Research On Additive Manufacturing By Laser Cladding On Ductile Iron Roller

The laser cladding technology uses a high-energy laser beam as an energy input to generate a metal surface modification that satisfies the desired coating.The power,position and shape of the laser beam are easily controlled,and the choice of coating materials is flexible,which is of great significance in the surface repair of ductile iron rolls.This thesis focuses on the laser cladding on the surface of ductile iron,and explores difficulties in the process.The application of 304 steel,Ni25 alloy,F321 steel and Stellite6 alloy,as cladding material,is carried out.The macroscopic form,microstructure and microhardness of samples are studied.Cladding processing is optimized: powder thickness 1mm,power 1100 W,scan speed 100 mm/min.Ni25 alloy has the most comprehensive cladding effect and stable hardness transition,which can effectively alleviate the defects caused by cracking in the heat affected zone of the substrate.In addition,because it is difficult to obtain a track with controlled shape,compact structure,stable crack-free and good adhesion,this thesis,based on the level set method,the law of the conservation of momentum,mass and energy,builds an appearance molding simulation with the finite element method which is also tested by changing the simulation parameters.Through the comparison between test and experiment,the simulation stability of the model is accurate,and the shape and appearance of the cladding surface of the clad sample during the processing can be predicted and simulated.