Towards High Build Rates: Combining Different Layer Thickness within One Part in Selective Laser Melting

Additive manufacturing of metallic parts using powder bed based fusion processes like selective laser melting is increasingly used in industrial applications. With typical layer thicknesses of 20 – 40 µm good surface qualities and high geometrical accuracy can be achieved compared to other AM processes. However, low layer thicknesses are to the detriment of build rates as more layers are required. Increasing the layer thickness can significantly increase build rates at the cost of surface quality and accuracy. In this paper a new parameter set for a layer thickness of 60 µm is developed and combinations of different layer thicknesses within one part are investigated. Thus increased build rates can be achieved while a high accuracy can be maintained when locally required. Specimens with combination of different layer thicknesses in various build orientations are produced and mechanically tested. Micrographs of the layer transitions are examined and recommendations for their design are given.