Pore tracing in additive manufactured and hot isostatic pressed components

Abstract

Despite past scientific efforts and the increased use of hot isostatic pressing (HIP) in additive manufacturing applications, a complete understanding of the exact pore-closing behaviour has yet to be achieved. The present research focuses on laser powder bed fused (LPBF), hot isostatic pressed components made of AlSi10Mg, and process-related defects. The study shows the effect of HIPing in relation to various pore characteristics, such as pore shape, size, and type. A pore tracing method using X-ray data was developed to characterise the pores before and after HIP. The method is based on the k-nearest neighbours approach and allows to match leftover pores with the initial ones. Hence, the efficiency of the pore-closing behaviour for different HIP settings can be analysed. Moreover, the exact number of pore transformations can be tracked, providing a comprehensive insight into the change of pore characteristics during HIP. In this framework, eight different HIP settings and a total number of 274,886 pores were examined and discussed.