Ti14合金半固态下的氧化行为研究

Research on Semi-Solid Oxidation Behavior of Ti14 Alloy

半固态氧化温度升高,氧化增重急剧增加。Ti14合金经半固态氧化后,氧化皮仅为TiO2,不存在任何形式的Cu的氧化物,这是Cu的氧化物挥发的结果。1050℃后,因为CuO的挥发,导致增重有降低的现象。Ti14合金半固态氧化后,氧化层分为3个层次,最外层为疏松的TiO2(在1100℃以上时已经基本脱落);次外层为比较致密的TiO2和Al2O3,该层以Al2O3为主;再次层由较疏松的TiO2及Cu的氧化物组成,该层中以TiO2为主。Ti14合金半固态氧化后,因为低熔点相Ti2Cu的存在,熔化晶界成为氧向基体扩散的优先通道。半固态下钛合金不具有任何抵抗氧化的能力。

The semi-solid oxidation behavior of Ti14 alloy was researched.The results showed that the weigh gain increase obviously with the increasing of the semi-solid oxidation temperature . After semi-solid oxidation,the components in the oxidation scales is only TiO_2 and there are not any oxides of Cu .That is the result of the evaporation of CuO . The evaporation of CuO over 1050℃ results in the decrease of the weight grain . Analysising of the results of the semi-solid oxidation of Ti14 alloy, we can draw a result . The oxidation layer consists of three regions ;a loose TiO_2 region is the top layer which has been ablated over 1100℃; the secondary layer consists of compact TiO_2 and Al_2O_3 which is the main part ; the thirdly layer consists of loose TiO_2 and the oxide of Cu and TiO_2 is the main part. Because of the existence of the low-melt point-phase (Ti_2Cu),the melting grain boundaries become the preference walkway for the diffusion of oxygen . The titanium alloys have not any resist oxidation capabilities under the semi-solid conditions.