Effect of strain path change on mechanical properties and final microstructure of Cu–Al2O3 in equal channel angular pressing

Abstract

In the present work, the process of equal channel angular pressing of dispersion strengthened Cu–1·1 wt-%Al2O3 containing nanometric alumina particles was investigated by means of mathematical modelling and experimental testing. Through the modelling, deformation parameters such as hydrostatic pressure distribution and strain field were determined, and the effect of deformation path on these parameters was estimated. Equal channel angular pressing as well as mechanical and microstructural evaluations were also conducted to assess mechanical properties, grain structure and void volume fraction after deformation in different routes. The results indicate that distributions of plastic strain and hydrostatic stresses are significantly affected by deformation path route as well as utilised die design. Furthermore, void formation around hard alumina particles may occur in regions with high tensile hydrostatic stresses leading to fracturing during deformation.