Ablation behaviour of titanium diboride-copper-nickle FGM

TiB₂-Cu-Ni five-layer metal-ceramic functionally graded material (FGM) was produced by self-propagating high-temperature synthesis (SHS) under the conditions of pseudo hot isostatic pressing (PHIP). The microstructure and composition of the FGM before and after test were examined by SEM and EPMA etc. The FGM was heated for 20 seconds by plasma torch arc heater to investigate thermal shock resistance and ablation behaviour. The results show that the stacked interface between layer and layer of FGM is obscure, which shows that the bonding between layer and layer is good. The FGM did not burst apart when the surface temperatures of FGM increased and went down drastically in a very short moment. Moreover, no apparent cracks were found on the ablation surface of FGM. These results show that the thermal shock resistance of FGM is excellent. The mass loss of FGM after ablation test is only 0.5 g, which shows that the resistance to ablation and erosion of FGM is good. The ablation mechanisms of the material are volatilization of metal binder, hot chemical ablation and mechanical erosion. This FGM can be used widely as nozzle and throat in the solid rocket motor.