Structuring Of Coarse-grained Diamond Wheelsurface Via Laser Machining Methods

Hard and brittle materials, such as ceramics, glasses and semiconductor materials,are widely used in the optical, automotive, and microelectronics. Well dressed coarse-grained diamond wheels can realize high efficient grinding of hard and brittle materials.However, the serious surface and subsurface damage will be inevitably introduced bythe coarse-grained wheels. Base on laser machining methods, this paper presents thepotential of a structured coarse-grained diamond wheel with micro grooves on thewheel surface for surface grinding operations aiming to improve the grindingperformance.In this paper, the experimental investigation of laser machining single graindiamond are carried out to compare the machining quality,efficiency and graphitizationby the typical nanosecond pulsed laser and femtosecond pulse laser. LDU5UVnanosecond pulsed laser are selected as the laser source in the following experiments. Itis used to machining micro grooves on single grain diamond. The influence of laserparameters to groove width and depth is investigated. Combined with laser structuringexperiments on coarse-grained diamond wheels, Some structured coarse-graineddiamond wheel are manufactured under the optimal laser parameters.Structured coarse-grained diamond wheel are used in grinding experiment. Thewheel is first properly trued with a metal bond diamond wheel with electrolytic inprocess dressing (ELID) method. Then grinding experiments are carried out on aprecision grinder. Angle polishing methods is used to measure depth of the subsurfacedamage. The generated surface and subsurface damage of BK7are characterized byprofilometer and scanning electronic microscope (SEM). The grinding forces and thesurface quality of the BK7workpieces including surface roughness(SR) and thesubsurface damage(SSD) are investigated.The results demonstrate that laser machining methods can realize the structuring ofcoarse-grained diamond wheel effectively. And comparing with the conventionalcoarse-grained wheels, the depth of subsurface cracks and the grinding force ratio canbe reduced when using the structured coarse-grained diamond wheel. However, thesurface roughness deteriorate and the density of subsurface cracks increases.