Experimenteel en numeriek onderzoek naar het fretting-vermoeiingsgedrag van additief vervaardigde metalen onderdelen

Additive manufacturing (AM) is becoming a game-changing technology withenormous potential impact on the range of available designs, enabling newcomponent capabilities that cannot be realized with any other technology andreducing lead-times, storage and transportation costs. Among different available AM technologies, Selective Laser Melting (SLM) is a powder-bed basedtechnique which is very popular. The successful construction of additively manufactured metallic components for safety-critical applications requires athorough understanding of metallurgical structures, residual stresses and associated mechanical properties. Fatigue fracture assessment of SLM components is well-documented in the literature. However, there is very little research work focusing on tribo-mechanical properties of SLM components, such as fretting fatigue phenomenon. By definition, the fretting fatigue occurs when two contacting parts slip over each other at a micro level while being subjected to an external fatigue loading conditions. When compared to a plain fatigue problem, fretting fatigue reduces the lifetime of a part by half. This phenomenon is a complicated task, because of the fact that the contact stresses at the contact interface are multiaxial. To this end, depending on the multiaxiality and non-proportionality of the stresses at the contact interface, the response of the material is different. This failure mode happens in many industrial applications such as automotive parts, fasteners, bearings shafts, steam and gas turbines' blades. Many of these applications such as steam and gas turbines' blades are potential applications for AM technology. Therefore, correct assessment of the fretting fatigue response of additively manufactured parts is very important for safety-critical applications such as gas turbines' blades. This research project focuses on behaviour of additively manufactured metal parts when subjected to the fretting fatigue loading conditions using both experimental testing and advanced numerical modelling.