Investigations on ablation for highly-intensified diesel engine piston material

Abstract

With the improvement of the degree of diesel engine enhancement, the thermal load of the piston is greatly increased, and higher requirements is imposed on the ablation resistance of the piston material. Three kind of piston materials were selected and the ablation performance was analyzed through experiments and simulation calculations, then the ablation mechanism and ablation model of piston materials were analyzed. Results revealed that Ablation mechanisms of piston material are melting ablation and gas flow erosion. Al-Si alloy materials have poor anti-ablative properties. Al2O3 f/Al-Si composites and aluminum borate whisker reinforced Al-Si matrix composites exhibited higher anti-ablation properties, which contributed by the dense structure and high yield strength at high temperature of the composites. Aluminum borate whisker reinforced Al-Si matrix composites has the best anti-ablative properties. Keywords: Diesel engine, Piston, Composite material, Micrograph, Ablative property