A Brief Study On Fabricating Cutter Blade By Laser Cladding With Electromagnetic Stirring

Cutter blade is widely used in industry of chemical fibre and consumed numbers, it required high level of properties such as hardness, abrasive resistance and impact toughness. The processes of existing methods for making blade are complex and cost more. Laser cladding is one of the surface treatment technologies that can obtain high performance layer on the common substrate. Electromagnetic Stirring(EMS) is one of semi-solid forming technologies that can reduce flaws in the process of liquid metal solidification and enhance the characters of solidifying structure. Laser cladding has been used as a method to making blade, and EMS also has been utilized to improve the laser cladding layer. It will reduce the cost of making blade.To meet the ascertained requirement of blade, The formula of laser cladding powder has been designed. It consists of WC-Co carbide hard alloy mainly and suitable quantity of Al and TiC powder. The experiment of making blade through laser cladding has been carried out. and the effect results to the structure and hardness of laser cladding layer by various ingredients have been illustrated. It has been done to investigate the reasons lead to porosity and crack of the layer by laser cladding Cemented Carbide, some restrain measures have been given.Comparing effective results to the quality of these layers under different EMS level which was generated by an existed Electromagnetic Stirrer has been done, the Stirrer's maximum output horizontal magnetic field is 75mT. The results showed that EMS have some effects on the resistance for porosity and crack in laser cladding, and it also can refine the WC microstructure and make them homogeneous, enhance the cladding layer characters such as hardness and dynamic strength. For the WC-Co powder formula, the stronger of the input EMS strength below 75mT level is, the higher quality of the laser cladding layer is.The schematic diagram of controlling solidification microstructure of laser cladding layer under EMS has been set up. A ideal laser cladding free from porosity and crack has been attained by adjusting and optimizing cladding process parameters according with the rule of the schematic diagram, its average hardness reached HV0.21350, it can fulfil the requirement of blade.