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-6A1-4V).Cu...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-6A1-4V).Cu is observed to preferentially migrate to the surface of Ti14 alloy during the burning reaction,and the burned product contains Cu,Cu2O,and TiO2.An oxide layer mainly comprising loose TiO2 is observed beneath the burned product.Meanwhile,Ti2Cu precipitates at grain boundaries near the interface of the oxide layer,preventing the contact between O2 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 O2 diffusion.Furthermore,although A1 can migrate to form A12O3 on the surface of TC4 alloy,the burn-resistant ability of TC4 is unimproved because the Al2O3 is discontinuous and not present in sufficient quantity.展开更多
基金supported by the Major State Basic Research Development Program of China(No.2007CB613807)the National Natural Science Foundation of China(Nos.51201019 and 51401033)
文摘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-6A1-4V).Cu is observed to preferentially migrate to the surface of Ti14 alloy during the burning reaction,and the burned product contains Cu,Cu2O,and TiO2.An oxide layer mainly comprising loose TiO2 is observed beneath the burned product.Meanwhile,Ti2Cu precipitates at grain boundaries near the interface of the oxide layer,preventing the contact between O2 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 O2 diffusion.Furthermore,although A1 can migrate to form A12O3 on the surface of TC4 alloy,the burn-resistant ability of TC4 is unimproved because the Al2O3 is discontinuous and not present in sufficient quantity.