Ti_3AlC_2循环氧化表面氧化膜的结构和结合强度

Microstructures and Adhesion of Oxide Scale Formed on Ti_3AlC_2 After Cyclic Oxidation

采用扫描电镜和超声-划痕法研究了Ti3AlC2在650～950℃范围抗循环氧化后的表面、截面形貌和膜基结合强度。结果表明:经历40次循环之后,Ti3AlC2在650℃存在反氧化现象;在750～950℃氧化动力学属于抛物线型,同时表面形成平坦、致密和无微裂纹的氧化膜,该氧化膜能够有效阻挡O的向内扩散以及Ti和Al的向外扩散,氧化膜和基体结合良好,并且出现分层现象,其结合强度均大于50mN。

The surface, section morphology and adhesive strength of anticyclic-oxidized Ti3 AlC2 were analyzed by SEM and ultrasound scratch method at 650-950℃. The results show that after 40-cycle oxidation the abnormal oxidation occurs at 650℃. At 750-950℃ the oxidation kinetics follows a para- bolic rate law and the flat, dense and microcrack-free oxide scales are formed which can effectively im- pedance the inner-diffusion of O and the outer-diffusion of Ti and AI, protect the substrate of Ti3 AIC2, well adhesive to the substrate and demixing, the adhesive strength is greater than 50mN.