Germany

A Review of Metal Fabricated with Laser‐ and Powder‐Bed Based Additive Manufacturing Techniques: Process, Nomenclature, Materials, Achievable Properties, and its Utilization in the Medical Sector

“…The common simplification of the directional dependencies is that the highest tensile strength, as well as ductility, occurs in a parallel layer to applied load scenario (Φ ¼ 0 ). [71,95,162] Opposed to this, the lowest results are represented by the perpendicular layer to loading scenario (Φ ¼ 90 ). One of the major arguments for this particular formulation is based on the increasing likelihood of the occurrence of irregularities and voids with an increasing number of layers.…”

“…Delicate samples, for example structures comprised of thin struts, revealed overall a lower strength and ductility, even a lower Young's modulus, compared to bulkier samples. [71,125,232] Almost stable properties were documented past a diameter size of 3-5 mm. Likewise to conventional bulk material, machined samples were found to show better mechanical properties, documented studies suggest an strength increase of 5-11% due to the removal of the surface, but also due to the removal of the increased pore density in the transition zone between the contour and core irradiation.…”

“…In recent studies, it was attempted to obtain the material constants of the linear elastic range, namely Young's modulus and Poisson's ratio, based on varying sonic velocities determined by ultrasonic investigation. [64,71] However, the reported results differ: In the case of an AlSi alloy, the reproduction of the values Table 3. Achievable relative densities for Fe-based raw materials.…”

“…This approach was also found to result in higher strength and ductility in delicate structures. [71] During the manufacturing process itself, the part is produced in a stepwise manner by selectively exposing successive powder layers, following the scan vectors with a laser beam as the driving force for localized solidification (see Figure 3). [44,55] After finishing the exposure of one single layer, the substrate plate is lowered and a new powder layer is added on top by an inbuilt recoater system.…”

“…Material Significance Reference 1.4404 contrary to the common simplification; maxima for both the tensile strength and breaking elongation at Φ ¼ 90 , minima for the strength at Φ ¼ 0 ; influence of the in-plane alignment (Θ) is negligible [127] AlSi12 Inconel 939 contrary to the common simplification; maxima for both the tensile strength and breaking elongation at Φ ¼ 90 [220,234] 1.4404 minima for both the tensile strength and breaking elongation at Φ ¼ 75 and their maxima at Φ ¼ 15 [237] 1.4404 Nimonic 263 maxima for the breaking elongation at Φ ¼ 90 [71,210] 1.4307 minima for the tensile strength at Φ ¼ 45 [159] AlSi10Mg minima for the tensile strength at Φ ¼ 45 , minima for the breaking elongation at Φ ¼ 90 , maxima for both at Φ ¼ 0 [91] 1.4404…”