Interface structure and properties of a brass-reinforced Ni59Zr20Ti16Si2Sn3 bulk metallic glass composite

Interfaces between a Ni59Zr20Ti16Si2Sn3 bulk metallic glass (BMG) and crystalline brass reinforcements were characterized using transmission electron microscopy and nanoindentation. An interfacial layer with a thickness of ∼50–100 nm was observed in the composite prepared by warm extrusion of gas atomized powders. Microstructural characterization and chemical analysis suggest that the formation of interfacial layer was caused by interdiffusion between the BMG and brass during the warm extrusion. Nanoindentation in the vicinity of BMG–brass interfaces does not cause interface decohesion or crack formation, suggesting a strong interface bonding. Apparently, the resultant interfacial layer not only enhances interfacial bonding but also provides a buffer zone to prevent the catastrophic shear band propagation in the BMG matrix.