| High-entropy (HE) alloy has been widespread concerned at home and abroad since 1995 when it was proposed, and now it has developed into a new developing alloy system. It breaks through the traditional alloy design frame work which is based on one major alloy element. And we can optimize the design of alloy composition to obtain an exceptional combination of high hardness, high-strength, high temperature oxidation resistance, high temperature creep resistance and corrosion resistance. Therefore, the HE alloys have potential suitable for many applications.In this paper, the TiZrHfNbMo alloy system was studied. In order to improve its properties, we add C and B to the alloy, then we got (TiZrHfNbMo)100-xCx and (TiZrHfNbMo)100-xBx alloys(x=1.96,3.85,7.41,10.41 and 16.67) We also had high-temperature forging and heat treatment for the cast TiZrHfNbMo alloy .The microstructures and phase structures were investigated by OM, SEM, EDS, and XRD. Furthermore, the hardness and compression properties were also tested and analysised. Analysis showed that the phases of all the cast alloys in this study are simple BCC solution structure, and form dendritic structures. After adding C and B, the intermetallic compounds was observed in (TiZrHfNbMo)100-xCx and (TiZrHfNbMo)100-xBx alloys. Due to solid solution strengthening and precipitation strengthening, the hardness was increased with the increase of C and B content, (TiZrHfNbMo)83.33C16.67 and (TiZrHfNbMo)83.33B16.67 have the highest hardness, 739HV and 645HV respectively. In addition, the compressive strength, yield strength and plastic deformation were increased, (TiZrHfNbMo)92.59C7.41 has the best compression properties, the compressive strength, yield strength and plastic deformation are 2061MPa, 1421MPa, and 19.34% respectively. (TiZrHfNbMo)83.33B16.67 has the highest compressive strength (2310MPa), but it has no plastic deformation. All the alloys perform fracture during the compression process.We had the heat treatment at 1500℃, it found that the microstructure was changed and refined, the elements became more uniform, and there were two different types of morphologies appeared. The hardness of the alloy after heat treatment is up to 512HV, increased 19.6% compared with the cast hardness. We had the cast TiZrHfNbMo alloys forged at 1000℃, due to the different deformation the forged organization was divided into three regions. One is cast dendrite, the middle is flow organization, and on both sides is the thick dendrite. The phases of the forged and heat treated alloy are also simple BCC solution structure.
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