The critical role of heating rate in enabling the removal of surface oxide films during spark plasma sintering of Al-based bulk metallic glass powder

摘要

Metallic glass powder of Al_(86)Ni_6Y _(4.5)Co_2La_(1.5), prepared by nitrogen gas atomization, was consolidated into 10 mm diameter bulk metallic glass (BMG) samples using spark plasma sintering (SPS). The use of a high heating rate is critical to ensure oxide-free, well-sintered clean interfaces between the powder particles and therefore desired mechanical properties, compared to oxide-enveloped, poorly-sintered interfaces that result from the use of a slow heating rate. The marked influence of heating rate is attributed to the surface-cleaning effect of SPS associated with the increased electrical discharge.