Light Weight Materials

6FEA Comparative Studies on Heat Flux and Thermal Stress Analysis during Conduction Mode and Keyhole Mode in the Laser Beam Welding

Laser welding is one of the key weld processes used for joining metals in which high joint strength is obtained with low heat-affected zone. This chapter presents suitable models used for the application of a Gaussian beam profile and the frustum model to conduction mode welding and keyhole laser welds. Temperature and stress analysis were carried out within and around the weld region. This chapter discusses the analytical comparative approximation of different model approaches applicable to the laser weld process. The parametric study and analysis can effectively be used in order to design and optimize the weld process parameters for engineers widely employed in the manufacturing sector like nuclear, aeronautical and chemical plants.

6.1. Introduction

Laser welding is one of the advanced joining processes used for steels in various applications such as nuclear reactors, chemical pipelines, automobile and aeronautical sectors. The advantages of low heat input, high-speed production rates and narrow heat-affected zone formation are considered for typical applications. For fabrication, thin sections are joined using low power lasers (conduction mode), while thick sections are joined using high power lasers (keyhole mode) (Nath et al. 2002). In the conduction mode welding process, which employs low laser input power (<1 kW and lower heat input), weld ...