Slide 1Examples of Bonded AbrasivesWorkpiece GeometriesGrinding WheelCommon Grinding WheelsSuperabrasive Wheel ConfigurationGrinding ChipsGrinding Wheel SurfaceSurface grinding and PlowingShaping using Computer ControlSurface Grinding OperationsSurface GrindingCylindrical Grinding OperationsSlide 14Thread and Internal GrindingCycle Pattern in Cylindrical GrindingCenterless GrindingCreep-Feed GrindingUltrasonic Maching and Coated AbrasivesBelt GrindingHoning and SuperfinishingLappingPolishing Using Magnetic FieldsAbrasive Flow MachiningRobot DeburringCHAPTER 25Abrasive Machining and Finishing OperationsExamples of Bonded AbrasivesFig: A variety of bonded abrasive used in abrasive machining processesWorkpiece GeometriesFig: The types of work pieces and operations typical of grinding: (a) cylindrical surfaces, (b) conical surfaces, (c) fillets on a shaft, (d) helical profiles, (e) concave shape, (f) cutting off or slotting with thin wheels, and (g) internal grindingGrinding WheelFig: Physical model of a grinding wheel, showing is structure and wear and fracture patterns.Common Grinding WheelsFig: Common Type of Grinding Wheels made with conventional abrasives. Note that each wheel has a specific grinding face; grinding on other surfaces is improper and unsafeSuperabrasive Wheel ConfigurationFig: Examples of Superabrasive Wheel Configuration. The annular regions (rim) are superabrasive grinding surfaces, and the wheel itself (core) is generally made of metal or composites. The bonding materials for the super abrasives are: (a), (d), and (e) resinoid, metal, or vitrified, (b) metal, (c) vitrified, and (f) resinoidGrinding ChipsFig: (a) Grinding chip being produced by a single abrasive grain. (A) chip, (B) workpiece, (C) abrasive grain. Note the large negative rake angle of the grain. The inscribed circle is 0.065mm in diameter. (b) Chip formation by an abrasive grain with a wear flat. Note the negative rake angle of the grain and the small shear angleGrinding Wheel SurfaceFig: The surface of a grinding wheel showing abrasive grains, wheel porosity, wear flats on grains, and metal chips from the workpiece adhering to the grains. Note the random distribution and shape of abrasive grains.Surface grinding and PlowingFig: Surface grinding process, showing various process variables.Fig: Chip formation and Plowing of the workpiece surface by and abrasive grain. This action is similar to abrasive wearShaping using Computer ControlFig: Shaping the grinding face of a wheel by dressing it with computer control. Note that the diamond dressing tool is normal to the surface at point of contact with the wheel.Surface Grinding OperationsFig: Surface Grinding Operations. (a) Traverse grinding with a horizontal-spindle surface grinder. (b) Plunge grinding with a horizontal-spindle surface grinder, producing a groove in the workpiece. (c) A vertical-spindle rotary-table grinder (also known as the Blanchard type)Surface GrindingFig: (a) Rough grinding of steel balls on a vertical-spindle grinder; the balls are guided by a special rotary fixture. (b) The balls are ground to within 0.013mm of their final size.Fig: A Horizontal-spindle surface grinderCylindrical Grinding OperationsFig: Examples of various cylindrical grinding operations. (a) Traverse grinding, (b) plunge grinding, and (c) profile grinding.Plunge and Noncylindrical GrindingFig: Plunge Grinding of a workpiece on a cylindrical grinder with the wheel dressed to a stepped shape.Fig: Grinding a noncylindrical part on a cylindrical grinder with computer controls to produce the shape. The part rotation and the distance x between centers is varied and synchronized to grind the particular workpiece shape.Thread and Internal Grinding Fig: Thread grinding by (a) traverse, and (b) plunge grindingFig: Internal grinding operationsCycle Pattern in Cylindrical GrindingCenterless GrindingFig: Centerless grinding operations: (a) through feed grinding. (b) Plunge grinding. (c) A computer numerical control grinding machineCreep-Feed GrindingFig: (a) Creep-Feed Grinding process. Note the large wheel depth of cut, d. (b) A shape groove produced on a flat surface by creep-feed grinding in one pass. Groove depth is typically on the orde of a few mm. (c) An example of creep-feed grinding with a shaped wheel. This operation can also be performed by some of the processes described .Ultrasonic Maching and Coated AbrasivesFig: (a) Ultrasonic Maching process. (b) and (c) Types of parts made by this process. Note the small size of holes producedFig: Structure of a coated abrasive.Sandpaper, developed in the 16th century, and emery cloth are common examples of coated abrasivesBelt GrindingHoning and SuperfinishingFig: Honing tool used to improve the surface finish or ground holesFig: The Superfinishing process for a cylindrical part. (a) Cylindrical microhoning, (b) Centerless microhoningLappingFig: (a) Lapping process. (b) Production lapping on flat surfaces. (c) Production lapping on cylindrical surfaces.Polishing Using Magnetic FieldsFig: Polishing of balls and rollers using magnetic fields. (a) Magnetic float polishing of ceramic balls. (b) Magnetic-field-assisted polishing of rollers.Abrasive Flow MachiningFig: Abrasive Flow Machining to deburr a turbine impeller.The arrows indicate movement of abrasive media. Note the special fixture, which is usually different for each part design.Robot DeburringFig: A Deburring operation on a robot-held die-cast part for an outboard motor housing, using a grinding wheel. Abrasive belts or flexible abrasive radial-wheel brushes can also be used for such