Gradient optimization of transversely graded Ti-TiB structures for enhanced fracture resistance

Metal-ceramic functionally graded materials (FGM) represent a class of composites in which the variation of ceramic (or metallic) content over a definable geometrical length can lead to a combination of desirable physical, mechanical, and thermal properties. These materials are often processed in high-temperature conditions. The asymmetric and variable thermo-physical properties along gradient directions in metal-ceramic FGMs lead to the development of process-induced residual stresses. Since these materials are primarily used as load-bearing components, the processing-induced residual stresses can be superimposed on in-service stresses and lead to premature failure. The present study aims to analyze the concurrent effects of gradation on processing-induced residual stresses and the fracture response of cracked transversely graded structures, that are FGMs with gradients parallel to the crack front. The analytical approach proposed in this work facilitates the identification of optimal gradients that lead to enhanced strength and fracture resistance.