Micro and nano indentation studies on Zr60Cu10Al15Ni15 bulk metallic glass

• Highest hardness is observed in the fully crystalline regions.
• Large atomic misfit between intermetallic phases provides additional hardening.
• A unique case of ISE is observed in both glassy as well as crystalline regions.

Partially vitrified Zr60Cu10Al15Ni15 bulk metallic glass has been synthesized using water cooled copper mold drop casting technique. Kinetically favorable microstructures having different morphologies are observed throughout the volume of the bulk metallic glass sample. X-ray diffraction studies indicate formation of hard intermetallic compounds such as Zr3Al2 and Zr2Ni in certain regions along with amorphous structures. Microindentation studies carried out in different regions of the sample reveal microstructure dependent deformation behavior. Highest hardness is observed in the fully crystallized regions compared to pure glassy regions in the same sample. Further nanoindentation in the same sample is used to understand dynamic mechanical properties of microstructures in different regions. The pile-up morphologies around the indent and differences in load–displacement curves provide vital information on deformation behavior of sample in different microstructure sensitive regions.