A Review on Direct Metal Laser Sintering: Process Features and Microstructure Modeling

Abstract

Additive manufacturing (AM) has gained market interest in recent times, due to improvement in technologies and introduction of new metal powders for the end product with the application on different fields such as aerospace, medical and automotive sectors. Laser-based additive manufacturing is presently regarded as the most versatile process in additive manufacturing. This manufacturing technology produces three-dimensional complex shapes from the powder material in a layer by layer fashion directly from the metal powder. The process has the potential to be more flexible, to produce a wider range of shapes, and to form more challenging materials. As it is a rapid manufacturing technique, in which complex non-equilibrium physical and chemical metallurgical phenomena takes place. These phenomena will directly affect the qualities of build parts, which are dependent on the microstructure as well as process parameters. Thus, to understand the processing mechanism and the prediction of part microstructures during the process may be an important factor for process optimization. At the present time, an increase in computational resources allows for direct simulations of microstructures during materials processing for specific manufacturing conditions. So, there is a demand to develop an integrated computational platform coupling various phenomena or models together to understand and ultimately control and optimize the AM build process. The objective of this review is to present a thorough analysis of direct metal laser sintering process, process parameters, sintering mechanism, and comprehensive discussion on the phase field method for microstructure evolution and its application. This review aims at providing an insight into the mechanism of the processes and microstructure evolution both experimentally and numerically. It will act as a guide for researchers working on additive manufacturing and would also provide the future research gap for further studies.