Research On Laser Cladding Technology Of Prefabricated Welding Wire

Laser cladding,as a kind of surface strengthening technology,is widely used in laser surface cladding,laser cladding repair and remanufacturing,laser rapid prototyping and other fields.In recent years,however,for the preset welding wire method is adopted to complete the laser cladding processing research is not thorough,therefore,the research of laser compound forming process parameters on the preset welding wire morphology,size and the influence law of forming quality,further enrich the shape control theory of laser cladding technology on laser cladding technology application in the actual production and life of great significance.In order to study the influence of laser cladding process parameters of prefabricated welding wire on part forming,experiments of single-point weld with different process parameters,single-track weld with different process parameters,multi-track cladding layer with different welding trajectory and weld lap spacing and prefabricated welding wire laser cladding forming of cuboid parts were carried out in this paper.The section morphology and size of single-point weld,the surface morphology and section morphology of single-track weld and the surface quality of multi-track cladding layer were analyzed.The influence of process parameters on the forming of laser cladding layer was studied,and the forming ability of parts of laser cladding process method of prefabricated welding wire was verified.The main research results of this paper are as follows:The power density distribution in laser spot affects the shape and size of single spot weld.With the increase of laser power,the shape of single-point weld formed by non-oscillating Gaussian beam gradually changes from parabola to bell shape,and the weld width,weld depth,depth to width ratio and weld width ratio of single-point weld increase accordingly.With the increase of swing range,the shape of single-point weld gradually changes from bell shape to bowl shape,and the fusion depth and depth ratio of single-point weld gradually decrease while the fusion width ratio gradually increases.With the increase of welding time,the weld depth and weld width of singlepoint weld gradually increase,but the ratio of depth to width remains unchanged.The energy density of fiber laser affects the size and surface quality of single-track weld.The laser energy density increases with the increase of laser power,and the weld surface width,weld depth and effective weld width gradually increase.However,if the energy density is too large,the welding depth of single-track weld is too large and the surface morphology is poor.The change of swing amplitude can change the average laser energy density.With the increase of swing amplitude,the weld depth decreases and the weld surface width increases slowly,but the swing amplitude is too large to lead to the poor surface topography of the single-track weld.The change of welding speed has a great influence on the weld size.With the increase of welding speed,the surface weld width and effective weld width decrease,and the weld depth decreases slowly.If the welding speed is too small,the surface morphology of single-track weld will deteriorate.When the welding path is perpendicular to the preset direction of the welding wire,the surface roughness of the multi-track cladding layer is small.For certain process parameters,a suitable lap spacing can obtain better forming quality of cladding layer.If the weld lap spacing is too small,the energy density will be too large,which will lead to the gasification of elements in the cladding layer and the increase of surface roughness and deformation.Too large weld lap spacing results in non-fusion and large surface roughness.The prefabricated welding wire laser cladding of cuboid parts was realized by using the optimized process parameters.