The Experimental Studies Of Dressing Of Bronze-bonded Diamond Grinding Wheels Using A Pulsed Fiber Laser And Grinding Characteristics

With excellent grinding performance, bronze-bonded diamond grinding wheelsare widely applied in the fields of difficult-to-cut material grinding, form grinding,precision grinding, ultra-precision grinding, high speed grinding, high efficiencygrinding and grinding automation. Precisely truing and dressing of bronze-bondeddiamond grinding wheels, however, is very difficult which seriously affected grindingperformance and the application of bronze-bonded diamond grinding wheels. As apromising method, laser dressing of super-abrasive grinding wheels is based on themechanism of laser ablation for materials. In this thesis, dressing of bronze-bondeddiamond grinding wheels using a pulsed fiber laser has been studied.Firstly, a ytterbium-doped fiber laser was chosen according to the test needs, andthe performance parameters such as the average output power, focus spot as well aspulse width were tested, which laid a foundation for quantitative analysis of thedressing experiments.Then, experimental studies have separately carried on, in which bronze bondsand diamond grits with single pulse laser ablation, and diamond grits with multiplepulse were ablated to obtain ablation crater depth of bronze bonds and surfacetopography of diamond grits under the condition of different laser parameters. As aresult, dressing of bronze-bonded diamond grinding wheels using a pulsed fiber laseris feasible and superior, which can not only remove bronze bonds precisely andeffectively but also don’t damage diamond grits.Secondly, instead of bronze-bonded grinding wheel, bronze bond wheel was usedto perform laser dressing process experiment to obtain a set of optimal laserparameters and process parameters combination of a fiber laser dressing ofbronze-bonded diamond wheels. With the optimized laser parameters (the averagepower:20W, pulse repetition frequency:70kHz, the defocus distance:0mm) and theoptimal process parameters (speed of grinding wheel:203r/min, feed speed:0.09mm/s,side air pressure:0.6MPa), a good grinding wheel surface topography was obtained.Finally，the two bronze-bonded diamond grinding wheels after laser dressing andEDM dressing were both used to grind the alumina ceramic. The different effectsbetween the two dressing methods were compared with grinding forces, grindingforce ratios, surface roughnesses and surface microscopic morphology of the grinding workpiece, as well as surface morphologies of the two bronze-bonded diamondgrinding wheels before and after the grinding. It is shown from the experimentalresults that dressing of bronze-bonded diamond wheels using a pulsed fiber laser canobtain good dressing effect and grinding performance.