Plastic Deformation and Densification Behavior By Different Sheath Materials in Molybdenum Powder Forging

Finite element method (FEM) was used to investigate the plastic deformation and densification for porous molybdenum in isothermal canned forging. Separate simulations were performed using different sheath materials: 45 steel, 304 stainless steel and GH4169. The simulations demonstrate that the distributions of strain, density and average stress strongly depend on the sheath materials. The distributions of density and strain present the shape of “U”. The density and strain, increase with increasing strength for sheath materials at the same levels of deformation. The homogeneity of strain and density are best in billet encapsulated with the 304 stainless steel when the deformation extent exceeds 40%. The average stress decreases linearly with the increasing distance from center except for small area near the edges. Among the three materials, the 304 stainless steel is the most suitable materials as sheath during isothermal canned forging of porous molybdenum.