Micro-failure mechanism of components via scaling method

Abstract

Accurately identifying microscopic failure mechanisms is essential for the safety of transportation systems. However, traditional methods, constrained by component macrostructures, often rely solely on material properties to evaluate performance, leading to potential inaccuracies in failure analysis. This paper proposes a novel macro/micro-scale component scaling method (MMCSM) to maintain micro-failure mechanism consistency before and after scaling. A diesel engine cylinder partition is used as a case study, where failure mechanisms are explored through the equivalent part obtained via MMCSM, coupled with microstructural characterization and simulation. Results reveal significant deviations from prior studies that considered only material properties, which suggested brittle fracture mechanisms. The equivalent part's macrostructure modifies internal micro-stress fields, yielding critical observations: (i) cracks are forced to propagate along a tortuous path within the matrix over an extended distance, and (ii) the direction of the maximum energy release rate (G) near the graphite phase shifts toward the matrix side. Thus, the graphite/matrix interface remains intact, transitioning the failure mechanism from brittle fracture to ductile fracture dominated by plastic deformation, thereby enhancing fatigue resistance. This approach bridges the macro and micro domains of components, providing insights into true failure mechanisms and contributing to the safe operation of engineering components.