The primary attraction for producing wheels with high structure numbers is to allow the highest levels of porosity to be produced while still maintaining structural integrity. This provides for very good coolant access and chip clearance in the grinding process. However, it is very difficult to maintain green strength and the integrity of the pores […]
Рубрика: Handbook of Machining with Grinding Wheels
Natural Long Diamond Blade Tools
Prior to the introduction of synthetic needles natural long stones were used. These have trade names such as the Fliesen tool from Winter (Saint-Gobain Abrasives). Some tools of this style have multiple layers of diamonds to maximize tool life, but care needs to be taken in their design to avoid changes in dress behavior when […]
Dress Parameters for Form CBN Wheels
Hitchiner [1998, 1999] gives typical parameters for dressing of CBN wheels for grinding aircraft blades and vanes. Crush ratio values of +0.6 to +0.8 are used as for conventional wheels but infeed rates are limited to 0.1 to 0.25 mm/min or 0.03 to 0.20 pm/rev, which are 10 times less than for conventional wheels. On […]
2.2.15 Surface Roughness
Surface roughness, not surprisingly, is closely related to uncut chip thickness. RT Roughness Rt roughness is the SI parameter for maximum surface roughness, the maximum difference between peak height and valley depth within the sampling length. As a first approximation, Rt is independent of depth of cut but is dependent on vw, vs, C ■ […]
FUNDAMENTAL REMOVAL MECHANISMS
3.5.1 Microplowing, Chipping, and Breaking The removal process during the engagement of an abrasive cutting edge on the surface of a workpiece mainly depends on the physical properties between the active partners. A basic distinction can be made between three different mechanisms: microplowing, microchipping, and microbreaking (Figure 3.7). In microplowing, there is a continual plastic, […]
Recent Development of High-Speed Conventional Wheels
Segmental wheel research first began with conventional wheels in the 1970s as part of an effort to evaluate the effect of high speed [Yamamoto 1972, Anon 1979, Abdel-Alim, Hannam, and Hinduja 1980]. However, the labor-intensive manufacturing costs were not competitive for the economic gains in productivity possible at that time. However, the recent development of […]
Single Crystal White Alumina
Grain growth is closely controlled in a sulphide matrix. The alumina is separated out by acid leaching without crushing. The grain shape is nodular, which aids bond retention, while the elimination of crushing reduces mechanical defects from processing. 5.4.6 Postfusion Processing Methods As mentioned above, the type of particle reduction method can greatly affect the […]
CBN
3.4.6 Development of CBN CBN is the final and most recent of the four major abrasive types, and the second hardest superabrasive after diamond. Trade names include Borazon (from GE who first synthesized it commercially), Amborite and Amber Boron Nitride (after De Beers), or in Russian literature as Elbor, Cubonite, or P-BN. Boron nitride at […]
Multiple Pore Size Distributions
Wheel manufacturers such as Universal Grinding Wheel (Saint-Gobain Abrasives) have taken this concept further, and produced wheels with multiple pore former size distributions to create both macroporosity for high permeability and microporosity for controlled fracture of the bond. This type of wheel, with trade names such as Poros 2, has proved very effective for creep-feed […]
Grit and Cluster Tools
Finally, for the roughest dressing of large cylindrical or centerless wheels there are grit tools and cluster impregnated tools (Figure 7.12). Grit tools represent the most cost-effective dressing tool for the commonest applications using straight wheels. Clusters consist of a single layer of five to seven large natural diamonds semiexposed on a round flat surface […]