Ti35Zr30Be27.5-xCu7.5Coxbulk amorphous alloys with xof 0

3.5

7.5

11.5were prepared by copper mold casting method.Effects of Co addition on mechanical properties of Ti-Zr based amorphous alloys were investigated using X-ray diffractometer（XRD）

universal testing machine and scanning electron microscope（SEM）.The results reveal that with appropriate substitution of Co for Be

the mechanical properties of Ti-Zr based amorphous alloys are significantly enhanced.With Co content of 3.5%

the Ti35Zr30Be24Cu7.5Co3.5bulk amorphous alloy has the highest fracture strength of 2 196 MPa and plastic strain of 4%

respectively.When the Co content is 7.5%

the fracture strength and plastic deformation rate are decreased rapidly from 2 196 MPa and 4%to 2 062 MPa and 1.5%

respectively.While increasing the Co content from 7.5%to 11.5%

the fracture strength is increased to 2 106 MPa

however the plastic deformation rate is reduced to less than 0.2%.