WMoTaNbTi RHEAs formed by SEBM with negative defocus distance were investigated.Four scanning speeds were applied,an electron beam with scanning speed at 2.5 m/s completely fused the premixed WMoTaNb alloyed powder and pure Ti powder.Significant vaporization of Nb and Ti elements happened during the formation of WMoTaNbTi RHEAs,however,the single BCC phase remains stable.Weakened solid-solute strengthening caused by elemental vaporization,dropping percentage of Nb and Ti solutes in the matrix as well as improved ductilizing effects with decreasing scanning speeds leads to falling microhardness and better local ductility.Microhardness of scanning speed at 4.0 m/s,3.5 m/s,3.0 m/s and 2.5 m/s is 578±17 HV,576±12 HV,573±10 HV and 511±2 HV,respectively.The as-deposited WMoTaNbTi RHEA formed at a scanning speed of 2.5 m/s displays ultimate strength of 1312 MPa.

Bang Xiao;Wenpeng Jia;Huiping Tang;Jian Wang;Lian Zhou

State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;State Key Laboratory of Porous Metal Materials,Northwest Institute for Non-ferrous Metal Research,Xi'an 710016,China

材料科学技术（英文版）

[1]Bang Xiao;Wenpeng Jia;Huiping Tang;Jian Wang;Lian Zhou-.Microstructure and mechanical properties of WMoTaNbTi refractory high-entropy alloys fabricated by selective electron beam melting)[J].材料科学技术（英文版）,2022(13):54-63

WMoTaNbTi,WMoTaNb,Weakened,ductilizing,RHEA

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