Research Initiation: Solid-Liquid Interface Morphology During Welding

点击翻译按钮获取中文摘要

The goals of this research are to understand the reasons for the appearance of different solid-liquid interface morphologies during the autogenous full penetration welding of single and polycrystalline thin plates. The research will identify the role that heat flow, surface tension, interfacial kinetic effects and grain boundaries play (which include the effects of crystallographic anisotropy) in the development of the weld pool shape and the resultant properties of the fusion zone. Methods of research include numerical calculation of solid-liquid weld pool interfaces modeled as nonlinear free or moving boundaries, that account for heat flow and are coupled with the interfacial properties, by using finite difference, finite element, spectral and/or boundary integral techniques. Furthermore, numerical calculation of sharp transitions in classes of weld pool shapes using analytical (both linear and nonlinear) asymptotic analysis will be performed whenever applicable; the analysis will be helpful in gaining a clearer knowledge of special limiting cases and for comparison with the numerical results. The results will be compared to existing experimental results, and the goal is to ultimately provide a correlation between a set of welding conditions and final material properties. This would provide an understanding of the types of welding methods that might eliminate or circumvent deleterious weld pools shape features which give rise to sites for defect generation and textured fusion zones. The project has potential to improve the quality and control of the welding process.