Abstract
Systematic low-cycle fatigue (LCF) experiments are carried out on additive manufactured AlSi10Mg specimens for several material conditions with varying layer thickness, heat treatment, building direction and surface quality. The deformation behaviour depends significantly on the heat treatment. It is outlined that the process control and heat treatment can produce fatigue properties comparable with the cast material, whereby an as-built specimen surface leads to a lifetime reduction in all cases. The experiments are accompanied with detailed metallo- and fractographic investigations. For all tested LCF specimens, the defect type and the failure origin defect size are characterized in terms of the √area parameter by using scanning electron microscopy. The failure of the specimen is mostly caused by lack of fusion surface or near-surface defects, whereby the defect size is determined by the SLM process parameters, such as building direction, surface quality and layer thickness. On the basis of the experimental data and the observed defects, a mechanism-based, deterministic lifetime model is developed and adapted to the specific damage mechanisms of the additive manufactured AlSi10Mg alloy.
Highlights
The selective laser melting (SLM) process stands at the beginning of a major development for many medical and aerospace applications and in many other sectors of industry [1]
The failure of the specimen is mostly caused by lack of fusion surface or near-surface defects, whereby the defect size is determined by the SLM process parameters, such as building direction, surface quality and layer thickness
In addition to the results shown in figure 4, further low-cycle fatigue (LCF) tests with mechanical strain amplitudes of εma ech = 0.3 % and 0.4 % are performed
Summary
The selective laser melting (SLM) process stands at the beginning of a major development for many medical and aerospace applications and in many other sectors of industry [1]. The primary objective in the qualification of additive manufactured materials is to achieve the optimum in component density [4, 5] For this purpose, a wide matrix of parameter sets are systematically studied to obtain the lowest-possible porosity [4, 6]. Th√e large material scatter in HCF results is assessed with area and extreme value statistics, where the defect population and defect size distribution of whole specimens are applied by computer tomography scan measurements in order to predict lifetimes and the failure probab√ility of additive manufactured AlSi10Mg [15, 16]. With the obtained material parameters from the LCF tests and the initial defect sizes, the lifetimes are assessed using a mechanism-based deterministic lifetime model
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
