Study On The Morphology Of Laser Cladding Layer On Inclined Substrate

Laser cladding is an advanced surface modification and surface repair technology,whichhas been widely used in aerospace,automotive,equipment manufacturing and other fields.At present,many researches are based on the horizontal substrate,and the laser head is perpendicular to the substrate,but in the actual production process,most parts are complex,the laser head may interfere with the part.This paper provides a solution for laser cladding of inclined substrate.By inclining the surface to be repaired to avoid collision between the laser head and parts.However,the relevant research is less,the theoretical basis is not perfect.In this paper,the basic experimental research on laser cladding of inclined substrate is carried out:Firstly,the molten pool depth of laser cladding layer was studied.Based on Mie scattering theory,the theoretical model of the energy distribution on the substrate surface during laser cladding is established,and the model is verified by experiments.The depth of the weld pool is proportional to the peak value of the energy density,and the offset of the weld pool is the same as that of the energy density.Secondly,the shape of the cladding layer on the laser cladding layer was studied.The combination of two ellipses is used to represent the shape of the cladding layer on the inclined substrate.The relationship between the inclined angle of the substrate and the shape of the cladding layer(the width,the height,the area and the offset of the cladding layer)is studied.Then,the influence of laser parameters,such as laser power,powder feeding rate and scanning speed,on the depth and offset of the weld pool was studied when the laser cladding was carried out on 50 degree inclined substrate.The relationship between the morphology and quality of the cladding layer and the processing parameters on the 50 degree inclined substrate was also studied.Next,the morphology of the multichannel cladding layer on the inclined substrate was studied.The morphology and surface quality of the cladding layer were observed by four scanning methods on the inclined substrate.The four scanning modes were along the y axis direction,along the negative direction of the y axis,along the x axis direction and on the horizontal substrate.The choice of scanning direction is put forward.Based on the above research,the characteristics of the four scanning methods are studied.The four scanning mode is along the x axis scanning from the bottom up,along the x axis scanning from top to bottom,along the y axis forward scan and negative scan along the y axis,which laid the foundation for the actual repair.Lastly,repair a part by laser cladding.The size and surface quality of the cladding layer meet the requirements.However,the surface adjacent and opposite to the surface to be repaired will produce a burn mark due to the reflection of the laser.The powder can be bonded to the adjacent and opposite surfaces,which has an effect on the surface quality and properties.Therefore,the protection of other surface should be taken in laser cladding repair.It is proved by theory and experiment that it is feasible to repair the parts by laser cladding on inclined substrate.