Experimental and Numerical Investigation of Process Parameters on the Residual Stresses in the Al-Cu FGM Materials

Functionally gradient materials (FGM) are new materials that can offer different properties depending on the structure. In this study, two aluminum and copper powders were combined together by the rules of FGM materials. When two different materials are combined in the structure of the FGM, due to the difference in the thermal expansion coefficients of these two materials, residual stresses are created in the sample. The results of residual stresses measurement were compared with done studies in the past as well as their results. Due to the compressive nature of the FGM manufacturing operations, the measured results show the creation of compressive residual stresses in the structure of the constructed samples. The obtained maximum amount of residual stress from the experimental sample was 130 MPa. Also, a finite element model (FEM) was used to evaluate the residual stresses in the structure of the FGM. The experimental measurements were validated by finite element simulation, which presented a good agreement with an error of 4%. Finally, the effects of pressure values in the powder pressing, layout and heat treatment temperatures were investigated by the FEM.