Search Results for cutting

Laser has found its applications in cutting, drilling, and shock-peening operations of manufacturing industry because of its accurate, safe, and rapid cutting property. This article provides an account on the fundamental principles of laser cutting (thermal), drilling, and shock-peening processes of which emphasis is placed on thermal laser cutting. It details the principal set-up parameters, such as the laser beam output, nozzle design, focusing optic position and characteristics, assist gases, surface conditions, and cutting speed. A discussion on the types of gas, supply system, purity level, and flow rates of lasing and assist gases is also provided. The article also describes the metallurgies and other key material considerations that impact laser-cutting performances and includes examples of laser cutting of nonmetal materials.

This article focuses on the mechanical and nonmechanical cutting methods used in metal fabrication industries. The most prevalent equipment used for mechanical cutting includes shears, iron workers, nibblers, and band saws. Nonmechanical methods of cutting include gas cutting, electric arc cutting, and laser cutting. The article concludes with information on the advantages of abrasive waterjet cutting, which is an alternative to laser cutting, gas cutting, and plasma cutting.

Oxyfuel gas cutting (OFC) includes a group of cutting processes that use controlled chemical reactions to remove preheated metal by rapid oxidation in a stream of pure oxygen. This article discusses the operation principles and process capabilities of the OFC. It reviews the properties and compositions of fuel types such as acetylene, natural gas, propane, propylene, and methyl-acetylene-propadiene-stabilized gas. The article describes the effects of OFC on base metal, including carbon and low-alloy steels, cast irons, and stainless steels. It provides information on light cutting, medium cutting, heavy cutting, and stack cutting. The article informs that the basic oxyfuel method can be modified to allow gas cutting of metals, such as stainless steel and most nonferrous alloys, that resist continuous oxidation.

Electric arc cutting is used on ferrous and nonferrous metals for rough severing, such as removing risers or scrap cutting, as well as for more closely controlled operations. This article describes the operating principles, equipment selection, process variables, and safety measures recommended for plasma arc cutting and air carbon arc cutting. Special applications of electric arc cutting, including shape cutting, gouging, and underwater cutting, are also discussed. The article provides information on other electric arc cutting methods, namely, the exo-process and oxygen arc cutting. It concludes with information on the seldom-used electric arc cutting methods, such as shielded metal arc cutting, gas metal arc cutting, and gas tungsten arc cutting.

Cutting with lasers is accomplished with carbon dioxide (CO 2 ) and neodymium: yttrium-aluminum-garnet (Nd:YAG) lasers. This article provides a description of the process variables and principles of laser cutting. It discusses the three basic types of CO 2 gas lasers, namely, slow axial flow, transverse flow, and fast axial flow and reviews the applications of Nd:YAG laser. The article describes the basic parameters in the laser-cutting process: beam quality, power, travel speed, nozzles design, and focal-point position. Several material conditions that affect the quality of the laser cut are also discussed. The article provides information on the basic laser-cutting system and its optional equipment. A general description of how well each metal group can be cut is also provided.

This article provides a detailed account of the process development, cutting principle, and components of the abrasive waterjet cutting process. The advantages of abrasive waterjet machining are summarized. The article also discusses the factors affecting the cut quality, and the applications and limitations of abrasive waterjet cutting.

This article reviews the history of prepreg and ply cutting technologies and outlines the options available for creating the necessary data and for nesting, cutting, and kitting the plies. It discusses the ways in which these steps influence the workflow for various applications. The characteristics of prepreg and ply cutting methods are presented in a table.

This article discusses the operating principles, types, and applications of shearing and slitting of different forms of steel, including plates, flat sheets, bars, coiled sheet and strips. In addition, it provides a detailed account of the cutting methods such as oxyfuel gas cutting, plasma arc cutting, oxygen arc cutting, laser beam cutting, and air carbon arc cutting and gouging, describing their process capabilities, equipment used, operating principles and parameters, and factors affecting their efficiency.

