摘要
采用电弧喷涂技术对压铸AZ91D镁合金表面喷涂纯铝。为了提高其界面性能,对喷涂后样品在300℃、350℃、400℃和437℃分别进行1 h、5 h和10 h扩散热处理,并通过扫描电镜(SEM)、能谱仪(EDS)、X射线衍射(XRD)、及电化学分析仪测试了其界面的微观结构和性能。结果表明:在<400℃的温度下进行热处理时,其界面形成β-Mg_(17)Al_(12)相扩散层,并伴有少量γ-Mg_2A_(13)相,且扩散层厚度随保温时间的延长而增大。在温度≥400℃,保温时间较短时(1 h和5 h),界面生成γ一Mg_2A_(13)相和β-Mg_(17)Al_(12)相两个扩散层,当保温时间延长至10 h时,扩散层演变成了β-Mg_(17)Al_(12)单相层和α-Mg+β-Mg_(17)Al_(12)复合相层。相对AZ91D基体而言,各种冶金扩散层的耐腐蚀性能都有明显增强,特别是两个单相扩散层。
Al coating was prepared on the surface of die-casting AZ91D Mg alloy through electro-arc spraying technology. In order to enhance the performances of the interface,the samples were heat treated at 300 ℃ ,350 ℃ ,400℃ and 437 ℃ for 1h,5 h and 10 h after spraying,respectively.The microstructures and properties were charactered by the means of XRD,scanning electron microscope （SEM）,energy-dispersive spectrometry （EDS）,and electrochemical analyzer. The results show that β-Mg17Al12 phase diffusion layer appears at interface when the annealing temperature under 400 ℃, and a little γ-Mg2A13 phase accompanied, and the more annealing time, the thicker diffusion layer. When the annealing temperature is over 400 ℃,γ phase layer and β-Mg17Al12 phase layer appears for short annealing time （1 h,5 h）,the microstructure of diffusion layer becomes 13 phase and a＋β dual-phase layer for 10 h. Comparing the Mg alloy substrate, the corrosion resistance of the diffusion layer is obviously increased, further, the single-phase （β） diffusion layer is better than dual-phase （a＋β） diffusion layer.
出处
《铸造设备与工艺》
2016年第1期25-29,共5页
Foundry Equipment & Technology
基金
太原科技大学校博士科研启动项目(20152011)
国家自然科学基金资助(51044007
51374151)
中国博士后科学基金(20100471586)
关键词
压铸AZ91D镁合金
电弧热喷涂
扩散热处理
微观结构
性能
die-casting AZ91 D, electro-arc spraying, diffusion heat treatment, microstructures, performances
