Microstructure and Mechanical Properties of [(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4 Bulk Metallic Glass Compacts

摘要

In the present study, we report the relative density, microstructure and deformation behaviour of [(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4 bulk metallic glass (BMG) compacts. The compacts were prepared by melt spinning of alloy to get amorphous ribbons followed by mechanical milling to obtain powder and then sintering using spark plasma sintering equipment at different processing temperatures and pressures. Higher sintering pressures and higher sintering temperatures within the supercooled liquid region were found to be beneficial for obtaining high relative densities in Fe-BMG. However, increasing the sintering temperature was found to result in crystallization. Amorphous compacts of 99.5 % relative density were successfully obtained through SPS of amorphous powders, using a pressure of 650 MPa, temperature of 520 °C and holding time of 5 min. The compaction in SPS was attributed to the deformation of the individual particles because of the high temperature and pressure. The fracture strength and strain of the compact with 99.5 % relative density during quasi static compression test was found to be 2.7 GPa and 0.1, respectively. An interrupted compression experiment revealed the formation of numerous shear bands.