Хонинговальные головки

4.1 INTRODUCTION 4.1.1 Developments in Productivity Huge increases in productivity have been achieved in recent decades due to advances in grinding wheel technology. These increases have only been possible by parallel developments in the machines and auxiliary equipment employed since the greatest gains have been from the grinding system. Grinding wheels operating at low wheel […]

The current limit for steel-cored vitrified CBN wheels due to stresses in the abrasive layer from core expansion is considered to be 200 m/s. This will vary somewhat depending on the particular bond and layer depth. However, for speeds of 160 m/s and greater the steel is sometimes replaced with a material of comparable elastic […]

The principal crystallographic planes of diamond are the cubic (100), dodecahedron (011), and octahedron (111). The relative rates of growth on these planes are governed by the temperature and pressure conditions, together with the chemical environment during both growth and, in the case of natural diamond, possible dissolution during its travel to the earth’s surface. […]

Research is accelerating both in existing alumina-based grain technology and in new ultra-hard materials. In the group of ceramic-processed alumina materials, Saint-Gobain released SG in 1986 [U. S. Patent 4,623,364] followed by extruded SG in 1991 [U. S. Patent 5,009,676]. More recently in 1993, Treibacher released an alumina material with hard filler additives [U. S. […]

For superabrasive wheels, phenolic resin bonds represent the earliest, and most popular, bond type particularly for diamond wheels and especially for tool-room applications. The bonds were origi­nally developed for diamond with the introduction of carbide tooling in the 1940s. Their resilience made them optimal for maintaining tight radii while withstanding the impact of interrupted cuts […]

7.5.1 Introduction The rules for dressing vitrified CBN wheels are similar in many ways to those described for conventional wheels. The same concepts of crush ratio, traverse rates, effective contact width, and depth of cut apply. The changes that must be made to the dressing conditions relate to the greater hardness, toughness, and cost of […]

The importance of the abrasive cannot be overemphasized. The enormous differences in typical hardness values of abrasive grains are illustrated in Table 1.1 [after De Beers]. A value for a typical M2 tool steel is given for comparison. The values given are approximate since variations can arise due to the particular form, composition, and directionality […]

An increasingly popular approach to control thermal damage has been developed by Malkin [1989] with literature examples of its application in industry by General Motors on cast iron [Meyer 2001], with Bell Helicopter on hardened steel, and [Stephenson et al. 2001] on Inconel to impose a limit on grinding temperatures. Malkin [1989] provides the maximum […]

In the next few chapters, the distinction will be made repeatedly between operation with conven­tional abrasives such as alumina and silicon carbide and operation with superabrasives such as CBN and diamond. The wheel designs tend to be distinctly different. One reason is the expense of the raw materials used for diamond and CBN superabrasives. Another […]

Aircraft grade aluminum alloys are used as hub materials for some high-speed vitrified CBN. The obvious attraction is the lower density relative to steel. Various grades are available with tensile strengths of 120 to 140 kpsi. However, they have higher thermal expansion and appear to give more size and stability problems. 4.6.8 Junker Bayonet Style […]