Specific grinding energy can be considered as a measure of grinding efficiency. A low specific energy implies low energy consumed to remove a given volume of material. Low specific energy allows greater removal rate before meeting the power limit. Since specific energy is proportional to the grinding forces, it usually means that removal rate can […]
Рубрика: Handbook of Machining with Grinding Wheels
. VIBRATION STABILITY
19.12.1 Definitions The following definitions are helpful in making distinctions between different types of vibrations that may be experienced in centerless grinding. 19.12.1.1 Marginal Stability Marginal stability is where waviness neither builds up nor decays as grinding proceeds without direct excitation of the marginally stable frequency. In practice, a linear system excited at a frequency […]
ULTRASONIC TECHNOLOGY AND PROCESS VARIANTS
Elastomechanical ultrasonic vibration is generated by the transformation of electric energy in piezoceramic or magnetostrictive sonic converters. A voltage generator converts a low-frequency mains voltage into a high-frequency alternating-current voltage. The generated longitudinal vibrations are periodic elastic deformations of the mechanical vibration system in the micrometer range at supersonic frequencies, that is, higher than f […]
Effect of Single Grain Forces
Wear occurs on the basis of single-grain forces and process temperatures [Marinescu et al. 2004]. Continuously sharp grain cutting edges are favorable for the grinding process and for a high grinding ratio, G. This requires microcrystalline grain splintering. Wear types depend on the thermal mechanical grain stress. Figure 9.7 presents the qualitative depiction of grain […]
Monitoring of Grinding Processes
11.1 THE NEED FOR PROCESS MONITORING 11.1.1 Introduction The behavior of any grinding process is very complex. There are a large number of input variables and the whole process is transient, that is, the mechanisms change with time. The general need for a monitoring system is expressed by Figure 11.1. 11.1.2 The Need for Sensors […]
Aeroengine Shroud Grinding Example
The application illustrated in Figure 12.1 is the internal grinding of large aeroengine shroud assemblies for aircraft engines. Traditionally, the part was ground using seeded gel (SG) abrasive, but the SG process was replaced by a vitrified CBN wheel that reduced grind cycle time by 50%. The greatest time saving was achieved by the elimination […]
Application of ZTA Ceramics
The enhanced strength and toughness of ZTA ceramics have made these materials more widely applicable and more productive than plain ceramics and cermets for machining steels and cast irons. ZTA ceramics can be used as cutting tool inserts for metal cutting applications [Sornakumar and Gopalakrishnan 1995]. Cutting inserts are made by sintering followed by grinding […]
Hydrostatic Slideway Materials and Manufacture
Generating the necessary tolerance on any slideway system can be expensive and time consuming. The ways are either cast into the base and ground and/or are scraped, or the base is ground and ways bought “off-the-shelf” are bolted on. Grinding a base requires a significant investment in capital equipment for a slideway grinder while scraping […]
Spindle Bearings for HEDG
Grinders for high efficiency deep grinding (HEDG) and superabrasive high-speed grinding with plated wheels have been influenced strongly by machining center design. In many cases, the grinders are, in fact, a multipurpose machining/grinding/drilling center. The wheels are designed around sizes of 125 mm up to 300 mm running at up to 120 m/s. Numerous machine […]
The Influence of Feedrate (Workspeed)
Alongside infeed (i. e., depth of cut), the feedrate considerably affects the total machining time in reciprocating grinding. Increasing the feedrate results in higher average chip thickness and length, and thus in an increase of grinding forces and thermal stress. A repeated start of the grinding wheel to the workpiece and the punctual impact stresses […]