Structure evolution and ablative mechanism of C/C-ZrC-ZrxCuy composites with low porosity fabricated by pressure assisted reactive melt infiltration

C/C-ZrC-Zr x Cu y composites were fabricated by pressure assisted reactive melt infiltration (PARMI). The infiltrated matrix contained three different ZrC-Zr x Cu y regions due to the gradient distribution of carbon and Cu during PARMI, and the dimensions of ZrC particles decreased sequentially from matrix boundary to inside. During 30 s ablation, heat-absorbing effect of Cu-phase slowed down the increasement of surface temperature. After 60 s ablation, porous ZrO 2 skeleton evolved to a protective integrated cover, including expanded large-scale infiltrator and network of curly whiskers. Thus, ablation rates of composites were reduced to -1.7 ± 0.1 μm/s and 1.7 ± 0.1 mg/s, separately. • The pressure assisted reactive melt infiltration method reduces porosity of C/C-ZrC-Zr x Cu y composites. • ZrC particle size and Zr x Cu y species display gradient variation in infiltrated ZrC-Zr x Cu y matrix. • The Cu-phase and ZrO 2 have a complementary enhancement to the anti-ablation property of composites. • Hollow ZrO 2 wiskers on surface can evolve into a network structure during long-term ablation.