An Experimental Study Of Dressing Electroplated Diamond Wheels With Pulsed Ultraviolet Laser

Electroplated diamond grinding wheel is widely used in the processing of hard and brittle materials because of its excellent grinding performance.Due to some electroplating process,the surface of the grinding wheel is easy to produce nickel bumps which affect the grinding performance.The traditional mechanical dressing method is of poor effect and low efficiency.As a new type of grinding wheel dressing tool,laser dressing is studied by few scholars in the field of electroplated diamond grinding wheel.In view of the above situation,a set of test platform is designed and set up to dress nickel-bonded electroplated diamond grinding wheel with a pulsed ultraviolet laser in this thesis.A series of experiments are carried out on the dressing of electroplated diamond grinding wheels.The detail description is listed as follows:(1)The influence of the laser spots' center distance on the ratio of the spot coverage is theoretically analyzed.The effect of overlap ratio and scanning filling methods on the topography of nickel-bonded electroplated diamond grinding wheels is experimentally researched.The results show that it is necessary to ensure the 100%ratio of the spot coverage so that the ablation pits can be completely covered in the ablation zone,that is to say,the laser spots' center distance should be selected in the 0-24.75microns.With the increase of the laser spot overlap rate and the track line overlap ratio,the surface of the dressing wheels tend to be flattened.When they are 35%,the topography of dressed diamond wheels is suitable.In addition,the topography of dressed diamond wheels is appropriate under the condition of circle fill.(2)The ablation threshold of pulsed ultraviolet laser processing diamond is obtained from the angles of theoretical calculation and experimental measurement.The influence of average laser power and numbers of scanning cycles on the ablation depth of nickel-bonded electroplated diamond grinding wheels is studied.The results show that when average laser power is greater than 4.5W and remains unchanged,the ablation depth of electroplating diamond wheel is in proportional to numbers of scanning cycles.When average laser power is lower than 4.5W and remains unchanged,the ablation depth of electroplating diamond wheel rises slowly with the increase of numbers of scanning cycles.(3)The influence of feed rate and moving speed of the CNC engraving and milling machine's spindle on the Gorilla Glass 3 is experimentally researched.A comparative study of grinding test by the undressed and dressed electroplated grinding wheel is carried out.The results show that it will be helpful to reduce the maximum cutting thickness of the single abrasive grain to select properly smaller feed rate and moving speed of the spindle,thereby reducing the crack of the edge of glass cover.Compared with the undressed grinding wheel,the grinding effect of glass cover by the dressed grinding wheel is better,which can meet the quality requirements of the product.