Enhanced mechanical behavior and texture development of Al/Al2O3 composites produced by spark plasma sintering (SPS) and vacuum hot pressing (VHP) followed by simple shear extrusion (SSE)

Abstract

Green compacts of Al-3vol% Al2O3 composites were produced by powder metallurgy (PM) and subsequently processed by spark plasma sintering (SPS) and vacuum hot pressing (VHP). The manufactured samples were then processed by the simple shear extrusion (SSE) process. Three SSE dies with the distortion angles (α) of 8°, 10° and 22.5° were used in this study. The SPS-ed/SSE-ed specimens for α = 10° were successfully deformed up to sixteen passes, while the VHP-ed/SSE-ed samples failed after six passes. In addition, the SPS-ed sample for α = 22.5° only underwent one pass of SSE. The SPS-ed/SSE-ed composites resulted in the highest shear punch test (SPT) load, modified porosity amount and the best reinforcement redistribution, as compared to the vacuum sintering and stir-casting manufacturing methods, which was confirmed by microstructure evaluation and porosity measurements. The crystallographic texture of the SPS-ed/SSE-ed composites for α = 10° was investigated in the sixteenth pass using the X-ray method. The results of texture development showed the very low intensity of shear and cube texture with {100} and {001} components, subsequently.

Keywords

• Simple shear extrusion (SSE)
• Spark plasma sintering (SPS)
• Vacuum hot pressing (VHP)
• Shear punch test (SPT)
• Porosity measurement
• Texture development