TABLE OF CONTENTS Grinding wheels and abrasive segments fall under the general category of 'bonded abrasive tools'. Such tools consist of hard abrasive grains or grits, which do the cutting, held in a weaker bonding matrix. Depending on the particular type of bond, the space between the abrasive particles may only be partially filled, leaving gaps and porosity, or completely filled with binder. Aside from abrasive and bond material, fillers and grinding-aid materials may also be added. The properties and performance of bonded abrasive tools depend on the type of abrasive grain material, the size of the grit, the bond material, the properties of abrasive and bond, and the porosity.
Grinding wheels are made from many types of grit in a wide range of sizes, in conjunction with many bond materials and compositions. 'Conventional' wheels in common use contain either aluminum oxide or silicon carbide abrasive with vitrified or resinoid bonds. 'Superabrasive' wheels with diamond and cubic boron nitride (CBN) abrasives are produced with vitrified, resin, and metal bonds. Whereas conventional abrasive wheels usually comprise the entire bonded abrasive structure throughout, the abrasive-composite on superabrasive wheels is limited to a thin rim or layer on a plastic or metal hub in order to reduce the amount of costly diamond and CBN which is needed. The different types of grinding wheels, together with the requirements of a wide variety of wheel shapes and sizes to fit all the diverse grinding machines and jobs to be done, lead to an almost endless diversity...
