复杂形状钛管件内表面氧化铝涂层综合制备新工艺研究

Investigation on a New Combined Process of Preparing Al_2O_3 Coatings on Inner-face of TA1 Pipe-fittings with Complicated Shape

为提高钛管件的耐腐蚀性能及抗冲刷磨损性能,研究了在具有复杂形状钛管件内表面制备氧化铝陶瓷涂层的新方法。先通过爆炸焊接制备了Ti/Al双金属复合管,再将其成形为复杂管件,接着通过微弧氧化将复合管件的铝层进行陶瓷化处理,从而将铝层部分转化为氧化铝层。采用XRD、SEM对氧化铝层的相组成及形貌进行了分析,并对氧化铝层与基体的结合强度、耐腐蚀性能和耐冲刷性能进行了表征。结果表明:涂层主要由γ-Al2O3及α-Al2O3组成,其中γ-Al2O3的厚度约为40μm,α-Al2O3的厚度约为10μm;陶瓷涂层与基体结合力达55N,涂层腐蚀电流比钛基体降低5个数量级。另外,氧化铝陶瓷涂层可以有效地防护基体被冲刷。

A new combined process of preparing the A12O3 coatings on the inner surface of TA1 pipefittings with complicated shape was developed to improve the resistance of scouring abrasion and corrosion of substrate. The new process mainly included explosive welding, plastic forming and micro-arc oxidation. The phase composition and topography of A12 O3 coatings were investigated by X--ray diffraction（XRD）,scanning electron microscopy（SEM）,respectively. Bonding strength, corro sion resistance and anti scouring property of the coatings were also measured. The results indicate that the coatings are composed of ]＇--A12Oa and a-A12O3 with the thickness of 40/μm and 10/μm,respec- tively. The bonding strength can reach 55N between the prepared A12Oa coatings and TA1 substrate. The corrosion eurrent of coatings is 5 orders of magnitude lower than that of TA1 substrate. In addi tion,the Ale Oa coatings can protect substrate from scouring abrasion effectively.