Study On Fiber Laser Dressing Of Resin-bonded Diamond Wheel And Its Grinding Performance

Because of its high hardness and good wear resistance,super-hard abrasive wheel has excellent grinding performance.But due to these characteristics,there are various problems in the dressing process.Compared with the traditional dressing method,the laser dressing method of grinding wheel is a very advanced technology,with high efficiency,low cost,no pollution,wide applicability and great potential.However,the current research on laser dressing super-hard grinding wheel is not thorough enough,which limits the application of laser technology in industrial application,it can only be carried out in the laboratory,as the auxiliary application of mechanical dressing methods.Firstly,due to the limitation of lasers equipment,most correlation studies are not in-depth enough and innovative methods cannot be proposed to solve the problem of insufficient accuracy.Secondly,there is a lack of systematic evaluation of the effect of grinding wheel dressed by laser,so it's urgent to develop a standard to promote the technology of laser dressing.In this paper,the diamond grinding wheel was dressed by a pulsed fiber laser.The effect of diamond wheel,dressed by laser,was evaluated with observing the surface topography and analyzing the grinding performance.First,a laser dressing and grinding test platform for resin diamond grinding wheel was established,which consisted of pulsed fiber laser,optical path transmission device,CNC high precision surface grinder,mechanical dressing device,etc.Then,a series of experiments was carried out,in which the diamond wheel was tangential shaped,with selecting appropriate laser parameters.Then the topography were observed after dressing.It was found that the grinding wheel had high profile accuracy,and the surface of the bond was relatively flat,although there were a little pits.After shaping,the experiment of radial sharpening resin diamond grinding wheel was carried out,and the micro-topography was analyzed,the protrusion height of diamond grain was measured.The influence of laser parameters on the sharpening effect have been analyzed,including average power,pulse frequency and pulse overlap rate.Then,the sharpened wheel is also used to grind YG8 cemented carbide workpiece,to further studying the effect of laser sharpening by the grinding test results.The optimal parameters are as follows: the average laser power is 10 W,the pulse frequency is 100 kHz,and the pulse overlap rate is 50%.When optimized process parameters were employed for laser sharpening,there was a good topography on the diamond wheel,with the minimum grinding force and minimum roughness of workpiece.At last,grinding contrast and wear resistance were carried out.Through the contrast between laser method and mechanical method,it can be found that contour precision with mechanical method can be better,but in terms of topography,grinding force and surface quality of workpiece,it's better with laser method.It was verified that laser dressing was a feasible and advantageous technology of grinding wheel.Analyzing the changes in the wear of the grinding wheel during the grinding process,it was found that in the early stage of wear,the main forms of wear of the grinding wheel were grain fracture and shedding,and the amount of wear is large.In the normal wear stage,the changes of workpiece surface quality are stable,and the grinding ratio was large.In the late wear period,due to the increase of wear and heat accumulation,some areas of the grinding wheel were blocked,which affected the grinding performance.At the same time,by monitoring the change of the grinding force during the grinding process,it was found that with the increase of the cumulative grinding depth,the grinding force was gradually increasing,which reflected the law of wear of the grinding wheel.