Real-time Sensing and Control of Metal Powder Laser Forming

Metal powder laser forming (MPLF) is a promising manufacturing technology that can be widely applied to part reparation, surface modification and solid freeform fabrication (SFF). A large number of parameters govern the MPLF process. These parameters are sensitive to the environmental variations, and also influence each other. The present research work on improving the performance of the MPLF process is introduced. A closed-loop control system based on industrial CCD camera and infrared photodetector was built to control the heat history and the size of the molten pool in MPLF process. A real-time sensing and control system on the forming height was devised. An industrial CCD camera and a line-structure laser were used to monitor the height, and the delivery rate of the metal powder was on-line controlled. An optoelectronic sensor was developed to sense the metal powder delivery rate in real-time. The closed-loop control results show a great improvement in the geometrical accuracy of the built features. The stabilization of the MPLF process changes better