Temperature-dependent mechanical behavior of aluminum AM structures generated via multi-layer friction surfacing

Multi-layer friction surfacing (MLFS) is a solid state layer deposition technology for metals. In order to make use of the potential of MLFS as technology for additive manufacturing, the material properties of MLFS built structures have to be investigated and understood in detail. This study presents a comprehensive analysis of the mechanical properties of MLFS deposited material from micro-flat tensile testing (MFTT) at elevated temperatures. The specimens obtained from the fine-grained MLFS structures show a slightly higher tensile strength at room temperature but lower tensile strength at testing temperatures of 300 °C and above compared to the stud base material. No significant gradient along the MLFS structure could be observed in terms of mechanical properties. The analyses of fracture surfaces and microstructure of tested MFTT specimens provide insights to deformation mechanism of MLFS deposited and consumable stud material. Especially at high testing temperatures of 500 °C, MLFS deposited structure shows abnormal grain growth which results in the observed tensile behavior.