Finite element design of MgO/Ni system functionally graded materials

Finite element analysis method was used to simulate the thermal residual stresses generated in MgO/Ni system functionally graded composites during post-sintering stage. All the material properties used for these calculations were obtained experimentally from the non-graded composites, their sintering behaviors, the mechanic and thermal properties were measured at 20% MgO volume fractions interval. A finite element numerical model and the compositional distribution optimization formulation were proposed for MgO/Ni functionally graded materials, the thermal stress distributions inside the graded layers and the MgO ceramic layer were calculated as a function of the composition distribution exponents. The maximum normal stresses developed in the Ni-rich region and released to the lowest level when P was equal to 1.8. The maximum radial and hoop tension released to the lowest level when P was equal to 1.6. The optimum composition distribution exponent P was 1.1 on the consideration of both material strength and the thermal stresses.