Effect of surface cleaning on interface bonding performance for 316H stainless steel joints manufactured by additive forging

Abstract Additive forging is a newly developed method to manufacture heavy forgings by using multilayer hot-compression bonding. However, the relationship between surface cleaning and bonding performance of bonded samples in the additive forging process is unclear. This paper studies the effect of surface cleaning on interface bonding performance for the first time. A new characterization method of surface cleanliness consisting of water contact angles, relative fluorescence units, and optical observation was proposed to characterize the cleaning effect. The micromorphologies and tensile properties were used to evaluate interface bonding performance. Elemental analysis and morphological analysis were used to infer the hindrance mechanism of contaminants. The results show that the new characterization method can effectively characterize the surface cleanliness of substrates. Moreover, the interfacial bonding performance results indicate that surface cleaning had a great influence on the bonding performance for 316H stainless steel joints manufactured by additive forging. Finally, the hindrance mechanisms of particles, chips, and oil contaminants were attributed to the hindrance effect in a radial direction, along the interface direction, and perpendicular to the interface direction respectively. This research builds a relationship between surface cleaning and bonding performance, which helps achieve high-performance manufacturing of heavy forgings.