渗铝温度对Ti_2AlNb合金高温抗氧化性能的影响  

Effect of surface aluminizing temperature on oxidation resistance of Ti_2AlNb alloy

作　　者：任蓓蕾[1] 缪强[1] 梁文萍[1] 王力[1] 胡荣耀 陆海峰[1] 

机构地区：[1]南京航空航天大学材料科学与技术学院,江苏南京211106

出　　处：《材料热处理学报》2015年第12期241-246,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51174119);南京航空航天大学博士学位论文创新与创优基金(BCXJ14-11);江苏高校优势学科建设工程资助项目

摘　　要：利用双辉等离子表面冶金技术在Ti_2AlNb合金表面制备渗铝层,借助SEM,EDS和XRD研究了3种工艺温度下(720,780和840℃)渗铝层的微观组织及其相组成,并测试了渗铝温度对Ti_2AlNb合金高温氧化性能的影响。结果表明:等离子渗铝层由沉积层和扩散层组成,随着渗铝温度的升高,扩散层厚度不断增加,且内部Al、Ti和Nb元素浓度呈梯度分布。经渗铝处理后的Ti_2AlNb合金在850℃空气中的氧化速度主要受扩散层Al元素与基体Ti、Nb元素之间的热扩散过程控制。氧化动力学曲线呈对数变化规律。在840℃制备的渗铝层具有最佳的抗高温氧化性能。Surface aluminized layers were fabricated on Ti_2AlNb alloy surface by double glow plasma technology at different temperatures（ 720,780 and 840 ℃）. The microstructure and phase composition of the layers were analyzed by SEM,EDS and XRD. The high temperature oxidation resistance of the layers prepared at different temperatures was tested. The results show that aluminized layer consists of compact deposited layer and Al,Ti and Nb diffusion layer. The thickness of the diffusion layer increases with the process temperature increasing,and the content of Al in the diffusion layer is gradually decreased. The oxidation velocity of the aluminized layers is controlled by the diffusion process of elements between the layer and the substrate at 850 ℃. The oxidation kinetics curves follow logarithmic change law. The aluminized layer prepared at 840 ℃ exhibits excellent high temperature oxidation resistance.

关 键 词：Ti2AlNb合金 双辉等离子表面冶金 渗铝 高温氧化 

分 类 号：TG174.4[金属学及工艺—金属表面处理]