The Experimental Research Of Fiber Laser Dressing Convex Arc Surface On Vitrified Bond Diamond Wheel

Vitrified bond diamond forming grinding wheels are widely used in grinding filed with excellent grinding performance.However,due to its high hardness and complex composition,there are problems such as low dressing efficiency and difficulty in profiling,which seriously hinders its promotion and application.Compared with other wheel dressing technology,laser dressing technology is a high-quality,high-efficiency,high-precision advanced dressing technology.In this paper,the nanosecond pulse fiber laser is used as the “dressing tool”,and the dressing and grinding test of the convex arc surface forming wheel was carried out,and the trimming effect of the pulsed fiber laser was evaluated by detecting the contour and surface quality of the grinding wheel and the ground graphite plate.(1)In this paper,a vitrified bond diamond convex arc surface forming grinding wheel dressing test platform based on nanosecond pulsed fiber laser was built,and the corresponding dressing scheme of the convex arc surface forming grinding wheel with a radius of 5 mm was designed,and the dressing track was designed according to the design.The numerical control G code program is programmed according to the dressing track.(2)The theoretical calculation and experimental verification of ablation threshold of fiber laser acting vitrified bond and diamond abrasive grain are carried out.The principle of fiber laser dressing convex arc surface forming grinding wheel is analyzed.The main process parameters of vitrified bonded diamond wheel dressing process are analyzed.Through analysis,5 variable parameters that have a large influence on the dressing quality of the grinding wheel are preferred.The influence of different process parameters on the profile and surface quality of the shaped grinding wheel after dressing was studied by a single variable method.The suitable process parameters were selected for the tangential profiling and radial sharpening of the vitrified-bonded diamond convex arc-shaped forming grinding wheel.After optimization,the tangential profiling parameters: average power is 40 W,grinding wheel speed is 500 r/min,scanning speed is 4.0 mm/min,repetition frequency is 100 kHz,defocusing amount is 0 mm;the radial sharpening parameters: average power is 20 W,grinding wheel speed is 500 r/min,Scanning speed is 4.0 mm/min,repetition frequency is 100 kHz,defocusing amount is +1 mm.(3)For the dressed grinding wheel,the super-depth microscope observation and extraction data were used to program the convex arc radius fitting and the contour radial runout analysis.The results show that the shape accuracy of the arc after dressing is high,but because the energy density of the spot is Gaussian,the grinding wheel is not a single material,and the effective radius of the laser will change during the dressing process,resulting in a certain error in the shape of the convex arc.In the profiling stage,the measurement and fitting convex arc radius and design radius error are within 60?m,the error is less than 1.2%,the contour radial runout range is 27.6?m,which meets the profiling requirements;in the sharpening stage,the required surface topography is obtained and the measured abrasive grain protrusion height of 85% meets the requirements,in line with the sharpening requirements.(4)Grinding detection test was carried out on the dressed convex arc surface forming grinding wheel.The super-depth microscope and CCD grinding projection method were used to observe the concave arc surface of the polished graphite plate,and the data was programmed to calculate the concave arc radius.Convergence contour radial runout analysis.The results show that: super depth of field detection,concave arc radius and design radius error within 40?m,error less than 0.8%,contour radial runout difference of 12.8?m,in line with the workpiece contour size design requirements;CCD grinding projection detection,concave arc radius and design radius error within 20?m,error less than 0.5%,contour radial runout range of 12.2?m,in line with the workpiece contour size design requirements;further reflecting the dimensional accuracy of the contour of the convex arc after grinding,and also meets the finishing requirements.