Study On Equipment And Technics Of Laser Microcladding By Pulsed Feeding Powder

Laser cladding has important application prospects in industrial applications and scientific research. In which, the design of new powder feeders is the most important part of cladding equipment development. A pulsed powder feeder and its control system with small mass powder(milligramme level) and pulsed feeding ability were researched, which can meet the needs of repairing the workpieces with small dimension defects.In this paper, the working principle of the pulsed powder feeder, the principle of circuit design and implement of software to control pulsed powder feeder are discussed. In the circuit design work, the entire system is devided into three modules: pulse control unit, keyboard input unit and digital display unit. In the software implement part, the working of the pulsed powder feeder is controlled by calling the subroutine in turn.Powder feeding tests of the new pulsed powder feeder were conducted. The effects of working time and travel distance on the stability and shape of fed power were discussed. Laser micro-cladding of nickel powder were carried out on the rustless steel sheet by using pulsed YAG laser. Moreover, the effects of laser power, pulse width and scanning speed on the performance of cladding layer were discussed, respectively.The results show that powder feeding stability is very high and good shape of fed powder is gotten for the designed pulsed powder feeder. Especially, this powder feeder can realize pulsed and small mass powder feeding(milligramme level). Comparatively, the minimum diameter of the cladding layer is about 189μm during point laser cladding, but the minimum line width of the cladding layer is about 154μm during linear laser cladding. Cladding layers with good shape, low dilution rate and high hardness can be gotten by optimizing laser cladding parameters.