A new method for improving the forming quality in laser additive manufacturing process

Abstract

The melt pool temperature plays a very important role in the laser additive manufacturing (LAM) process which has been widely used in different industries. In this process, simple laser scan strategies and constant laser power levels are usually used, which will elicit variations in the melt pool temperature and ultimately affect the forming quality such as the cracks and pores. In this paper, a new method for improving the forming quality was presented, which calculates the local thermal distribution dynamically by analyzing the laser scanning path included in a G-code file. A factor called the thermal distribution factor (TDF) was used to adjust the laser power. By inserting the adjusted laser power into a modified G-code file, the melt pool temperature can be controlled indirectly. This method can help to control the melt pool temperature and improve the forming quality at the lowest cost. An experimental set-up was designed to verify this method and the results were analyzed. Results indicated that the cracks and pores of the part were significantly reduced by using the modified G-code file. Besides, the drawbacks and the future potential improvements of this method were discussed.