The first vitrified bonded wheels were considered as inappropriate for large temperature variations because the bond was not elastic enough to withstand thermal expansion differences within the tool [KING86, p. 87]. Certain bond elasticity is important to equalize the volumetric expansion of the abrasive grits induced by the grinding process heat [STAD62, p. 51]. Vitrified […]
Рубрика: Life Cycle and Sustainability of Abrasive Tools
Tool Grinding Wheels
Tool steels and high-speed steels are machined with corundum or CBN wheels [LINK09, KONI80]. Carbides and ceramic tools are ground mainly with silicon carbide or diamond wheels. Diamond grit sizes for carbide tool grinding wheels lie commonly between D46 and D181 [FRIE02, p. 46]. Diamond grits with low toughness enable self-sharpening during the grinding process, […]
Single Layer Plated Tools
Electroplated diamond grinding tools exhibit potential for recycling. In particular, the body can be reused. Electroplated grinding wheels are generally returned to the manufacturer, who will strip off the abrasive layer and re-plate the body. Usually chemical and electrochemical stripping methods are used [BULJ99]. Chemical methods such as acid baths corrode the bonding [BULJ99, YU11]. […]
Hardness Testing by Grit Breakout Test or Scratch Test
Merbecks developed the grit breakout test and scratch test following ideas from Opitz and Peklenik [MERB03, PEKL60]. These tests are well applicable to superabrasive grinding tools as they do not damage the abrasive layer, leave holes, or measure the whole body elasticity [KLOC05c, MERB03]. In the single grit breakout test, a cemented carbide tip is […]
G-Ratio
Tool life between conditioning is measured in time, per number of machined workpieces or workpiece volume removal [PAUC08, p. 343]. The G-ratio is a common parameter for describing the tool lifespan as ratio of machined workpiece volume, Vw, and worn grinding tool volume, Vs (Eq. 6.20) [MALK08]. The G-ratio depends on the machined material, tool […]
Life Cycle Engineering
Companies have to find ways to capture and measure their sustainability performance. The overall goal of sustainability encompasses the three dimensions of economic, environmental and social sustainability [HAUS05]. Life Cycle Costing (LCC), Life Cycle Assessment (LCA), and Social Life Cycle Assessment (SLCA) are methods to assess each dimension. Sustainability indicators evaluate the overall performance in […]
Matrixes from Axiomatic Model
All discussed effects produce a complex grinding process model. This axiomatic model, however, is simplified and based on existing models. The main application is fine grinding of ductile material, leaving exemptions, special process variants and Fig. 7.32 Low scrap rate (diagram follows Fig. 7.30) other applications open. Experimental data, sensitivity analyses and empirical data could […]
Options for Tool Manufacturers
In the long run, the manufacturing paradigm has to shift from non-sustainable mass production, mass consumption, and mass disposal to sustainable environmentally conscious ones [UMED12]. The eco-efficient layout of manufacturing processes and products will be a core competency for engineers in the future. It is important to integrate all the life cycle phases from the […]
Toughness, Breaking Behavior, Friability
The density of atom bonds in the different diamond planes defines hardness and cleavage behavior (Fig. 2.15) [BRUN62, FIEL79]. The octahedral plane (111) is the main cleavage plane [FIEL81, LENZ86]. This can be explained by the lower toughness and, therefore, smaller necessary breakage energy along this plane Cubic plane (100) Rhombic dodecahedral
Hardness and Temperature Hardness
The hardness of abrasives is defined in terms of the static indentation hardness as determined by Knoop or Vickers hardness test [MALK08]. Chip formation needs a high degree of grit hardness and toughness [KLOC05a]. Moreover, cutting edge sharpness over a longer period is affected by the grit hardness and wear resistance. There is no direct […]