Search Results for precision grinding

Metal is removed from the workpiece by the mechanical action of irregularly shaped abrasive grains in all grinding operations. This article discusses three primary components of grinding wheels, namely, abrasive (the cutting tool), bond (the tool holder), and porosity or air for chip clearance and/or the introduction of coolant. It describes the compositions and applications of coated abrasives and types of grinding fluids, such as petroleum-base and mineral-base cutting oils, water-soluble oils, synthetic fluids, semisynthetic fluids, and water plus additives. The article concludes with information on different types of grinding processes, namely, rough grinding, precision grinding, surface grinding, cylindrical grinding, centerless grinding, internal grinding, and tool grinding.

In all grinding operations, care must be used in the selection of wheels and abrasive belts to meet finish and tolerance requirements without damaging the workpiece. This article discusses the major aspects of the grinding wheel, including production methods, selection considerations, standard marking systems, abrasives, and bonding types. It compares bonded wheel grinding with abrasive belt grinding. The article reviews the types of grinding fluids and discusses their importance in grinding operations. It describes the specific grinding processes and provides recommendations for grinding and grinding wheels.

Superabrasives collectively refer to the diamond and cubic boron nitride (CBN) abrasives used in grinding applications. This article discusses the classification of superabrasive wheels according to a variety of sizes and shapes, construction, concentration, and bond systems. It provides information on the applications of the superabrasive wheels depending on the factors of the grinding system. These factors include machine tool variables, work material, wheel selection, and operational factors. The article describes the methods available for superabrasive wheel truing in production grinding operations, namely, stationary tool, powered, and form truings. It reviews the truing methods, such as truing with abrasive wheels and hard ceramics, for batch production. The article explains practical methods available for dressing CBN wheels, namely, abrasive stick, abrasive-jet, slurry, and high-pressure waterjet dressing. It concludes with information on the conditioning process of the CBN wheel.

Abrasive finishing is a method where a large number of multipoint or random cutting edges are coupled with abrasive grains as a bond or matrix material for effective removal of material at smaller chip sizes. This article provides a broad overview of the various categories of abrasive products and materials, abrasive finishing processes, and the mechanisms of delivering the abrasives to the grinding or machining zone. Abrasive finishing processes, such as grinding, honing, superfinishing, microgrinding, polishing, buffing, and lapping, are discussed. The article presents a brief discussion on abrasive jet machining and ultrasonic machining. It concludes with a discussion on the four categories of factors that affect the abrasive finishing or machining: machine tool, work material, wheel selection, and operational.

Ceramics usually require some form of machining prior to use to meet dimensional and surface quality standards. This article focuses on abrasive machining, particularly grinding, and addresses common methods and critical process factors. It covers cylindrical, centerless, and disk grinding and provides information on tooling, wheel selection, work material, and operational factors. It also discusses precision slicing and slotting, lapping, honing, and polishing as well as abrasive waterjet, electrical discharge, laser, and ultrasonic machining.

This article discusses the principles of grinding process. It illustrates a typical wheel-work characteristic chart relating surface finish, wheel wear rate, metal removal rate, and power to the normal force. The article also reviews the effect of variations in work material, wheel specification, wheel speed, coolant, and grinding wheel-work conformity on the slopes of the wheel-work characteristic chart.

This article focuses on the influence of various work material properties, namely, hardness; toughness; stiffness; ductility; thermal, electrical, and magnetic properties; and microstructure effects on finishing methods. It also addresses the relative response of work materials, such as metals, ceramics, and composites, to grinding.

Electrical discharge grinding (EDG) is much like electrical discharge machining except that the electrode (tool) is a rotating graphite wheel. This article commences with a schematic illustration of a setup for EDG wheels and discusses the control operation of the EDG setup. It tabulates typical applications and conditions for the EDG of stainless steels using 300 mm diameter wheels. The article describes the process characteristics of the EDG in terms of applications, surface finish, corner radius, and wheel wear. It concludes with a graphical illustration of the effect of heat in electrical discharge grinding on the surface hardness of various work metals.

This article discusses the various elements of thread grinding processes, including thread grinding machines, tolerances, wheel selection, grinding speed, and grinding fluids. It describes truing of grinding wheels and reviews the process applications. In addition, the article describes the five basic methods employed for cylindrical thread grinding, namely, single-rib wheel traverse grinding, multirib wheel traverse grinding, multirib wheel plunge grinding, multirib wheel skip-rib, or alternate-rib, grinding, and multirib wheel three-rib grinding. It also provides an overview of centerless grinding of threads and high-volume applications of thread grinding.

This article focuses on the various technology drivers for finishing methods, namely, tolerance, consistency, surface quality, and productivity. Every finishing method may be viewed as a manufacturing system consisting of four input categories: machine tool, processing tool, work material, and operational factors. The article provides a classification of finishing as a surface generation process and addresses the characteristics of the generated surfaces and the methods used to measure them. It describes the thermomechanical interactions occurring between the processing tool and the work material in the presence of machine tool and operational factors.

Mechanical finishes usually can be applied to aluminum using the same equipment used for other metals. This article describes the two types of grinding used in mechanical finishing: abrasive belt grinding and abrasive wheel grinding. It reviews the binders and fluid carriers used in buffing, and discusses satin finishing and barrel finishing. It also describes lapping and honing techniques that are of special interest in treating aluminum parts that have received hard anodic coatings. Honing recommendations for aluminum alloys are presented in a table.

The concept of surface integrity for grinding operations can be extended to encompass six different groups of key factors: visual, dimensional, residual stress, tribological, metallurgical, and others. This article discusses the importance of these factors in the performance and behavior of finishing methods in various manufactured parts. Special emphasis is given to residual stresses and their influence on the final mechanical properties of a manufactured part.

This article focuses on precision and ultraprecision finish machining techniques that make use of defined cutting edges, such as polycrystalline diamond and cubic boron nitride compacts. The techniques are finish turning, finish broaching, finish milling, and finish drilling.

Machining is a term that covers a large collection of manufacturing processes designed to remove unwanted material, usually in the form of chips, from a workpiece. This article discusses the basic classes of machining operations, including conventional, abrasive, and nontraditional, and outlines the type of costs incurred by the process. It describes the types of machining equipment, including general-purpose machine tools, production machining systems, and computer numerically controlled machining systems. The article lists the common classes of metallic work materials, in order of decreasing machinability. It also shows the range of dimensional and surface finish tolerances in graphical form that can be achieved using various machining processes under general machining conditions.