7.4.1 Introduction Rotary diamond tools were the industry’s answer to life issues with stationary tools and are in many ways the rotary equivalents to single points, blades, grit tools, and form blocks. A rotary diamond tool (also called “truer,” “dresser,” or “roll”) consists of a disc with diamond in some form held on the periphery […]
Рубрика: Handbook of Machining with Grinding Wheels
Forced Vibration
Out-of-balance and eccentricity of the grinding wheel are the main causes of forced vibrations [Inasaki and Yonetsu 1969, Gawlak 1984]. The wheel, as a source of vibration, can be relatively easily identified through frequency measurement. The main concern with wheel-induced vibration is how to eliminate out-of-balance and wheel runout. There are a number of other […]
BASIC USES OF GRINDING
Grinding is a key technology for production of advanced products and surfaces in a wide range of industries. Grinding is usually employed where one or more of the following factors apply. 1.2.1 High Accuracy Required Grinding processes are mostly used to produce high-quality parts to high accuracy and to close tolerances. Examples range from very […]
Grinding temperatures
2.3.1 Surface Temperature T Prediction of grinding temperatures and the avoidance of burn are critical to grinding quality. Numerous calculations modeling the partition of heat between the elements in the grind zone have been developed over the last 50 years. Maximum temperature of the workpiece is usually based on anoriginal paper by Jaeger [1942] and […]
Coarse-Grained Materials
In the case of coarse-grained materials, the removal processes take place in a different way. A sharp diamond plastically divides the grains in the structure under high energy input. With increasing infeed cracks develop mainly along the grain boundary. This is accompanied by intercrystalline failure, which leads to a break-off of grains near to the […]
High-Speed Wheel Mounts
With high-speed steel-cored wheels the need for blotters is eliminated. Clamping is, therefore, steel on steel and not prone to the same brittle failure from stress risers. Nevertheless, there is the uncertainty on wheel contraction and its effect on clamping. One solution is to eliminate the flanges entirely. Landis (Waynesboro, Pennsylvania) developed a one-piece wheel […]
Future Trends for Conventional Abrasives
With time, it is expected that SG, TG/TG2, Cubitron, and other emerging chemical precipitation/sin — tering processes will increasingly dominate the conventional abrasive market. The production of electrofused product is likely to shift more and more from traditional manufacturing sites with good availability of electricity, such as around the Great Lakes of the United States […]
Thermal and Chemical Stability of CBN
CBN is thermally stable in nitrogen or vacuum to at least 1,500°C. In air or oxygen, CBN forms a passive layer of B2O3 on the surface, which prevents further oxidation up to 1,300°C. However, this layer is reactive with water, or more accurately high temperature steam at 900°C, and will allow further oxidation of the […]
Grades of CBN Wheels
A comparison with porosity levels in Figure 6.8 shows clearly that the grade of CBN wheel for a given application, even with the development of higher porosity structures, is much denser than for conventional wheels. This is hardly surprising as CBN is so expensive it must be held for a much greater period of time, […]
Single-Ring Diamond and Matrix Diamond Discs
The rotary diamond differs from a stationary tool in that it is not cutting a continuous thread in the wheel, but, consisting as it does of a ring of exposed diamond points, it is cutting a series of Wheel/grit contact length ld FIGURE 7.18 Wheel surface appearance generated by a single diamond ring rotary truer […]