Study on compression forming of a rotating disk considering hybrid friction

Hybrid friction at the interface between die and circular disk is assumed, which indicates the Coulomb friction and the sticking friction are generated simultaneously at the contact zone. An analytical model of compression forming with consideration of the rotating effect is derived by the slab method. In this study, the effects of rotating angular speed of disk, ratio of diameter to thickness, coefficients of friction on compression characteristics are explored effectively. The limiting coefficient of friction is formulated so as to avoid the generation of hybrid friction. The analytical model can correctly calculate the compression pressure, the radial stress, the compression force and the position of radius at which the sticking friction occurs. This study utilises the analytical approach to establish a model of plastic mechanism. The characteristics of the rotating compression forming can be derived rapidly and effectively in this study and it is suitable for industry of compression forming.