Spatial intensity profiling of an industrial laser welding system

A investigation was conducted to devise a method to sense the laser beam intensity profile of an industrial laser welding system. The research focuses on monitoring methods and assessing locations within the system where data can be taken which reveal the relationship between the laser beam intensity profile and the input system parameters of the laser beam welding process. Emphasis has been placed on the configuration of a distributed computing environment to acquire, analyze and display the results of the sensed beam profile. Conventional image processing techniques are demonstrated. It was found that a distributed computing environment was useful for processing the large volumes of data generated by this process characterization method, and the distributed computing environment provided the computing power required for computationally intensive analysis and display techniques. The mathematical techniques used to discriminate one data set from another and relate the results to processing conditions are discussed

Modeling of laser energy concentration in narrow gap joints

A three-dimensional, computer based, optical ray tracing model is used to simulate the combined effect of key geometric parameters for laser welding. This allows one to characterize a range of joint designs for their ability to concentrate or dissipate laser energy. The effects of angle dependent absorption and diffuse reflections on beam transport are evaluated through simulation to determine the contributions of these effects on the system. The effects of energy loss through weld joint gaps are modeled for common weld joint preparations. Practical applications of extending the optical design of the system to include the weld joint are proposed

Ultra-narrow gap laser welding of BeAl alloys. Final report

The original scope of the project was to develop a method to enhance the laser welding of BeAl alloys by the use of weld joint designs based on the principals of non-imaging optics. The projected three year program focused on the development of geometric optical models which predict the trapping of laser energy within the weld joint and experimental validation of these models. The first year was fully funded, meeting all expectations and deliverables for the demonstration of the method for aluminum only. The second year funding levels did not allow any work to be done at Los Alamos. OptiCAD continued with model development with a change in scope to model the laser welding requirements of ongoing weapons related programs which could provide data for model validation. The project ended at the end of FY97 without funding a third year and never reaching the goal of welding beryllium, as a result. Despite the poor funding situation, original quality process research was accomplished and reported as described in the three technical reports of Appendix A. Solid technical contribution, directly applicable to weapons programs is evidenced by the inclusion of an optically designed laser weld joint being specified on a LANL drawing of an aluminum subassembly