The Effect of Simple Shear Extrusion on the Texture and Porosity Content of Al/Al2O3 Composites

In this study, aluminum/alumina composites with 1 and 3 vol% reinforcement particles were produced using powder metallurgy (PM); this was then followed by simple shear extrusion (SSE). Three SSE inserts with different distortion angles (α) were used in the SSE equipment. Three pressure values of 400, 600 and 800 MPa were selected for powder compression. Additionally, three different temperatures of 530, 550 and 570°C were chosen to evaluate the suitable sintering temperature and achieve the optimal SSE process. The effect of post-sintering annealing treatment on SSE feasibility was also investigated. In addition, porosity was measured by the Archimedes method and the microstructure of samples was evaluated using optical and scanning electron microscopy. Evaluation of the crystalline texture was examined by the X-ray method. It was found that the pressure of 800 MPa was the optimal value for the cold compression of powders and the temperature of 570℃ was the best sintering temperature. It was also observed that the temperatures 400℃ and 450℃ had no effect on increasing the number of SSE passes. Porosity of the Al-3 vol% alumina sample was changed from 5.75% to 5.02% after three SSE passes with α=10°. A preferred crystallographic texture was not seen due to the amount of effective strain and the presence of micro-pores, but a very low intensity cube texture {001} <100> was seen in some regions.

The Effect of Simple Shear Extrusion on the Texture and Porosity Content of Al/Al2O3 Composites Keywords:

Powder metallurgy technique , Simple Shear Extrusion , Porosity measurement , Crystallographic texture , Aluminum/alumina composite