Preparation and properties of 2D C_f/SiC-Cu composites produced by precursor infiltration and pyrolysis

In order to meet the working requirements of a solid rocket nozzle throat,the anti-ablative properties of 2D C_(f)/SiC composites have been improved by decreasing surface temperature by Cu boil-off in ablative conditions.2D C_f/SiC-Cu composites with different Cu contents(2.18 vol%,4.86 vol%,6.53 vol %) were prepared via precursor infiltration and pyrolysis,and their mechanical and ablative properties were investigated.Results indicated that with increasing Cu content,the flexural strength decreased from 261.07 MPa to(203.61 MPa) to 164.91 MPa,and the fracture toughness also decreased from 13.4 MPa·m~(1/2)to 12.5 MPa·m~(1/2) to(11.8 MPa·m~(1/2)).The composites all retained structural integrity after 30 seconds ablation in an oxyacetylene torch,but flexural strength decreased to 121.16 MPa to 140.23 MPa to 122.87 MPa,and the corresponding mass ablations were 0.036 g/s,0.050 g/s and 0.064 g/s.The 2D C_f/SiC-Cu composites have low density,high strength and low ablative loss compared with other throat materials.