摘要:
The direct-current simulation burning method was used to investigate the burn-resistant behavior of Ti14 titanium alloy. The results show that Ti14 alloy exhibits a better burn resistance than TC4 alloy (Ti–6Al–4V). Cu is observed to preferentially migrate to the surface of Ti14 alloy during the burning reaction, and the burned product contains Cu, Cu
2O, and TiO
2. An oxide layer mainly comprising loose TiO
2 is observed beneath the burned product. Meanwhile, Ti
2Cu precipitates at grain boundaries near the interface of the oxide layer, preventing the contact between O
2 and Ti and forming a rapid diffusion layer near the matrix interface. Consequently, a multiple-layer structure with a Cu-enriched layer (burned product)/Cu-lean layer (oxide layer)/Cu-enriched layer (rapid diffusion layer) configuration is formed in the burn heat-affected zone of Ti14 alloy; this multiple-layer structure is beneficial for preventing O
2 diffusion. Furthermore, although Al can migrate to form Al
2O
3 on the surface of TC4 alloy, the burn-resistant ability of TC4 is unimproved because the Al
2O
3 is discontinuous and not present in sufficient quantity.