Tangential adhesive force increaseswith the value of m for each element. However, the differences are small. While, the normal pressure provided by viscous medium also increases with the value of m. The increase of normal pressure results in the increase of frictional force at blank/die interface. The frictional force hinders the die cavity filling. When the value of m exceeds 0.15, the frictional force increases dramatically. Thus the influence of tangential adhesive force on metal flow is weakened markedly.
Tangential viscous adhesive force of a single element in zone C.