Search Results for multipoint cutting edges

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.

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.

This article discusses the classifications of high-speed tool steels and describes alloying elements and their effects on the properties of high-speed tool steels. It analyzes the heat treatment of high-speed tool steels, namely, preheating, austenitizing, quenching, and tempering. Surface treatments for the high-speed tool steels are reviewed. The article emphasizes the properties and applications of high-speed tool steels and provides information on the factors in selecting high-speed tool steels.

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.

Finite element analysis is a computer-based numerical method for solving engineering problems in bodies of user-defined geometry. This article introduces the important issues of finite elements (especially accuracy and efficiency) in a nonacademic manner. It describes the Rayleigh-Ritz procedure for solving structural problems based on the principle of virtual work. The article discusses continuum elements, such as hexahedra, pentahedra, tetrahedra, quadrilaterals, and triangles, commonly used in three- or two-dimensional domains. It considers structural elements such as beam element, plate element, shell element, and elbow element. The article presents three examples to illustrate the types of problems that can be addressed and the decisions that must be made when using finite element analysis.

Rapid prototyping (RP) techniques in the sheet-metal forming industry is developed to quickly test the form and fit of new sheet-metal products on a prototype basis as well as for production runs characterized by small lot sizes. This article provides an overview of some of the technologies used for RP and low-volume production of sheet-metal parts. It discusses low-cost tooling and flexible sheet-forming processes and reviews the various aspects of incremental sheet forming.

This article reviews the selection and formability characteristics of steels, with an emphasis on low-carbon steels and some coverage on the forming of high-carbon steels. It describes the key factors that affect the formability of steels in terms of steelmaking practices, surface finishes, metal thicknesses, and alloying. The article explains the bending and forming operations with some examples. It also describes the formation of various shells, including doubly contoured shells, deep recessed shells, and deep circular shells.

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.

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.

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.

This article illustrates the mechanics of the deep drawing of a cylindrical cup. It discusses the fundamentals of drawing and drawability. Sheet metal is drawn in either hydraulic or mechanical presses. The article summarizes the defects in drawing and factors considered in press selection for drawing. It explains the types of dies used for drawing sheet metal and the effects of process variables and material variables on deep drawing. The process variables that affect the success or failure of a deep-drawing operation include the punch and die radii, punch-to-die clearance, press speed, lubrication, and type of restraint of metal flow used. The article describes the process of redrawing and ironing of metals. Drawing of workpieces with flanges and drawing of hemispheres are also illustrated. The article also provides information on the reducing of drawn shells, methods for expanding portions of drawn workpieces, trimming, and deep drawing using fluid-forming presses.

This article is a compilation of definition of the terms related to thermal spray coating technology.

Several methods are developed for the numerical solution of partial differential equations, namely, meshed-solution methods such as the finite-element method (FEM), finite-difference method, and boundary-element method; and numerical algorithms consisting of so-called meshed-solution methods. This article introduces the methods of so-called meshed solutions, with an emphasis on the FEM. It presents some basic differential equations that are used to model the responses of structures, components, processes, or systems with emphasis on continuum mechanics. The article provides an outline on the mathematical principles of solving differential equations. It also reviews linear structural problems to illustrate the concept of the FEMs.

Passivation; pickling, that is, acid descaling; electropolishing; and mechanical cleaning are important surface treatments for the successful performance of stainless steel used for piping, pressure vessels, tanks, and machined parts in a wide variety of applications. This article provides an overview of the various types of stainless steels and describes the commonly used cleaning methods, namely, alkaline cleaning, emulsion cleaning, solvent cleaning, vapor degreasing, ultrasonic cleaning, and acid cleaning. Finishing operations of stainless steels, such as grinding, polishing, and buffing, are reviewed. The article also explains the procedures of electrocleaning, electropolishing, electroplating, painting, surface blackening, coloring, terne coatings, and thermal spraying. It includes useful information on the surface modification of stainless steels, namely, ion implantation and laser surface processing. Surface hardening techniques, namely, nitriding, carburizing, boriding, and flame hardening, performed to improve the resistance of stainless steel alloys are also reviewed.

This article discusses the classifications, compositions, properties, advantages, disadvantages, limitations, and applications of the most commonly used methods for surface engineering of carbon and alloy steels. These include cleaning methods, finishing methods, conversion coatings, hot-dip coating processes, electrogalvanizing, electroplating, metal cladding, organic coatings, zinc-rich coatings, porcelain enameling, thermal spraying, hardfacing, vapor-deposited coatings, surface modification, and surface hardening via heat treatment.

Bearings are usually provided where a specific spatial relationship (alignment) must be maintained between the parts or where a force is to be transmitted from one part to the other. This article introduces the general types and configuration of sliding bearings, bearing materials, and the practical aspects and solutions in the friction, lubrication, and wear mitigation of sliding bearings. The lubrication of bearings includes thick-film lubrication, thin-film lubrication, and boundary lubrication. The article concludes with a discussion on the effects of material elasticity on the lubrication of bearings.

The design process for ceramic materials is more complex than that of metals because of low-strain tolerance, low fracture toughness and brittleness. The application of structural ceramics to engineering systems hinges on the functional benefits to be derived and is manifested in the conceptual design for acceptable reliability. This article discusses the design considerations for the use of structural ceramics for engineering applications. It describes the conceptual design and deals with fast fracture reliability, lifetime reliability, joints, attachments, interfaces, and thermal shock in detailed design procedure. The article provides information on the proof testing of ceramics, and presents a short note on public domain software that helps determine the reliability of a loaded ceramic component. The article concludes with several design scenarios for gas turbine components, turbine wheels, ceramic valves, and sliding parts.

Impact tests are used to study dynamic deformation and failure modes of materials. This article discusses low-velocity impact experiments in single-stage gas guns. It describes surface velocity measurements with laser interferometric techniques. The article details plate impact soft-recovery experiments, pressure-shear friction experiments, and low-velocity penetration experiments. It reviews two types of plate impact soft-recovery experiments: normal plate impact and pressure-shear plate impact experiments. The article provides information on low-velocity penetration experiments, which include the setup for direct penetration experiment (rod-on-plate) and the reverse penetration experiment (plate-on-rod). It also considers high-temperature plate impact testing and impact techniques with in-material stress and velocity measurements.