激光热处理对7475铝合金阳极氧化膜表面-界面性能的影响

Effects of laser heat treatment on surface-interface properties of anodic oxidation film on 7475 aluminium alloy

利用阳极氧化法在7475铝合金表面制备一层氧化膜,通过激光热处理(LHT)对氧化膜进行改性处理,采用扫描电子显微镜(SEM)、能谱分析仪(EDS)、X射线衍射仪(XRD)分析氧化膜表面-界面形貌、化学元素分布和物相,并对其表面和结合界面化学元素进行面扫描和线扫描分析,研究激光热处理对氧化膜组织和性能的影响。结果表明:激光热处理后,7475铝合金氧化膜表面孔洞增多,界面形成致密热影响区;氧化膜主要由Al_2O_3和SiO_2组成,而热影响区主要由Al_2O_3组成;Al、O、Si原子在结合界面发生富集现象,其界面为化合物型+扩散型形式。

A layer of oxide film was prepared on the surface of 7475 aluminum alloy by anodic oxidation, which was strengthened with laser heat treatment(LHT), the surface-interface morphologies, chemical element compositions and phase were analyzed by scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), X-ray diffractometry(XRD), respectively, and the chemical elements of the surface and bonding interface were analyzed with plane scan and line scan, respectively. The results show that the number of pores increases on the 7475 aluminum alloy oxide layer surface, and the dense heat affected zone forms at the interface after LHT. The oxide layer is mainly composed of Al_2O_3 and SiO_2, the heat affected zone is mainly composed of Al_2O_3. The hierarchical enrichment phenomenon of Al, O and Si atoms at the binding interface is produced after LHT, the bonding of compound type + diffusion type forms at the interface.