Investigation On Laser Cladding Hard Alloy And Laser Cladding Hard Alloy With Electromagnetic Stirring

In the processing of laser cladding for hard alloy , the difference of density and character of compositions lead to component segregation, and the cracks in the laser cladding coating are mainly related to the component segregation. Electromagnetic stirring has been used in laser cladding processing in this paper. A electromagnetic stirring equipment for laser cladding has been designed and made, its output is plane rotate magnetic field, its magnetic field strength linearly increases with the increase of input current. The distribution of magnetic strength in the same altitude plane are basically the same, the strength in the center is little higher than that of the edge, when the input current is 20A, the magnetic field strength in the center reach to 75 mT. Investigation has been carried out into the laser cladding of hard alloy.It shows that the flowability of the molten bath improves and the emerging of gas hole in cladding coating can be eliminated when Al material with low melting point is added and that the wettability of TiC obviously improves and the claddability of hard alloy coating increases when Ni material is added. Investigation on laser cladding hard alloy with electromagnetic stirring has been done. The results show that electromagnetic stirring can affect on the micro-structure of the coating. It can refine the WC structure and make them homogeneous, and it can also refine the branch crystal in transition region of the coating.Otherwise,the electromagnetic stirring technology have some effects on the resistance for crack and gas hole in laser cladding,it can enhance the quality of laser cladding.