Pulsed Laser Ablating Temperature Field Simulation And Dressing Experimental Study For Bronze-bonded Diamond Grinding Wheel

With excellent grinding performance, the super-abrasive grinding wheels arewidely applied in the fields of precision grinding, ultra-precision grinding anddifficult-to-cut material grinding. However, the truing and dressing process ofsuper-abrasive grinding wheel is very difficult, which really affects the full exertionof the grinding performance of super-abrasive grinding wheel to a certain extent. As aprospective method, Laser truing and dressing of super-abrasive grinding is based oninteraction between laser and matter-thermal effect, which can bring mass transfer ofmaterial when laser irradiating the grinding wheel surface. Laser truing and dressingbronze-bond diamond wheel is studied in this paper, one use bronze-bond diamondwheel for test object and pulsed laser as dressing tool.Firstly, an acoustic-optic Q-switched Nd: YAG laser has been self developed, andperformance of the laser has been tested. The results show that the maximum averagepower can reach200W, and the range of pulse duration was about150ns~1000ns.Secondly, based on the reasonable hypothesis, simulation models of singlepulsed laser ablating bronze and diamond temperature field are established by finiteelement method, which show the temperature distribution of bronze and diamondunder different laser power density. Reasonable laser parameters are obtained fromthe temperature distribution contours: the pulsed laser power density ranging from1.66×10~7~7.5×10~7W/cm~2is suitable for dressing; the value ranging from9.95×10~7~3.52×10~8W/cm~2is suitable for truing. By virtue of simulation results, themechanism of pulsed laser truing and dressing bronze-bond and diamond grindingwheel is further analyzed, which can be explained as follow: with appropriate laserpower density in the air medium, the brozen-bond is gasificated, and the diamond isoxidized and burnt.Subsequently, experiments are conducted using pulsed laser to true and dress abronze-bond diamond wheel with suitable laser parameters. After truing and dressingfor8~9hours, the circular run-out error of the grinding wheel surface decreases from450μm to20μm, and eccentricity is almost eliminated. In addition, surface qualityvariation of the bronze-bond diamond wheel during the laser truing and dressingprocess is emphatically analyzed. The results show that, good surface quality can beobtained by laser truing and dressing. Finally, the brozed-bond diamond wheel dressed by pulsed laser is put to grindthe specimen, which is made of YT5cemented carbide. Grinding forces produced inthe grinding process are measured; moreover, the grinding performance and abrasioncharacteristic of the experimental wheel are analyzed. Meanwhile, contrastexperiments using a brozen-bond diamond wheel dressed by mechanical method arecarried out. It is shown from the contrast experiments that, the grinding performanceof the brozen-bond diamond dressed by laser is relatively superior, and not easy topassivate.