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.

Most welding lasers fall into the category of fiber, disc, or direct diode, all of which can be delivered by fiber optic. This article provides a comparison of the energy consumptions and efficiencies of laser beam welding (LBW) with other major welding processes. It discusses the two modes of laser welding: conduction-mode welding and deep-penetration mode welding. The article reviews the factors of process selection and procedure development for laser welding. The factors include power density, interaction time, laser beam power, laser beam diameter, laser beam spatial distribution, absorptivity, traverse speed, laser welding efficiency, and plasma suppression and shielding gas. The article concludes with a discussion on laser cutting, laser roll welding, and hybrid laser welding.

Current understanding of polishing wear involves a combination of abrasive, plastic flow, and tribochemical wear. This article explains these mechanisms and the correlation between them. Some explanations about practical polishing wear control, applications, and future prospects are also given. This article discusses the influence of size and number of wear particles on polishing at three abrasive wear modes. These include cutting, wedge forming, and plowing. The article concludes with information on applications and prospects of polishing wear control.

This article discusses the tribology of three main sheet forming processes: deep drawing, bending, and shearing. For each process, the basic principle of the forming process is briefly explained. Tribological phenomena observed in each process, such as wear and galling, are presented. Common methods of using lubricants and coatings in sheet forming processes are also described.

Metals and alloy powders are used in welding, hardfacing, brazing, and soldering applications, which include hardface coatings, the manufacturing of welding stick electrodes and flux-cored wires, and additives in brazing pastes or creams. This article reviews these applications and the specific powder properties and characteristics they require.

Thermal spray coating involves certain precoating operations, such as cleaning, surface preparation, and masking, that are critical to the overall quality of the coating system. In addition to these, certain other elements are considered prior to the coating, namely, customer requirements, coating function, part geometry, substrate metallurgy, structure, and thermal history. This article provides a detailed account of the various processes of surface preparation, namely, cleaning, roughening, dry abrasive grit blasting, and machining and macro roughening processes. It outlines the masking and fixturing techniques and stripping of coatings.

This article begins with a description of the advantages and disadvantages of thermal spraying. It provides a discussion on the importance of substrate processing prior to coating and the role of undercutting in repair. The article reviews the steps for substrate preparation, namely, cleaning, roughening, masking, and preheating. Information on the equipment and process variables of dry abrasive grit blasting are also provided. The article describes the roles of spray stream and the spray pattern for all thermal spray processes. It discusses the defects arising from poor temperature control and from the variables influencing the manipulation of the spray torch. The article concludes with helpful information on calculating the process efficiency of thermal spraying.

This article provides a history of electron and laser beam welding, discusses the properties of electrons and photons used for welding, and contrasts electron and laser beam welding. It presents a comparison of the electron and laser beam welding processes. The article also illustrates constant power density boundaries, showing the relationship between the focused beam diameter and the absorbed beam power for approximate regions of keyhole-mode welding, conduction-mode welding, cutting, and drilling.

This article presents an overview of the rules, regulations, and techniques implemented to minimize the safety hazards associated with welding, cutting, and allied processes. Safety management, protection of the work area, process-specific safety considerations, and robotic and electrical safety are discussed. The article explains the use of personal protective equipment and provides information on protection against fumes, gases, and electromagnetic radiation. It concludes with a discussion on safe handling of compressed gases as well as the prevention and protection of fire and explosion.

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 is a compilation of tables summarizing the fusion welding process. Included in the article is a table that presents the various fusion welding and cutting processes and their applications. Information on the general characteristics of arc welding processes is tabulated. The article also contains a list of the various criteria for selecting the suitable welding process for carbon steels.

This article discusses a set of experimental and computational studies aimed at understanding the effect of various processing parameters on the extent of burr and other defect formation during sheet edge-shearing and slitting processes. It describes the development of experimentally validated finite-element models for analyzing the classes of shearing processes. The article also discusses the use of microstructural characterization with stereology to render three-dimensional volumetric parameters. It concludes with information on the numerical simulation of an edge-shearing process, along with sensitivity studies with respect to process and tool parameters.

After solidification and cooling, further processing and finishing of the castings are required. This article describes the general operations of shakeout, grinding, cleaning, and inspection of castings, with particular emphasis on automation technology. It illustrates the vertical core knockout machine and the A-frame core knockout machine and lists the advantages and disadvantages of these machines. The article describes the general factors in automated or manual gate removal process. It concludes with discussion on the various types of inspection, such as the liquid penetrant inspection, pressure testing, radiographic inspection, magnetic particle inspection, and ultrasonic inspection.

This article provides an overview of the thixocasting process and discusses the concepts that are important to the practical application of this technology. The thixocasting process involves two casting processes. The first casting process is required to make the feedstock that must be reheated to achieve the structures necessary for casting. The second casting process combines billet sawing, reheating, and the actual injecting of material into the mold. The article focuses on these processes and provides information on rheological tests. It discusses some key design concepts used in thixocasting. The article illustrates the differences between a conventional high-pressure die-casting injection profile and the thixocasting injection profile used to produce the same part.

This article discusses the presses, auxiliary equipment, and dies used in the blanking and piercing of commonly used magnetically soft materials, namely, low-carbon electrical steels and oriented and nonoriented silicon electrical steels. It describes the effect of stock thickness and work metal composition and condition on blanking and piercing. The article provides an overview of the influence of burr height on stacking factors and presents a discussion on the lubrication and core plating of electrical steels that ease the process.

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.

This article illustrates the characteristics of pierced holes and summarizes the hole wall quality. Specific guidance in selecting die clearances is provided by considering the types of edges produced with different clearances. The article discusses the effect of tool dulling and the use of small and large clearance. It informs that the force needed to pierce a given material depends on the shear strength of the work metal, the peripheral size of the hole or holes to be pierced, stock thickness, and depth of shear on the punch. The article discusses the presses and tools used in piercing. It illustrates the use of compound dies, progressive dies, and transfer dies; piercing of thick and thin stock and piercing holes at an angle to the surface; special piercing techniques; and shaving of low-carbon steels.

This article reviews the general characteristics of copper and copper alloys and explains how these characteristics affect the behavior of strip in different types of forming operations. These forming operations include blanking, piercing, bending, drawing and stretch forming, spinning, rubber-pad forming, and contour roll forming. Specialized forming operations such as hydraulic forming, embossing and swaging, and high-velocity metal forming are also reviewed. The article discusses the forming of smaller and larger parts from copper and copper alloy strips, as well as their property requirements and applications.

Shearing is a method for cutting a material piece into smaller pieces using a shear knife to force the material past an opposition shear knife in a progression form. This article describes the principles, attributes, and defects of straight-knife shearing. The equipment, materials used, and the operating parameters are discussed. The article provides information on the applications of rotary shearing. It concludes with a discussion on devices equipped with shearing machines for protecting personnel from the hazards of shear knives, flywheels, gears, and other moving parts.