Disk-shaped Cam Surface Laser Cladding

Theoretical and experimental researchs about the process of laser cladding on the disc cam have been studied in this paper. The key issue in this process by which can get uniform laser cladding layer is that it should keep the heateffect equal all the time during the laser cladding. There are many methods to resolve this problem, such as changing the power, or the scanning velocity. Another method is by the moving control to obtain the goal.In order to attain the purpose,the author analysises the equipment the lab possesses,and at last decides to use the method of moving control.Therefore the problem about the moving control of the laser cladding on the surface of the disc cam continually now becomes the main idea of this article.The difficulty of the issue on the moving control increases as the contour line is complex curve.There are three conditions should be satisfied when we want to get the circular and uniform laser layer on the surface of the disc cam,these conditions as follow:First,the laser beam should incidence along the normal of the surface of the disc cam; Second,the defocus capacity also should be kept not changeable; Third, the scanning velocity of the laser spot is supposed to keep invariablenes.This paper puts forward the theory which scatters the contour line of disc cam into equivalent circular arcs lines or straight lines,and adopts moving of the x,z,Wof the NC-machine simultaneously to resolve the moving control of the laser cladding on the surface of disc cam. It is validated to be feasible by analyzing the macrostructure and microstructure of the different section planes on the laser cladding layer.A lot of numeration and logic verdict in the programming of NC-machine have been finished by the digital and analysis software MATLAB. At the same time a NC-machine programme editor module about moving control of the laser cladding on the disc cam has been developed. As to the width of the contour surface is wider than the laser spot, it should use the scanning process of laser overlapping cladding.In this situation,it will encounter the problem of the cladding layer flatess and.And the uniform issue of cladding layer along the direction of the shaft. In the article the author gets the perfect coefficient of the laser cladding overlapping layer, then the uniform cladding layer along the axis is obtained by symmetric scanning.laser cladding crack is the main issue in the laser cladding technology.also it is one of the problems of the laser cladding on disc cam.The factors of laser cladding layer crack are many.such as choosing the cladding powder, and the condition pretreatment of the substrate.Second, the dimension of the laser spot, the defocus capacity.the power of laser beam,the scanning velocity v_s ,and the capacity of powder feeding v_f,and so on.Except for these factors,the figure of the substrate is also one reason. Accordding to the analysis, the author chooses the low melting point powder to be used in the experiments, and does many researchs.at last finds out the reasonably matching process coefficient which can prevent the crack appearing on the cladding layer.The collapsar on the brim of disc cam in the laser cladding is inevasible,when the laser beam which has high energy irradiates on the edge of the cam's surface.the powder and the substrate melt simultaneously.their liquid will flow off one side of the disc cam, and then the collapsar is formed.In order to avoid the collapsar the author adopts the process that it clads the sides of the cam earlierly,secondly dads the contour surface of the cam,or the scanning order is opposable,also uses the added material process,but at last chooses the first method through analysis and comparation.