PREPARING MULTI-COMPONENT HARD MATERIALS THROUGH SEVERE PLASTIC DEFORMATION

摘要

It is intended to prepare much harder materials with multi-elements or multi-components through friction stir processing (FSP) or accumulative roll bonding (ARB). The first trial is to add 1-10 volume percent nano ceramic particles into the soft AZ-series Mg alloys via four FSP passes. The H_v hardness of the resulting nano-composites reaches over 110. The second trial is to fabricate multi-element intermetallic alloys of Mg_(50-80)Al_(10-25)Zn_(10-40) by three FSP passes. The H_v hardness of the resulting intermetallic alloys varies from 140 to 350. The third trial is to prepare the nanocrystalline and/or amorphous Zr based alloys through room temperature ARB from various elemental foils. After 40-100 ARB cycles, the elemental foils are refined into nanocrystalline phases and eventually transformed into amorphous alloys. The H_v hardness varies from 200 to over 500. The characterizations of microstructures and mechanical properties of the resulting hard materials are presented.