Investigation of phase-transformation path in TiZrHf(VNbTa)x refractory high-entropy alloys and its effect on mechanical property

•TiZrHfVxNbxTax BCC high-entropy alloys were designed by Bo-Md alloy design method.•TiZrHfV0.1Nb0.1Ta0.1 exhibits strain-hardening with deformation-induced phase transformation from BCC to HCP.•TiZrHfV0.1Nb0.1Ta0.1 reveals the stepwise transformation process, β to α″ at early strain and β to α′ or α″ to α′ at high strain.