Sintered corundum can be also produced from fused corundum, which is crushed and sintered with auxiliary agents such as glass phase agents [KLOC05a, p. 25]. 2.1.3 Manufacture of Corundum by Sol-Gel Process Sol-Gel corundum is produced by the sol-gel procedure and a subsequent pressure-less sintering procedure (Fig. 2.8) [KLOC05a, p. 25]. The crystal sizes are […]
Рубрика: Life Cycle and Sustainability of Abrasive Tools
Other Types of Abrasives
2.5.1 Natural Abrasives Before the development of appropriate grit synthesis methods, natural abrasives were used. Today, some natural materials are still used for polishing applications. The disadvantages of natural abrasives are their lower strength with the exception of natural diamond, as well as the non-reproducible grit quality [KLOC09, p. 17]. Quartz (silica, SiO2) includes the […]
Toughness and Breaking Behavior Analysis
2.9.3.1 Friatest Manufacturers of superabrasives evaluate the grit fracture behavior by impact strength tests, so called friability test or friatester [ODON76, MARI04]. A grit sample with a defined weight and a steel ball are encased in a capsule, which is then shaken with a defined cycle number [VOLL12]. The impact load breaks a portion of […]
Performance of Resin Bonds
Resin bonds have comparably high elasticity. Therefore, this bond type is selected for wheels that are subject to impacts, sideways load, sudden loads, or high cutting speeds. Typical applications are cut-off or roughing operations. In addition, resin bonds work well for finishing processes to achieve high surface quality. Bond elasticity, however, might have a negative […]
Performance of Metallic Single-layered Bonds
In general, electroplated wheels have just one layer of abrasive grits. Therefore, tool life can be a major determining factor and grit strength is of major relevance. The range of characteristics available in diamond grit types is considerably wider for metal bonds than for use in other bonding systems. Often high strength crystalline diamond types […]
Tools for Abrasive Sawing
The biggest volume of diamond saws is used in cutting stone and refractory materials. Abrasive wires and saws are also used in the electronics and solar industry to cut silicon and quartz crystals into wafers. In Multi-Wire-Slicing, a wire is led by several coils to form several wire lines, which cut simultaneously [KLOC09, p. 386]. […]
Connection Between Abrasive Layer and Body
Four major processes connect the abrasive layer with the tool body: adhesive sealing, sintering, shrinking, and electroplating [KRAF08]. With electroplating, the Table 5.3 Mechanisms in connecting abrasive layer and body [MARI04, p. 212] Resin bonded layer Vitrifed bonded layer Electroplated layer Sintered metal bonded layer Metal body Adhesion Adhesion Cohesion Cohesion Ceramic body (rare:adhesion) Cohesion […]
Kinematic Cutting Edge Density
Kinematic cutting edges or grits are only those of the static edges or grits engaging into the workpiece material (Fig. 6.5). The kinematic grit number, Nkin, can be counted at small contact forces so that the tool contact deformation is negligible [ISO89]. Equation 6.9 offers an empirical approach to calculate the number of kinematic grains […]
Dressing Parameters
6.5.3.1 Overlap Ratio Overlap ratio, Ud, is an important metric for dressing processes with axial feed rate [SALJ84]. It indicates how frequently the dressing tool overtravels a point on the grinding wheel. Overlap ratio is calculated from engagement width of the dressing tool, apd, and axial feed per grinding wheel revolution, fad (Eq. 6.24). (6.24) […]
Implications of a Bonded Tool
The design parameter of a bonded tool implies that an initial tool profile needs to be defined and then maintained as well as an initial tool sharpness needs to be defined and maintained (Fig. 7.13). Design parameters to define profile and sharpness are profiling and sharpening respectively. Profiling and sharpening can be combined to one […]