| As a kind of new alloy material,high entropy alloys break through the traditional alloy design concept on the base of “one or two major alloy elements”. HEAs are composed of five or more elements which have equal mole or near equal mole ratios. High entropy effects in high entropy alloys arising from the mixture of multi-principal elements, promote the formation of random solid solution with simple BCC or FCC structures usually accompanied with a little intermetallics within the grains, which can strengthen the properties. We can optimize the design of alloy composition to obtain high entropy alloys with high strength, high hardness, high temperature creep resistance, high temperature oxidation resistance, abrasion resistance and corrosion resistance. As a result, high entropy alloys have great potential applications.In this paper, TaMoWNbZr、ZrTiHfNbMo、ZrTiHfVTa and ZrTiHfVNb with equal mole ratios of five elements which selected from Ta、Mo、W、Nb、V、Zr、Hf and Ti were prepared by NCAM. The microstructres, phase structures were studied by XRD, OM, SEM, EDS. Furthermore, the microhardness, static compression properties, dynamic compression properties and high-temperature compression properties were studied.It was found that ZrTiHfNbMo, ZrTiHfVTa and ZrTiHfVNb alloys had single phase body-centered cubic(BCC) structure. The phases of TaMo WNbZr alloy was BCC and an unknown phase which contained Zr. These four alloys form dendritic morphology structures during solidification. The hardness of these four high entropy alloys is in the range from 356 to 527, and the static compressive strength is in the range from 1123 MPa to 1609 MPa. The dynamic compression curves suggest that Zr TiHfNbMo and ZrTi HfVTa alloys had strain rate strengthing effects. The hightemperature compression curves indicate that ZrTiHfNbMo alloy had high temperature softening resistance property. As a result of their bad high-temperature strength, Zr TiHfVTa and ZrTiHfVNb alloys are not fit for high temperature application. |
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