Хонинговальные головки

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 […]

By controlling the growth conditions, especially time and nucleation density, it is possible to grow much higher quality stones with well-defined crystal forms: cubic at low temperature, cubo — octahedra at intermediate temperatures, and octahedra at the highest temperatures. The diagram for growth morphologies of diamond is shown in Figure 5.9. The characteristic shape of […]

6.1 INTRODUCTION Wheel bond systems can be divided into two types: those holding a single layer of abrasive grain to a solid steel core, and those providing a consumable layer many grains thick with the abrasive held within the bond. The latter may be mounted on a resilient core or produced as a solid monolithic […]

5.11.1 Introduction Polyimide resin was developed by DuPont in the 1960s originally as a high-temperature lacquer for electrical insulation. By the mid 1970s, it had been developed as a cross-linked resin for grinding wheels giving far higher strength, thermal resistance, and lower elongation than conventional phenolic bonds. The product was licensed to Universal Diamond Products […]

Crush ratio can have a profound effect on the dressing action. Ishikawa and Kumar [1991] reported a study on dressing of vitrified bonded wheels containing coarse grade 80# GE 1 abrasive. They distinguished between three forms of grit fracture: “micro,” “medium,” and “macro” as illustrated in the micrographs in Figure 7.21. It was determined that […]