Abstract
Surface cracking or delamination of the top ceramic layer in metal/ceramic graded powder compacts is one of the problems when functionally graded materials are fabricated by sintering. To reduce the internal stress in powder compacts during sintering, uniaxial pressing by weights is studied. Change in stress distribution due to compressive loads is analyzed by the finite element method for sintering. Non-uniform sintering shrinkage in the powder laminates produces in-plane tensile stress on the top surface, which consists of the mismatch stress and the bending stress. Uniaxial pressing is effective in reducing the tensile bending stress on the top surface when the powder laminates warp downward. The axial tensile stress around the edge of the laminates, which may be the cause of delamination, can be also decreased by pressing.
