アルミニウム合金–樹脂異種材料接合部材の疲労特性に及ぼす各種陽極酸化処理の影響

抄録

In this study, to investigate the fatigue properties of joints between aluminum alloys and resins, we fabricated adhesive joints of A5052 aluminum alloy and injection-molded joints between A5052 aluminum alloy and polyphenylene sulfide (PPS) resin. Then, we examined the effects of various anodizing treatments on their fatigue properties. The anodizing process employed sulfuric acid anodizing (SA), phosphoric acid anodizing (PA), and a two-step anodizing process involving PA followed by SA (PA＋SA). For adhesive joints, the adhesive strength was highest for PA＋SA, followed by PA, and then SA. On the other hand, the fatigue strength remained the same regardless of the type of anodizing treatment. This is because the improved bond strength at the interface between the coating and the adhesive caused the fatigue crack to propagate through the adhesive, making the fatigue strength of the adhesive the dominant factor. In injection-molded joints, PA and PA＋SA exhibit superior joint properties compared to SA in terms of both joining strength and fatigue strength. It has been suggested that the fatigue properties of injection-molded joints depend on the strength of the joint interface.