Analysis of ablation properties of piston of Al₂O₃ fiber reinforced Al-Si alloy composite material

In order to assess ablation properties of Al-Si piston alloy reinforced with Al₂O₃ fiber, the ablation behaviors of Al₂O₃ fiber and Al₂O_3f/Al-Si composites were investigated. An ablation model was developed based on the ablation mechanism of the materials. The ablation behaviors of Al-Si alloy and composite were analyzed using the finite element model of piston. Results reveal that Al₂O_3f/Al-Si composites exhibit higher ablation properties and maintain its structural integrity under the high temperature and speed airflow, which are contributed by the dense structure and high yield strength at high temperature of the composites. The experimental observations indicate that the line ablation and mass ablation of the composites are little. Ablation mechanisms of the Al₂O_3f/Al-Si composites are melting ablation and gas flow erosion. Under the same environment, Al₂O_3f/Al-Si composites are the ideal anti-ablation material for piston. The experiments are simulated and predicted by the developed ablation model. Computational results agree with experimental data reasonably.