Analytical method to study the temperature distribution of a moving heat source electron beam micro-welding

Abstract

Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.Recently, the use of electron beam for micro-welding has become one of the primary research areas. Electron beam can behave as a volumetric heat source and is capable of traveling very fast and focusing at very small spot sizes. This proves ideal for welding at small scales as thermal stresses and losses due to ablation are controlled in the material. The choice of beam parameters remains a challenge as it depends on many factors like characteristics of the material and nature of application. An understanding of the beam-substrate interactions and hence the temperature distribution in the material due to this, can lead to wide spread applications of this technique. An analytical method based on the theory of heat transfer is proposed in the present work to yield the temperature distributions in the material during electron beam micro-welding. Plots identifying the maximum temperature and region of melting, obtained as results of the study, can help to optimize beam parameters for a process. The material properties of stainless steel are used to plot the temperature distribution in the material during micro-welding. The formulation is also extended to make use of electron beam for nano-welding, extrapolating the macro-level properties. For the case of nano-welding, the weld characteristics like the maximum temperature, weld depth and width are obtained for the specified values of the beam parameters, using the material properties of silicon.