Product Code: ICA13_1701

Dynamic Observation of Formation Process in Laser Cladding Using High Speed Video Camera
Authors:
Nobuyuki Abe, Joining and Welding Research Institute, Osaka University; Ibaraki Japan
Masahiro Tsukamoto, Joining and Welding Research Institute, Osaka University; Ibaraki Japan
Yoshihiko Hayashi, Joining and Welding Research Institute, Osaka University; Ibaraki Japan
Hiroyuki Yamazaki, Joining and Welding Research Institute, Osaka University; Ibaraki Japan
Daichi Tanigawa, Osaka Univ.; Yamada,Osaka Japan
Yoshihiro Tatsumi, Osaka Fuji Corporation; Amagasaki Japan
Mikio Yoneyama, Osaka Fuji Corporation; Amagasaki Japan
Presented at ICALEO 2013

Laser cladding is one of the useful methods for improving the quality of wear and corrosion resistance of material surfaces. Compared with other methods, for example plasma transferred arc welding, thermal spray and so on, advantages of laser cladding are small heat affected zone, low heat distortion of substrate and high adhesion strength to substrate. Moreover, formation of smooth cladding layer and high deposition rate are required from the stand point of production. Reduction of penetration to substrate is also important for cladding layers.
In this study, the fundamental process of laser cladding was revealed in order to achieve both smooth cladding layer and high deposition rate. The effect of the cladding parameters such as laser power, overlap rate, scanning speed and laser beam profile were investigated on formation process of cladding layer. Powder material was pre-placed on the substrate. Elliptical diode laser beam was scanned along its short axis with overlap. The surfaces and the cross sections of cladding layers were observed by optical microscope. Formation phenomena of cladding layers were observed with high speed video camera to analyze the cladding layer formation process.
The cladding layer with smooth and low penetration to substrate was formed at a combination area of the cladding parameters such as heat input per unit length and overlap rate at a constant beam profile. The analysis of high speed images revealed that the molten pool became wider with increasing overlap rate. This wider molten pool remelted the lough surface and made cladding layer surface smooth.