Conditioning and monitoring of grinding wheels

The preparation of grinding tools is the most important enabling factor in the grinding process. It influences the material removal rate, the grinding forces, the surface quality as well as the material properties of the subsurface zone, and is the key issue for subsequent wear of grinding tools. The evolving and conventional conditioning technologies are reviewed based on technical and commercial aspects. Terms in the field of conditioning are defined. Strong emphasis today is put on the description and monitoring of the abrasive layer. For optimization of the dressing process, prediction of the grinding wheel topography and the ground surface are emerging scientific topics.

"Grinding is dressing," is the slogan that is maintained in the grinding community. It indicates besides all other process parameters, the importance of conditioning technology on the manufacturing results. The conditioning process, consisting of dressing and cleaning, determines the material removal rate, the grinding forces, the surface quality and the material properties of the subsurface zone.

Generally, the interaction between the workpiece and the surface of the grinding wheel defines the grinding process. Viewed from this aspect, the grinding wheels are composed of three elements, the abrasive grit for material contact and – removal, the intergranular space for the storage of removed material and the coolant flow, and the bond to retain the grit on the wheel.

Ceramic bonded grinding wheels contain pores within the wheel body which create the in tergranular space when dressed. For metal and resinoid bonded grinding wheels the intergranular space must be created within the dressing process. Metal bond grinding wheels are mostly used for super abrasive grains because of their improved bonding strength. From the appearance of the grinding wheel one can distinguish micro geometry and macro geometry. The macro geometry is described by a convex hull over all protruding grains in circumferential direction and average profile in meridian direction. The micro geometry is given by geometric features in the dimension of a grain or an intergranular space.