A study of process parameters on workpiece anisotropy in the laser engineered net shaping (LENSTM) process. (15th May 2017)

• Record Type: Journal Article
• Authors: Chandra, Shubham; Rao, Balkrishna C
• Is Part Of: Journal of physics. Volume 50:Number 22(2017)
• Publication Date: 2017-05-15
• Subjects: LENSTM -- anisotropy -- additive manufacturing -- superalloy; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/aa6d3b
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: The process of laser engineered net shaping (LENS TM ) is an additive manufacturing technique that employs the coaxial flow of metallic powders with a high-power laser to form a melt pool and the subsequent deposition of the specimen on a substrate. Although research done over the past decade on the LENS TM processing of alloys of steel, titanium, nickel and other metallic materials typically reports superior mechanical properties in as-deposited specimens, when compared to the bulk material, there is anisotropy in the mechanical properties of the melt deposit. The current study involves the development of a numerical model of the LENS TM process, using the principles of computational fluid dynamics (CFD), and the subsequent prediction of the volume fraction of equiaxed grains to predict process parameters required for the deposition of workpieces with isotropy in their properties. The numerical simulation is carried out on ANSYS-Fluent, whose data on thermal gradient are used to determine the volume fraction of the equiaxed grains present in the deposited specimen. This study has been validated against earlier efforts on the experimental studies of LENS TM for alloys of nickel. Besides being applicable to the wider family of metals and alloys, the results of this study will also facilitate effective process design to improve both product quality and productivity.