Analysis of effects of material mechanical properties on hydro-joining

Hydro-joining of assembled hollow camshaft is a new technology applicable for manufacturing hollow camshaft of automobile engine with different materials. The keys of the technology is reasonable materials match and proper hydro-joining pressure. Based on elastic-plastic theory, the effect of Young's modulus and flow stress on the hydro-joining was analyzed in order to provide theoretical basis for structure design and materials match of assembled hollow camshaft. Assuming the deformation of joined pairs as a plane strain model, the process of hydro-joining was analyzed with the stress-strain curves, consequently the joining conditions of different materials were presented. It is concluded that; the core factors in hydro-joining are Young's modulus and flow stress of joined pairs because of their crucial effects on elastic recovery of the joined pairs; a necessary condition for hydro-joining is that the ratio of Young's modulus of inner one to the outer one should be higher than the ratio of flow stress between them.