CRITICAL REVIEW ON CHRACTERIZATION OF DMLS MATERIALS

Direct Metal Laser Sintering (DMLS) is an Additive Manufacturing (AM) technique in which the metal powder will be sintered in selected regions as per 3D CAD file in a layer by layer fashion in an inert atmosphere to produce part of any geometrical complexity with ease. Approximately 150 published works were examined. In this paper most widely used DMLS metal powders mechanical and tribological properties were analyzed and the effect of post processes on the material properties were discussed. The objective of the paper is to consolidate the works done so far and to identify apertures to extend scope of this technology. The emerging and out reaching application of this revolutionary technology in various sectors like biomedical, aerospace and automotive was also discussed based on material properties. This review would help researchers to find challenges in this booming technology. As per the materials point of view future research prospective was suggested in depth in light of present review. Keywords, DMLS, Additive Manufacturing, Metal powders, Mechanical properties, Tribological properties. 1.0 Introduction At present, additive manufacturing (AM) is an invigorated technology in sectors like bio medical, dentistry, aerospace, automobile and manufacturing [1]. In this technique, there is an addition of material in a stacking manner to build a prototype or a functional part despite of subtracting material from stock as in the case of conventional machining. Beside of having limited availability of feasible materials and machines, it is emerging technology capable of producing small and medium lot size parts in relatively less time with more accuracy. There is availability of more work space and flexibility of manufacturing due to no tooling. According to ASTM, the AM technologies are of two types namely Powder Bed Fusion (PBF) and Direct Energy Deposition (DED). The further classification was shown in Fig. 1[2]. In the present paper we emphasized only on Direct Metal Laser Sintering (DMLS) is one of the techniques of PBF. In DMLS metal powders are used to build a 3D object directly from a 3D CAD file. Basically, the final object can be obtained in the machine on a moveable platform by applying powder material as successive layers [3-7]. Journal of Xi'an University of Architecture & Technology Volume XII, Issue IV, 2020 Issn No : 1006-7930