Structure and Properties of Bakelite Bonded Grinding Wheels

The composition of each grinding wheel depends on the specific application, and nowadays, there are many types of grinding wheels on the market. Bakelite bonded grinding wheels are fast becoming the standard choice for grinding and finishing processes in automotive, aerospace and other special fields of industry. Increasing requirements on higher quality and lifetime push manufacture to continuous research and development in this field. From that reason, it is necessary to characterize the structure and properties of already produced commercial grinding tools. In this contribution, two in chemical composition identical bakelite bonded grinding wheels with different properties were studied. Processing parameter like compression force is the main factor resulting in either hard grinding wheel for machining soft materials or soft grinding wheel for machining hard materials. The main components of both grinding wheels are abrasive particles of brown alumina (Al2O3) and two bonding agents based on synthetic rubber and bakelite. In addition, grinding wheels contain additives, e.g. vulcanization accelerators, fillers etc. to improve functional properties of grinding wheel. Fractures and metallographic samples morphology was studied by scanning electron microscopy. Porosity of grinding wheels was estimated using image analysis. Hardness of binder and abrasive brown alumina particles was measured by Rockwell hardness test.