Thermal stability and instrumented indentation in a Mg60Cu30Y10 bulk metallic glass

The crystallisation and mechanical properties of the light alloy, Mg60Cu30Y10 bulk metallic glass (BMG) have been investigated by differential scanning calorimetry and instrumented indentation. Generally, the low-temperature plasticity of BMGs can be improved by partial devitrification to give an ultra-fine crystal structure in the amorphous matrix. From the indentation tests, increases in hardness and elastic modulus were observed after both the first and second stages of crystallisation. Plastic instabilities have been observed in the instrumented-indentation loading curves, even for samples with a significant crystallised fraction.