Additive Manufacturing of Metals via Selective Laser Melting Process Aspects and Material Developments

This chapter provides a basic insight into the selective laser melting (SLM) process. It reports the state of the art in SLM of metals and describes the latest developments enabled by the efforts of researchers at the University of Leuven (KU Leuven). After an introduction, the SLM machine components (including the basic units and process layout) as well as hardware additions (such as a preheating stage and monitoring systems) are explained. The melting/solidification conditions and the corresponding quality issues are briefly reviewed as well. Important SLM parameters and additional considerations such as geometrical aspects or laser remelting/erosion abilities are described. After this, a survey of various SLM materials, including a number of steels, aluminum alloys, and titanium alloys, in addition to functional and advanced materials such as refractory tantalum and shape-memory NiTi, is given. The microstructural and mechanical properties of SLM materials are discussed and compared with those produced by conventional methods. Possible methods to mitigate SLM problems such as cracking and residual stresses are also suggested. Finally, this chapter explains different post-processing treatments and illustrates that conventional post-processing techniques might not be efficient or suitable for some SLM materials.status: publishe