HfC-based coating prepared by reactive melt infiltration on C/C composite substrate

Reactive melt infiltration based on alloy design is proposed in the present work for preparing HfC-based coating on C/C composite substrate. A 50Hf10Zr40Si alloy ingot was prepared and infiltrated into a C/C preform at temperatures much lower than the melting point of the alloy to obtain the HfC-based coating. An obvious layered microstructure of the coating was formed. The carbonization reactions occurring between Hf and carbon of the surface layer of the C/C composite is the primary reason for the reactive melt infiltration process to proceed at relative low temperatures. Acetylene flame test showed that the HfC-based coating protected the C/C composite from serious oxidation.