FRICTION WELDING OF Zr55Al10Ni5Cu30 BULK METALLIC GLASS

As a new kind of engineering material, the metallic glass can be used widely due to its excellent properties such as high strength, hardness and elastic energy and low corrosion resistance. The size of metallic glasses is generally small, which is the main limitation for their application. How to prepare a larger size metallic glass becomes one of main targets in metallic glasses research. To prepare larger size metallic glasses, one method is to optimize their chemical compositions, and another is to join small size metallic glasses together by welding. In this paper, the Zr55Al10Ni5Cu30 bulk metallic glass (BMG) has been successfully jointed by friction welding under the conditions of rotational speed from 4×103 to 5×103 r/min, friction pressure from 80 to 100 MPa, friction time from 0.2 to 0.4 s, upsetting pressure 200 MPa and upsetting time 2 s. The welded joint has been examined using SEM, XRD and TEM, and it is proved that the welded zone still keeps an amorphous structure. The plasticity of this metallic glass has strong temperature sensitivity near the glass transition temperature Tg. Above Tg, the metallic glass possesses a good plasticity which is necessary for friction welding of metallic glasses.