Ti40和AlloyC在燃烧过程中的氧化界面分析

Burning Interfaces Analysis of Burn resistant Titanium Alloys Ti40 and Alloy C

摘要:

采用直流电弧激发燃烧法（DCSB法）测试Ti40,AlloyC和TC4合金在3种气氛条件下的相对质量燃烧速度。结果表明：与TC4合金相比，Ti40和AlloyC均具有较好的阻燃性能，用氮气来稀释空气能够降低钛合金的燃烧速率。用扫描电镜（SEM）与X射线能谱（EDAX）观察分析了合金的燃烧产物、界面与基体，发现：当Ti40和AlloyC燃烧时，V优先迁移至表层，因而燃烧区表层氧化层为富V贫Cr，而燃烧产物与基体界面附近氧化层则为富Cr贫V。Ti40与AlloyC界面的富Cr贫V混合氧化层非常致密，既可抑制氧扩散入基体，又可阻碍基体中的V扩散进入燃烧区。TC4燃烧时，虽然Al优先迁移至表面与氧反应生成Al2O3，但该氧化层不连续不能有效降低燃烧速度，Cr,V元素均对合金燃烧时界面氧化层的致密化有重要作用。

Abstract:

DCSB method is used to evaluate the burn resistant properties of Ti 40, Alloy C and Ti 6 4 three atmosphere conditions in this paper. The results show that Ti40 and Alloy C display good burn resistance as compared with Ti 6 4, and that the addition of nitrogen into air can decrease burning rate of titanium alloys. Burning interfaces were observed and analyzed by SEM and EDAX. It is found that which indicates that vanadium is preferentially immigrated to the surface to form V 2O 5 upon Ti40 and Alloy C burning. As a result the surface layer in burning zone is V enriched and Cr leaned, while the burned products and the oxidized layer close to matrix interface are V leaned and Cr enriched. The mixed oxidized layer is very dense, and can inhibite oxygen diffusion into the matrix, and prevent V in the matrix from diffusion into burning zone.Although Al can be preferentially immigrated to the surface to form Al 2O 3 upon Ti 6 4's burning, but it is too less in content to improve the alloy's burn proof ability.