Product Code: ICAL06_208

Crack Behavior and Characteristics of Laser Clad Layer with Powder Mixture of Co-Based Alloy and WC
Authors:
Guojian Xu, Nagoya University (Present: LASER X CO. LTD. Chiryu, Japan); Nagoya Japan
Liquan SUN, Chang Chun Institute of Technology; Chang Chun Peoples Republic of China
Muneharu KUTSUNA, Graduate School of Engineering, Nagoya University; Nagoya Japan
Zhongjie Liu, Nagoya University; Nagoya Japan
Presented at ICALEO 2006

The powder mixture of Co-based alloy (Stellite-6) and tungsten carbide (WC) in the range of 0wt% ~ 47wt%WC were deposited on mild steel (JIS-SM400B) plates by a 2.4kW cw CO2 laser. The influence of a preheating temperature, WC weight fraction, cladding methods on the crack sensitivity of clad layer was examined. To decrease the crack sensitivity of clad layer, a normal multi-layer cladding and a novel multi-layer cladding were comparatively investigated in the experiments. As the result, the crack sensitivity of clad layer using novel multi-layer cladding is lower than that of normal multi-layer cladding. On the other hand, the phase constitution, crack form, microstructure, hardness and wear resistance of the clad layer were investigated by an X-ray diffractometer, energy dispersion spectroscopy (EDS), scanning electron microscope (SEM), laser microscope, Vickers hardness tester and wear tester. According to the analysis results, the cracks of clad layer with the powder mixture of Stellite-6 and WC belonged to a quasi-cleavage fracture type crack. The microstructures of clad layer consist of hypoeutectic structure and unmelted WC. The Vickers hardness of clad layer increases with the increase of WC weight fraction. The clad layers of normal multi-layer cladding and novel multi-layer cladding have almost same wear resistance.