Influence of Si on glass forming ability and properties of the bulk amorphous alloy Mg60Cu30Y10

We studied the influence of partially replacing Cu by Si in the bulk amorphous alloy Mg30Cu30Y10. Glass forming ability (GFA), examined using X-ray diffraction and a differential scanning calorimeter, was increased at 1% Si, but decreased for larger Si concentrations. Nano-indentation measured nano-hardness, elastic modulus and load–displacement curves. The elastic modulus and nano-hardness increased with increasing Si content to a maximum at 2.5%. The load–displacement curves during nano-indentation revealed displacement serrations. These increased with decreasing loading rates, decreased with increasing Si content. The load–displacement curves also indicated that these bulk amorphous alloys exhibited primary creep at room temperature just like other high strength alloys. The creep displacement decreased with increasing Si content.