POST-PROCESSING OF STIR CASTED Al-Si12Cu METAL MATRIX COMPOSITE BY FRICTION STIR PROCESSING

In the present study friction stir processing is applied on the stir casted metal matrix composite as a post-processing operation. Stir casted metal matrix composites are prepared by using zircon sand particles of 40 mu m in the matrix of Al-Si12Cu alloy. Friction stir processing is applied on the metal matrix plates at a constant rotational speed and traverse speed of 1400 rpm and 63 mm/min, respectively. Multiple passes of friction stir processing are applied to elucidate the effect of number of passes on microstructural modification. Microstructural examination showed a significant improvement in eutectic silicon morphology and distribution of zircon sand particles. After four passes of friction stir processing the zircon sand particles are reduced to similar to 5 mu m as compared to initial size of similar to 40 mu m. The friction stir processed metal matrix composite exhibited an increase in ultimate tensile strength, yield strength, percentage elongation, and hardness by similar to 90, similar to 104, similar to 300, and similar to 34%, respectively as compared to cast metal matrix composite.

Automated summary

Friction stir processing was applied as a post-processing operation on stir casted metal matrix composites using zircon sand particles in an Al-Si12Cu alloy matrix. Multiple passes of friction stir processing resulted in significant improvement in microstructure, reducing the size of zircon sand particles. After four passes, the metal matrix composite showed a significant increase in ultimate tensile strength, yield strength, percentage elongation, and hardness compared to the initial cast metal matrix composite.