The invention discloses an online detecting and eliminating device and method for melt channel material defects in
laser metal forming. The device and method are suitable for a
laser metal deposition forming process. The device comprises four
optical fiber type double-
color temperature gauges, and four temperature measuring probes of the
optical fiber type double-
color temperature gauges are fixed to the left side, the right side, the front side and the back side of a coaxial
powder feeding
nozzle of a forming
system correspondingly; detection aiming points of the four temperature measuring probes are aligned with the left side, the right side, the front side and the back side of a forming scanning
laser spot on a forming plane correspondingly, the detection aiming points are away from the center of the laser spot by a certain micro-distance, and the four temperature measuring probes, the coaxial
powder feeding
nozzle and a laser beam move together; during forming, when the coaxial
powder feeding
nozzle and the laser beam conduct forming scanning in any one of the -X direction, the X direction, the -Y direction and the Y direction, the temperature measuring probe located at the side opposite to the scanning direction of the coaxial powder feeding nozzle is used for detecting the temperature of the position, away from the laser spot by a certain micro-distance, of a high-temperature melt channel, and when the temperature mutates abnormally, it is judged that the material defects exist in the position, the defect positions are determined, and laser targeted remelting is carried out on the defects.