Thermal Behavior and Microstructural Evolution during Laser Deposition with Laser-Engineered Net Shaping: Part I. Numerical Calculations

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 39; no. 9; pp. 2228 - 2236
• Main Authors: Zheng, B., Zhou, Y., Smugeresky, J.E., Schoenung, J.M., Lavernia, E.J.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.09.2008; Springer; Springer Nature B.V
• Subjects: Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Exact sciences and technology; Materials Science; Metallic Materials; Metallurgy; Metals. Metallurgy; Microstructure; Nanotechnology; Production techniques; Residual stress; Solidification; Spray forming; Structural Materials; Surface treatment; Surfaces and Interfaces; Temperature; Thin Films; Travel Speed; Molten Pool; Apparent Heat Capacity; Thermal History; Finite Difference Method; Calculation; Microstructure; Laser deposition; Laser
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-008-9557-7

Laser-engineered net shaping (LENS) is a rapid direct manufacturing process. The LENS process can be analyzed as a sequence of discrete events, given that it is a layer-by-layer process. The thermal history associated with the LENS process involves numerous reheating cycles. In this article, the thermal behavior during laser deposition with LENS is simulated numerically by using the alternate-direction explicit (ADE) finite difference method (FDM). The simulation results showed that deposited material experiences a significant rapid quenching effect during the initial stages of deposition and can attain a very high cooling rate. With an increase in deposit thickness, the rapid quenching effect decreases and eventually disappears. The effects of the processing parameters on the thermal behavior of deposited materials were also simulated and analyzed. The objective of this study is to provide insight into the thermal history during the LENS process, where the ability to correlate process parameters to microstructural evolution is a motivating force.