This article discusses the various categories of nontraditional machining processes that are subdivided according to the form of energy being harnessed. These include mechanical, electrical, thermal, and chemical methods.

This article is a comprehensive collection of summary charts that provide data and information that are helpful in considering and selecting applicable processes alternative to the conventional material-removal processes. Process summary charts are provided for electrochemical machining, electrical discharge machining, chemical machining, abrasive jet machining, laser beam machining, electron beam machining, ultrasonic impact grinding, hydrodynamic machining, thermochemical machining, abrasive flow machining, and electrical discharge wire cutting.

The machinability of stainless steels varies from low to very high, depending on the final choice of the alloy. This article discusses general material and machining characteristics of stainless steel. It briefly describes the classes of stainless steel, such as ferritic, martensitic, austenitic, duplex, and precipitation-hardenable alloys. The article examines the role of additives, such as sulfur, selenium, tellurium, lead, bismuth, and certain oxides, in improving machining performance. It provides ways to minimize difficulties involved in the traditional machining of stainless steels. The article describes turning, drilling, tapping, milling, broaching, reaming, and grinding operations on stainless steel. It concludes with information on some of the nontraditional machining techniques, including abrasive jet machining, abrasive waterjet machining electrochemical machining, electron beam machining, and plasma arc machining.

Nickel-base alloys can be machined by techniques that are used for iron-base alloys. This article discusses the effects of distortion and microstructure on the machinability of nickel alloys. It tabulates the classification of nickel alloys based on machining characteristics. The article describes the machining operations performed on nickel alloys, such as turning, planing and shaping, broaching, reaming, drilling, tapping and threading, milling, sawing, and grinding. It provides information on the cutting fluids used in the machining of nickel alloys. The article also analyzes nontraditional machining methods that are suitable for shaping high-temperature, high-strength nickel alloys. These include electrochemical machining, electron beam machining, and laser beam machining.

The horsepower requirements to cut various metal alloys provide an indication of the relative ease and cost of machining, but several other important factors include cutting tool material, chip formation, cutting fluids, cutting tool wear, surface roughness, and surface integrity. This article reviews these general machining factors as well as specific cutting tool and cutting parameters for the six basic chip-forming processes of turning, shaping, milling, drilling, sawing, and broaching. Best practices for each of the six chip-forming processes are suggested for optimized machining of aluminum alloys. The article lists the inherent disadvantages of machining processes that involve compression/shear chip formation. It discusses the machining of aluminum metal-matrix composites and nontraditional machining of aluminum, such as abrasive jet, waterjet, electrodischarge, plasma arc, electrochemical, and chemical machining.

This article distinguishes between a surface finish and a surface texture. It provides information on the surface integrity technology that describes and controls the many possible alterations produced in a surface layer during manufacture, including their effects on material properties and the performance of the surface in service. The types of surface alterations associated with metal removal practices are described. The article discusses the surface roughness, surface integrity, and produced in manufacturing processes, and mechanical property effects. Surface alterations associated with metal removal practices of traditional and nontraditional machining operations, as well as their effect on the static mechanical properties of materials, are reviewed. Finally, the article provides guidelines for material removal, postprocessing, and inspection.

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.

This article provides an overview of the independent and dependent variables of a machining process. Independent variables include workpiece material, specific machining processes, and tool materials and geometry. Cutting force and power, surface finish, and tool wear and failure are some dependent variables discussed. The article also describes the relations between the input variables and process behavior.

Abrasive flow machining (AFM) finishes surfaces and edges by extruding viscous abrasive media through or across the workpiece. This article commences with a schematic illustration of the AFM process that uses two opposed cylinders to extrude semisolid abrasive media back and forth through the passages formed by the workpiece and tooling. It discusses the major elements of an AFM system, such as machine, tooling, and abrasive media. The article provides information on polishing, radiusing, edge finishing, and surface finishing capabilities of the AFM. It concludes with information on the various applications of the AFM process.

