Pulsed laser surface melting (pLSM) is a technique that offers an efficient and effective way to modify the geometry surfaces without any addition or removal of material. The resultant plays critical role in several applications. This paper presents steady-state thin-film approximation melt pool created by pLSM resulting semi-analytical solution for evolved geometry. These predictions are then ...

The relationships between the acoustic signal and the modes of the welding pool such as no-keyhole (melt-in), keyhole and cutting in variable polarity plasma arc welding (VPPAW) are investigated. Welch power spectral density (PSD) estimate is used for preprocessing the sound data. A neural network (NN) is used to distinguish the keyhole mode from the cutting mode. The results show that the keyh...

The parts manufactured by Additive Manufacturing (AM) techniques such as Directed Energy Deposition (DED) are generally quantified post-process inspection techniques. Though these reliable, they pose constraints in terms of cost and time. Additionally, the defective build states not known during actual processing. Real-time Artificial Intelligence (AI) based monitoring systems on rise an altern...

In this paper, a heat-flow coupling model of laser welding at preheating temperature was established by the FLUENT 19.0 software. The fluctuation keyhole wall and melt flow behavior in molten pool under different temperatures were analyzed, correlation between with spatters bubbles obtained. results indicate that when outer middle rear is convex, inner concave, which causes spatter or bottom to...

Acknowledgements I would like to dedicate this work to my caring, supportive, and devoted wife, Amy. I would also like to thank my parents and family for their continued encouragement throughout my education. In addition, I would like to thank Professors Uday Pal and Roger Kamm for their time, expertise, and guidance. Abstract Table of Symbols Chapter 1.0

Although lasers are widely used for welding in precision engineering industry, it is still a challenge to achieve high accuracy in creating and positioning welding spots at extremely high processing speed. Towards this end, we propose a system for monitoring the welding process in order to ensure good quality of the welding spots. Our technology enables high speed image acquisition confocally t...

The microstructural and mechanical properties of Laser Based Additive Manufacturing (LBAM) are still inconsistent and unreliable, which is a major barrier that prevents Additive Manufacturing (AM) from entering main stream production. The key challenge is the lack of understanding for the underlying process-properties relationship. We monitor Laser Engineered Net Shaped (LENS) process using a s...