Keyword: «aluminum alloy»

Solving the urgent problems of finding reliable methods for the early detection of damage in metal products and improving the accuracy of predicting their fatigue durability requires a deep understanding of the material's structural changes at different loading stages. The method of statistical analysis of microhardness was used to study the structural inhomogeneity and damageability of three zones of the aluminum alloy AD33, which failed during operation in the North, characterized by different degrees of low-cycle fatigue development. It is shown that the failure of the alloy is preceded by progressive structural inhomogeneity and a deviation of the microhardness distribution from Gaussian. Quantitative characteristics for the critical state of the alloy before failure have been established: the coefficients of structural inhomogeneity, damage accumulation, and the reduced sampling frequency increase by 3–4 times with a catastrophic 26% decrease in the average microhardness value.