Evaluation of Alternative Parameters to describe the Quality of Additively Manufactured Aluminium Alloy Surfaces

Recent developments in metal additive manufacturing offer new possibilities for various applications by enabling lightweight, biomimetic designs. Reductions in material waste and manufacturing process duration are viable. When qualifying additively manufactured metal parts, especially the surface quality is challenging. Characteristic for metal additive manufacturing surfaces are powder particle agglomerations, sub- surface voids and undercuts. The special nature of those surfaces cannot be described by means of commonly used surface parameters like arithmetic mean height (Ra / Sa) and maximum profile height (Rz / Sz, ISO 4287 and ISO 25178).Therefore, in this work, less common parameters described in the aforementioned standards are considered in order to find a set of parameters to characterize metal additive manufacturing surfaces. For selected aluminium alloys and a laser beam melting process, surface parameters obtained from a structured light scan were examined statistically. Furthermore, sample densities have been determined following Archimedes' principle. Ultimately, the aim is to find a set of parameters enabling a holistic description of additively manufactured metal surfaces and their characteristic features. The correlation of printing parameters with standardized surface parameters and results of alternative surface characterization methods as well as fatigue life are subject to further investigation.