Study on the formation of new Mg–Cu–Ti–Y quaternary bulk metallic glasses with high mechanical strength

Abstract New Mg–Cu–Ti–Y quaternary bulk metallic glasses (BMGs) with diameter of 2 mm have been designed and successfully fabricated by conventional copper mold casting method. The X-ray diffractometer (XRD) and differential scanning calorimeter (DSC) examinations indicate that the as-cast Ti-containing Mg 60 Cu 30 − x Ti x Y 10 ( x = 3, 5, 8 at.%) alloys possess completely amorphous structures and large supercooled liquid region (59–64 K). The mechanical property testings demonstrate that this kind of new BMGs also have high compressive fracture strength ( σ f ), big elastic strain ( e e ), high Vickers hardness (Hv) and low elastic modulus ( E ). Thereinto, the σ f , e e , Hv and E values of the as-cast Mg 60 Cu 27 Ti 3 Y 10 BMG sample reach up to 879 MPa, 3.04%, 347 and 34 GPa, respectively, which are much superior to the as-cast Ti-free Mg 60 Cu 30 Y 10 BMG. The as-cast alloys' fracture surface morphologies and dominant fracture behaviors have also been characterized and explained in detail.