Corundum (a-Al2O3) and water (H2O) can result in gibbsite (Al(OH)3, Eq. 2.1) or diaspore (AlO(OH), Eq. 2.2) [LUDE94, p. 77]. The reaction to the relatively soft gibbsite in Eq. 2.1 is likely at temperatures from 0 to 300 °C and pressures up to 1000 bar [LUDE94, p. 79]. Al2O3 + 3H2O! 2 Al(OH)3(gibbsite, Knoop hardness […]
Рубрика: Life Cycle and Sustainability of Abrasive Tools
Honing Tools
Other than in grinding, diamond has far fewer limitations when machining steel by honing. This can be explained by the low cutting speeds, cooling and lubrication conditions in honing, which tend to suppress the reaction between diamond and workpiece materials with carbon affinity [KOPP81]. 2.3.4.2 Dressing Technology Natural diamonds of high purity are commonly used […]
Counting Methods
Counting methods work for single particles or on their projection [SALM07, p. 140]. A common procedure for counting abrasive grits is laser granulometry. Herein, a mixture of loose samples in a fluid medium flows through a ring. Laser light leads to different shadowing effects depending on the grit size. Commonly, three proportions of different grit […]
Manufacturing of Resin Bonds
Resin bonded grinding tools are manufactured via mixing, pressing and hardening at temperatures up to 200 °C (Fig. 3.5) [COLL88]. Resins consist normally of the two main components resin and hardener. Mixing both parts results in the reactive resin material. During hardening, the resin’s viscosity rises and a duroplastic material is generated. 3.1.2.1 Mixing and […]
Manufacturing of Electroplated Bonds
Electroplating is based on the cathodic metal deposition from a watery electrolyte (Fig. 3.15). A metallic layer can only be deposited on a workpiece, if there are enough electrons to discharge the metal ions within the watery solution. Depending on the origin of the electrons, a distinction is drawn between chemical metal deposition (without external […]
Abrasives for Polishing
Abrasives for polishing processes tend to be chosen according to the desired material removal rates. Common grit sizes are around 1 pm [MARI04, p. 442]. In rough abrasive pastes, the following abrasives with higher hardness are used [MARI04, p. 381, BORK92, p. 11, 13, 20, DAMB05, p. 33]: • Diamond (C), • Magnesia (MgO), • […]
Metal Body
Metallic bodies made of steel, aluminum, aluminum resin composite, bronze, and copper are applied. For example, the aluminum and bronze blanks are turned to the proper dimensions on a lathe as bodies for resin bonded wheels [METZ86, p. 62]. The turning operation is a big portion of the manufacturing costs, because dimensional accuracy ranges from […]
Abrasive Layer Composition
6.1.1 Volumetric Composition The percentages of grit volume, VG, bond volume, VB, and pore volume, VP, add up to 100 % (Eq. 6.1). The mass, m, of the abrasive layer is composed of the grit mass and bonding mass, defined by their respective densities, pG and pB (Eq. 6.2). Vg + Vb + Vp = […]
Clogging of the Abrasive Layer
Clogging or loading of the abrasive layer describes the adhesion of chips to the abrasive grits or interlocking of chips in the pore space. With more wheel clogging, the danger of thermally induced damage of the workpiece surface layer, the workpiece roughness and the grinding wheel wear rise [LAUE79]. Lauer-Schmaltz [LAUE79] pointed out that the […]
Input-Output Streams of Grinding
The complex tool design with multiple cutting edges and the complex chip formation mechanisms complicate the analysis of the grinding process [KLOM86]. Figure 7.7 shows all input and output streams that can be considered in grinding and provides a basis for a life cycle inventory. The items have different relevance for different applications. The tooling […]