Equiatomic CuZrAl and CuZrAlTi medium entropy alloys were designed and synthesized by mechanical alloying and spark plasma sintering technique.The alloying behavior,phase evolutions,microstructures and properties of samples were investigated by X-ray diffraction,differential scanning calorimetry,field emission scanning electron microscopy,microscopy/Vickers hardness testing and electrochemical polarization measurement.The results indicate that the final products of as-milled alloys consist of amorphous phases.Ti addition improves the glass forming ability of as-milled alloys.The as-sintered CuZrAl alloy contains face-centered cubic(fcc)solid solution,Al_(1.05)Cu_(0.95) Zr and AlZr_2 phases at different sintering temperatures.With Ti addition,the as-sintered sample is only composed of intermetallics at 690°C,while fcc1,fcc2 and CuTi3phases are formed at 1100°C.CuZrAlTi-1100°C alloy exhibits the highest hardness value of 1173HV0.2owing to the high sintering density,solid solution strengthening and homogeneous precipitation of nano-size crystalline phase.CuZrAlTi-690°C alloy presents a similar corrosion resistance with304 Lstainless steel in seawater solution and further possesses the lower corrosion rate. Equiatomic CuZrAl and CuZrAlTi medium entropy alloys were designed and synthesized by mechanical alloying and spark plasma sintering technique. The alloying behavior, phase evolutions, microstructures and properties of samples were investigated by X-ray diffraction, differential scanning calorimetry, field emission scanning electron microscopy, microscopy / Vickers hardness testing and electrochemical polarization measurement. The results indicate that the final products of as-milled alloys consist of amorphous phases. Ti addition improves the glass forming ability of as-milled alloys. The as-sintered CuZrAl alloy contains face-centered cubic (fcc) solid solution, Al_ (1.05) Cu_ (0.95) Zr and Al_Zr_2 phases at different sintering temperatures.With Ti addition, the as-sintered sample is composed only of intermetallics at 690 ° C, while fcc1, fcc2 and CuTi3phases are formed at 1100 ° C.CuZrAlTi-1100 ° C alloy exhibits the highest hardness value of 1173HV0.2owing to the high sintering density, solid solution stre ngthening and homogeneous precipitation of nano-size crystalline phase. CuZrAlTi-690 ° C alloy presents a similar corrosion resistance with 304 Lstainless steel in seawater solution and further possesses the lower corrosion rate.