Al

x

CrCuNiTi（x=0.2

0.4

0.6

1.0） high entropy alloys were prepared by arc melting process. The microstructure and hardness of the alloys prepared were characterized by X-ray diffraction（XRD）

scanning electron microscopy（SEM） and digital display Vickers hardness tester. The results reveal that the alloys are composed of a mixed structure of BCC1

BCC2 and FCC phases. With the increase of Al content

the FCC phase is decreased and the BCC phase is increased

which indicate that the Al element is in favor of the formation of BCC phase. The microstructure of the alloys presents a structure of dendrite and interdendrite. With the increase of Al element

the dendrite region is reduced while the interdendrite region is expanded in the Al

x

CrCuNiTi high entropy alloys. In addition

Al

Cr and Ti are segregated in the dendrite region

while Cu and Ni are segregated in the interdendrite region. The hardness of the Al

x

CrCuNiTi alloys is increased to 513 HV from 376 HV as the increase of Al content.