6.5.1 Overview on Conditioning Principles
Grinding wheel topography is influenced by grinding wheel structure, profiling and sharpening process as well as by the wear during the use of the grinding wheel [MARI04]. The dressing process changes the working behavior of the grinding tool, the Young’s modulus and the effective hardness of the grinding layer [MARI04]. In addition, the abrasive layer will change during the grinding process [STUF96]. The dressing process should enable a grinding process as consistent as possible considering grinding wheel wear.
Abrasive tools are prepared for use to be set up for a new grinding application according to profile and micro topography, to true their roundness deviation and to compensate their wear. The term “dressing” envelopes the processes of “profiling” or “truing”, i. e. the generation of the demanded grinding tool profile, and “sharpening”, i. e. the generation of cutting ability [KLOC05a, SPUR89, TONS04]. Sometimes “dressing” refers only to sharpening. Depending on abrasive tool specification and machine set-up, profiling and sharpening have to conducted as separate processes. In general, dressing consumes a lot of grinding wheel volume [STET74], sometimes up to 90 % of the grinding wheel volume.
The various dressing methods can be organized by different criteria, such as active medium, active principle, or process kinematics [HESS03, KLOC05a, SPUR89, LINK07]. Active dressing media can be with or without diamond. Active principles are cutting of grits and bond, setting back the bond, or removing the bond. To set back the bond, diamond free tools like steel rollers, silicon carbide wheels, or sharpening tools of bonded abrasives are used. Material removal processes are restricted to metallic bonds and work with electro-chemical or electro discharge processes [SPUR89]. In laser conditioning, bonding is vaporized before the abrasive grits are harmed [SHAW96]. Laser assisted dressing is a hybride procedure. The laser beam softens vitrified bonding to support dressing with diamond tools [ZHAN03]. Sand blasting is used for bond sharpening at honing sticks. The applied dressing strategy always depends on quality and cost requirements and the available machine concept. Wegener et al. [WEGE11] give a detailed overview on profiling and sharpening strategies.