Laser Powder Bed Fusion (LPBF) is an Additive Manufacturing technique, which allows production of highly complex solid metal parts with good mechanical properties, compared to conventionally manufactured parts. Nevert...Laser Powder Bed Fusion (LPBF) is an Additive Manufacturing technique, which allows production of highly complex solid metal parts with good mechanical properties, compared to conventionally manufactured parts. Nevertheless, the layer-by-layer fabrication process also offers several disadvantages, including a relatively high surface roughness depending on the shape of the component, its position and orientation during the fabrication process. This paper deals with investigations on the surface roughness reduction capability, and residual surface structures by laser polishing of LPBF AlSi10Mg parts under varying initial surface roughness in order to investigate the influence of the surface behavior and initial surface roughness to the achievable surface quality by laser polishing. Hereto test specimens with varying fabrication orientations regarding to the built platform are printed and further polished. Thereby the initial arithmetic roughness varies between 19.2 μm and 8.0 μm. It could be shown that the achievable surface roughness by laser polishing with continuous and pulsed laser radiation is increasing with rising initial roughness, but the relative roughness reduction is almost constant in the range of 95% - 97.5%. The analyzation of the residual roughness structures shows, that the main roughness differences is found in the middle and long structure wavelength regime, which are directly depending on the initial surface structures of 3D printing.展开更多
The main goal of this review is to give an overview of scientific publications concerning the employer attractiveness of German hospitals from the perspective of medical doctors in order to identify future research po...The main goal of this review is to give an overview of scientific publications concerning the employer attractiveness of German hospitals from the perspective of medical doctors in order to identify future research possibilities. After a summary of central problems concerning the German health sector and its current challenges, the study design behind the systematic content analysis as well as its criteria are presented. Selected results describe characteristics of expert literature for employer attractiveness in general, the attractiveness of German hospitals as employers (“hospital employer attractiveness” for short) as well as employer attractiveness from a medical doctor’s point of view. For each of these areas, focal points of research and main results are summarized and research gaps are pointed out.展开更多
文摘Laser Powder Bed Fusion (LPBF) is an Additive Manufacturing technique, which allows production of highly complex solid metal parts with good mechanical properties, compared to conventionally manufactured parts. Nevertheless, the layer-by-layer fabrication process also offers several disadvantages, including a relatively high surface roughness depending on the shape of the component, its position and orientation during the fabrication process. This paper deals with investigations on the surface roughness reduction capability, and residual surface structures by laser polishing of LPBF AlSi10Mg parts under varying initial surface roughness in order to investigate the influence of the surface behavior and initial surface roughness to the achievable surface quality by laser polishing. Hereto test specimens with varying fabrication orientations regarding to the built platform are printed and further polished. Thereby the initial arithmetic roughness varies between 19.2 μm and 8.0 μm. It could be shown that the achievable surface roughness by laser polishing with continuous and pulsed laser radiation is increasing with rising initial roughness, but the relative roughness reduction is almost constant in the range of 95% - 97.5%. The analyzation of the residual roughness structures shows, that the main roughness differences is found in the middle and long structure wavelength regime, which are directly depending on the initial surface structures of 3D printing.
文摘The main goal of this review is to give an overview of scientific publications concerning the employer attractiveness of German hospitals from the perspective of medical doctors in order to identify future research possibilities. After a summary of central problems concerning the German health sector and its current challenges, the study design behind the systematic content analysis as well as its criteria are presented. Selected results describe characteristics of expert literature for employer attractiveness in general, the attractiveness of German hospitals as employers (“hospital employer attractiveness” for short) as well as employer attractiveness from a medical doctor’s point of view. For each of these areas, focal points of research and main results are summarized and research gaps are pointed out.
