LAUSR

Abstract Small solid rocket motors (SRM) require low density, low ablation nozzle-throat materials. In the present study, Al20Si alloy was infiltrated into the porous graphite matrix to develop Al20Si/graphite composites by pressure infiltration method. The ablation behavior of the as-prepared composite was investigated in a small SRM testing system with an average pressure of 13.3 MPa and 5 wt% Al for 1.4 s. The results show that the linear ablation rate of the Al20Si/graphite throat decreased by 92% compared to that of the C/C composite throat. The increased anti-ablative properties are provided by Al20Si alloy fillers, which reduce the degree of thermochemical ablation of the graphite matrix through heat dissipation, oxygen dissipation, and thermal blockage. Furthermore, the Al4SiC4 generated from Al20Si alloy and graphite fills graphite pores, which contributes to the oxidation resistance of the composite.