEAs obtained by powder metallurgy are summarized.We also address HEA-related materials such as ceramic–HEA cermets and HEA-based composites fabricated by powder metallurgy.展开更多
ZrB2 ceramics with various hexagonal BN(hBN)additions up to 37 vol%were reactively densified by spark plasma sintering using powder mixtures containing ZrB2,ZrN and boron.ZrN-boron based additives effectively promoted...ZrB2 ceramics with various hexagonal BN(hBN)additions up to 37 vol%were reactively densified by spark plasma sintering using powder mixtures containing ZrB2,ZrN and boron.ZrN-boron based additives effectively promoted the densification process,ZrB2 ceramics reached>99%relative density at 2000℃and an applied pressure of 60 MPa with only 5 vol%in-situ formed hBN,whereas the relative density of pure ZrB2 was only 91.2%at the same conditions.Increasing thehBN contents,the morphology of hBN grains gradually changed from quasi-spherical to flake dominated,which has substantial influence on their mechanical properties.In-situ ZrB2-10 vol%hBN ceramics demonstrated high flexural strength of 597±22 MPa,relatively low Young’s modulus of 406 GPa and good machinability,especially for the impressively large strain to failure(1.47×10^-3)which is superior to most of their counterparts in the ZrB2 based particulate reinforced ceramics.展开更多
基金The authors are grateful to the National Key Research and Development Plan of China(No.2017YF130310400)the National Natural Science Foundation of China(Nos.51521001 and 51902233)+1 种基金the Self-determined and Innovative Research Funds of WHUT(Nos.2018III020 and 2018IVA094)the Students Innovation and Entrepreneurship Training Program of WHUT(Nos.2018CLA127 and 20181049701037).
文摘High-entropy alloys(HEAs)have attracted increasing attention because of their unique properties,including high strength,hardness,chemical stability,and good wear resistance.Powder metallurgy is one of the most important methods used to fabricate HEA materials.This paper introduces the methods used to synthesize HEA powders and consolidate HEA bulk.The phase transformation,microstructural evolution,and mechanical properties of HEAs obtained by powder metallurgy are summarized.We also address HEA-related materials such as ceramic–HEA cermets and HEA-based composites fabricated by powder metallurgy.
基金supported financially by grants from the National Natural Science Foundation of China(NSFC)(No.51972243 and 51521001)。
文摘ZrB2 ceramics with various hexagonal BN(hBN)additions up to 37 vol%were reactively densified by spark plasma sintering using powder mixtures containing ZrB2,ZrN and boron.ZrN-boron based additives effectively promoted the densification process,ZrB2 ceramics reached>99%relative density at 2000℃and an applied pressure of 60 MPa with only 5 vol%in-situ formed hBN,whereas the relative density of pure ZrB2 was only 91.2%at the same conditions.Increasing thehBN contents,the morphology of hBN grains gradually changed from quasi-spherical to flake dominated,which has substantial influence on their mechanical properties.In-situ ZrB2-10 vol%hBN ceramics demonstrated high flexural strength of 597±22 MPa,relatively low Young’s modulus of 406 GPa and good machinability,especially for the impressively large strain to failure(1.47×10^-3)which is superior to most of their counterparts in the ZrB2 based particulate reinforced ceramics.