This article describes the influence of steel chemical compositions and microstructure on machining processes. It discusses the various microstructural phases of standard carbon and alloy steels, which influence machinability. The article reviews the expected response of several traditional machining operations, such as turning, drilling, milling, shaping, thread cutting, and grinding, to the microstructure of standard steel grades. It also explains the technologies in non-traditional machining processes, such as abrasive waterjet cutting, electrical chemical grinding, and laser drilling.

This article presents general guidelines for machining metal matrix composites (MMC) and honeycomb structures. It provides guidelines for machining of specific MMCs, namely, aluminum-boron, aluminum-SiC, aluminum-Al 2 O 3 , and titanium-SiC MMCs. In addition, the article discusses the various parameters influencing drilling of dissimilar-material laminates.

This article reviews the methods of machining and finishing forging dies. It illustrates different stages in die manufacturing. The article provides a brief description on requirements and characteristics of high-speed machining tools, including feed rates, spindle speed, surface cutting speeds, and high acceleration and deceleration capabilities. It discusses electrodischarge machining process and electrochemical machining process. The article concludes with information on die-making methods.

Nontraditional finishing processes include electrochemical machining (ECM), electrodischarge machining (EDM), and laser beam machining. These processes belong to nonabrasive finishing methods where surface generation occurs with an insignificant amount of mechanical interaction between the processing tool and the workpiece surfaces. This article provides information on the equipment used, applications, process capabilities, and limitations of ECM and EDM.

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.

Machining or material removal processes are secondary manufacturing operations that are used to achieve precise tolerances or to impart controlled surface finishes to a part. This article summarizes rules for designing parts to improve machined part quality and reduce machining costs in mass and batch production environments. It discusses the factors affecting the total cost of a machining operation, including raw material costs, labor costs, and equipment costs. The article describes three types of machining systems, namely, general-purpose machine tools, production machining systems, and computer numerically controlled (CNC) machining systems. It reviews general design-for-machining rules that are applicable to all parts, regardless of the type of equipment used to produce them. Special considerations for production machining systems and CNC machining systems are discussed. The article describes the structure and typical uses of computer-aided process planning and design-for-manufacturing programs.

Both surface finish and surface integrity must be defined, measured, and maintained within specified limits in the processing of any product. Surface texture is defined in terms of roughness, waviness, lay, and flaws. This article illustrates some of the designations of surface roughness and the symbols for defining lay and its direction. In addition, it describes the applications of surface integrity, typical surface integrity problems created in metal removal operations, and principal causes of surface alterations produced by machining processes. The article tabulates the effect of some machining methods on fatigue strength, and low-stress grinding procedures for steels, nickel-base high-temperature alloys, and titanium alloys.

Finishing refers to a wide variety of processes that generally involve material removal in one form or another to generate surfaces with specific geometries, tolerances, and functional or decorative characteristics. This article discusses four major finishing methods, namely, abrasive machining, electropolishing, mass finishing, and shot peening. In each case, it describes subtypes, process variations, and the associated equipment.

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 focuses on a variety of laser beam machining (LBM) operations of aluminum and its alloys, namely, laser cutting, laser drilling, laser milling, laser turning, laser grooving, laser scribing, laser marking, and laser micromachining. It presents different approaches for carrying out machining operations, laser processing parameters, efficiency and accuracy of the process, and the effect of laser processing parameters on the quality of the machined surface. The article provides an overview of the various conventional (chip forming) and nonconventional machining techniques employed for aluminum-based materials. A comparison of the various aspects of LBM with other non-conventional techniques is also presented. The article also describes the features of LBM techniques employed for aluminum and its alloys for different types of machining.

This article focuses on the machining of reactive metals which refer collectively to the elements titanium, hafnium, and zirconium. It provides guidelines for machining titanium and titanium alloys and describes machining operations, such as turning, milling, drilling, tapping, reaming, grinding, and sawing, performed on titanium and its alloys. The article also provides information on electrochemical machining (ECM), chemical milling (CHM), and laser beam machining (LBM) for titanium and titanium alloys. Guidelines for machining zirconium alloys and hafnium are also provided. The article provides a short description of turning, milling, and drilling operations performed on zirconium alloys and hafnium. It also discusses health and safety considerations related to zirconium and hafnium.