This article describes the use of conventional machining techniques, laser cutting and water-jet cutting for producing finished composite parts. It explains two representative polymer-matrix composites--graphite and aramid composites--and discusses the machining and drilling problems such as delamination and fiber or resin pullout. The article describes machining and drilling techniques and the necessary tools and cutting parameters. It presents a description of laser cutting. The article also provides information on the advantages, disadvantages, cutting characteristics, and applications of water-jet cutting and abrasive water-jet cutting.

Plasma arc cutting (PAC) is an erosion process that utilizes a constricted arc in the form of a high-velocity jet of ionized gas to melt and sever metal in a narrow, localized area. This article discusses the process description, equipment, gases, operating sequence, process considerations, and applications of PAC. It concludes with a discussion on the safety measures associated with the PAC process.

This article describes the principles of operation, operating techniques, equipment selection, and important process variables of air-carbon arc cutting. It also provides information on the safety practices to be followed during the air-carbon arc cutting process.

Mechanical cutting methods are widely used by the metal fabrication industry. This article introduces the welding fabricator to some of the mechanical equipment used to shape or prepare metals for welding. The most prevalent equipment used for mechanical cutting includes shears, iron workers, nibblers, and band saws. The article provides details on each of these.

Oxyfuel gas cutting (OFC) includes a group of cutting processes that use controlled chemical reactions to remove preheated metal by rapid oxidation in a stream of pure oxygen. This article provides a detailed discussion on the principles of operation and the process capabilities of OFC. In addition to providing information on the equipment used, the article describes the properties of fuel gases (acetylene, natural gas). It also presents an overview of the effect of OFC on base metal and explains the application of OFC in cutting thin, medium, and thick sections, bars, and structural and close-tolerance shapes.

This article discusses the functions and chemistry of metal cutting or grinding fluids. It reviews the choice of cutting or grinding fluids that is influenced by the workpiece material, fluid characteristics, and machining operation. The article describes two application methods of cutting or grinding fluids: flooding and misting. It discusses and lists the American Society for Testing and Materials standard test procedures used in establishing control of cutting and grinding fluids. The article provides information on the storage, distribution, cleaning, and disposal of cutting and grinding fluids. It concludes with information on the health implications and biology of cutting fluids.

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.

The classes of tool materials for machining operations are high-speed tool steels, carbides, cermets, ceramics, polycrystalline cubic boron nitrides, and polycrystalline diamonds. This article discusses the expanding role of surface engineering in increasing the manufacturing productivity of carbide, cermet, and ceramic cutting tool materials used in machining operations. The useful life of cutting tools may be limited by a variety of wear processes, such as crater wear, flank wear or abrasive wear, builtup edge, depth-of-cut notching, and thermal cracks. The article provides information on the applicable methods for surface engineering of cutting tools, namely, chemical vapor deposited (CVD) coatings, physical vapor deposited coatings, plasma-assisted CVD coatings, diamond coatings, and ion implantation.

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.

Selecting the proper cutting tool material for a specific machining application can provide substantial advantages, including increased productivity, improved quality, and reduced costs. This article begins with a description of the factors affecting the selection of a cutting tool material. This is followed by a schematic representation of their relative application ranges in terms of machining speeds and feed rates. The article provides a detailed account of chemical compositions of various tool materials, including high-speed tool steels, cobalt-base alloys, cemented carbides, cermets, ceramics, cubic boron nitride, and polycrystalline diamond. It compares the toughness, and wear resistance for these cutting tool materials. Finally, the article explains the steps for selecting tool material grades for specific application.

Cutting fluids play a major role in increasing productivity and reducing costs by making possible the use of higher cutting speeds, higher feed rates, and greater depths of cut. After listing the functions of cutting fluids, this article then covers the major types, characteristics, advantages and limitations of cutting and grinding fluids, such as cutting oils, water-miscible fluids, gaseous fluids, pastes, and solid lubricants along with their subtypes. It discusses the factors considered during the selection of cutting fluid, focusing on machinability (or grindability) of the material, compatibility (metallurgical, chemical, and human), and acceptability (fluid properties, reliability, and stability). The article also describes various application methods of cutting fluids and precautions that should be observed by the operator.