Heat treating furnaces require different control systems and integration for achieving optimum technical results and enabling safe operation. This article focuses on atmosphere furnaces, with some coverage on controls for vacuum furnaces. Heat treating operations require reliable monitoring and control of motion and position of various mechanical components with the help of mechanical limit switches, proximity sensors, and distance- and position-measuring devices. Using inputs from both flow meters and sensors, such as thermocouples and oxygen sensors, flow measurement control systems must be able to adjust the flow of gases for process optimization. The operator interface of a furnace-control system displays critical information such as the furnace temperature, atmosphere status, alarms, electronic chart recorders, recipe, and maintenance. A supervisory control and data-acquisition (SCADA) system is used to monitor, collect, and store data from multiple pieces of equipment.

Electron beam welding (EBW) can produce deep, narrow, and almost parallel-sided welds with low total heat input and relatively narrow heat-affected zones in a wide variety of common and exotic metals. This article focuses on essential parameters of EBW, namely, weld and surface geometry, part configuration, melt-zone configuration, weld atmosphere (vacuum and nonvacuum), and joint design. It describes various aspects considered in EBW of thin and thick metal sections and poorly accessible joints. An overview of scanning and joint tracking techniques for inspection of electron beam-welded joints is also included. The article concludes with discussions on EBW defects, the use of filler metal for weld repair, and the control plans, codes, and specifications of the EBW process.

Autoclave molding is a process used to impart a controlled heat and pressure cycle cure to a layup. This article describes the materials used for preparing a layup, including peel ply, separator, bleeder, barrier, breather, dam, and vacuum bag. It describes the major elements and functions of an autoclave system, including pressure vessel, gas stream heating and circulation sources, gas stream pressurizing systems, vacuum systems, control systems, and loading systems. The article includes information about modified autoclaves for specialized applications and safety practices in autoclave molding. It also describes the tooling configuration and type of tooling which includes aluminum and steel tooling, electroformed nickel tooling, graphite-epoxy tooling, and elastomeric tooling.

Forging of nickel-base alloys results in geometries that reduce the amount of machining to obtain final component shapes and involves deformation processing to refine the grain structure of components or mill products. This article discusses the heating practice, die materials, and lubricants used in nickel-base alloys forging. It describes two major forging processing categories for nickel-base alloys: primary working and secondary working categories. Primary working involves the deformation processing and conversion of cast ingot or similar bulk material into a controlled microstructure mill product, such as billets or bars, and secondary working refers to further forging of mill product into final component configurations.

This article commences with a schematic illustration of a wide range of cutter configurations available for use in milling operations. It describes the various types of milling machines classified based on the type of construction, such as knee-and-column type, bed-type, planer-type, and special type. The article discusses mechanical-electric, mechanical-hydraulic, mechanical-electric-hydraulic, and numerical control of milling machines. It describes various types of milling cutters, such as peripheral mills, face mills, end mills, and special mills. Milling cutters, such as solid milling cutters, inserted-blade cutters, and indexable-insert cutters, are also discussed. The article explains the capabilities and limitations of peripheral milling, face milling, and end milling methods. It concludes with a comparison of milling with broaching, planing or shaping, and grinding.

Turning is a machining process for generating external surfaces of revolution by the action of a cutting tool on a rotating workpiece, usually in a lathe. This article discusses the process capabilities of turning over other machining operations and describes the classification, controlling methods, attachments, and accessories of a lathe machine. It reviews the design and various operations of single-point cutting tools in turning. In addition, the article discusses the influence of various factors on selection of equipment and machining procedure for a specific part. These include the size and configuration of the workpiece, equipment capacity, production quantity, dimensional accuracy, number of operations, and the surface finish. It presents examples that describe or compare equipment and techniques for production applications. Finally, the article provides a discussion on the classification and compatibility of cutting fluids.

Boring is a machining process in which internal diameters are generated in true relation to the centerline of the spindle by means of single-point cutting tools. This article provides a discussion on boring machines and boring tools and presents a comprehensive discussion on the various elements of boring. The elements are composition and hardness of workpiece metal, cutting fluid, speeds and feeds, and methods for piloting and supporting tools in boring applications. The article explains the role of workpiece size in selecting the equipment and processing procedure and the use of techniques to overcome difficulties presented by workpiece configuration. It describes the factors related to accuracy of boring and factors affecting them. The article also presents a discussion on close-tolerance boring and methods of controlling vibration and chatter. It concludes with a section presenting information on the use of boring equipment for machining operations other than boring.

Shaping and slotting are used to remove metal from surfaces through the use of a single-point tool supported by a ram that reciprocates the tool in a linear motion against the workpiece. This article discusses the process capabilities of shaping and slotting with respect to the size and configuration of the workpiece. Shaping and slotting machines develop cutting action from a straight-line reciprocating motion between the tool and the workpiece. The article describes the types of shapers such as horizontal shaper and vertical shaper. It briefly discusses the applications of high-speed steel tools and carbide tools for shaping. The article also illustrates the dimensional control of workpieces during shaping. It concludes with a discussion on gear shaping.

This article describes the melting process of casting metals used in hot chamber die casting. It discusses the design and capabilities of injection components, such as gooseneck, plunger, and cylinder. The article reviews the distinctions between hot and cold chamber processes. An example of a typical runner, gate and overflow configuration for faucet fixture casting is shown. Temperature control for die casting is also discussed. The article explains some ejection and post-processing techniques used for the hot chamber die casting: robotics, recycling, and fluxing.

This article describes the process applications, advantages, and limitations of resistance seam welding. The fundamentals of lap seam welding are also reviewed. The article details the types of seam welds, namely, lap seam welds and mash seam welds, and the processing equipment used for lap seam welding. The primary factors used to determine the selection of electrodes, including alloy type and wheel configuration, are reviewed. The article also describes weld quality and process control procedures.

Thermal phenomena play a key role in the mechanics of surface finishing processes. This article provides information on the analysis and measurement of temperatures and associated thermal damage generated by finishing processes that are essential to the production of engineered components with controlled surface properties. Emphasis is placed on kinematically simple configurations of finishing processes, such as surface grinding, flat surface polishing, and lapping.

This article describes the test methods for evaluating the durability of a metal in soil. It provides useful information on soil characteristics such as soil electrical resistivity, pH value, and soil texture. Specimen design, preparation, burial, and retrieval techniques are discussed. The type of information sought during soil-induced corrosion evaluation controls the design configuration and the nature of the corrosion measurements. Consideration of these factors during the planning stage helps the corrosion engineer to obtain the maximum amount of information with the minimum number of problems.

This article provides an overview of the fundamentals of tribology. It describes the advantages, disadvantages, and applications of the pin-on-disk method, which is the most commonly used configuration for testing biomaterials and for the reproducible measurement of friction and wear. The article illustrates a practical tribocorrosion setup that allows a user to perform wear tests in corrosive environments under well-defined electrochemical conditions and at controlled temperature. It explains the effect of changes in electrical contact resistance on tribological mode. The article discusses various in vivo environmental conditions in tribological tests. Some typical examples of biomaterials testing are also provided.

Elastomeric tooling uses rubber details to generate required molding pressure or to serve as a pressure intensifier during composite part curing cycles. This article discusses the various aspects of the forms of commercially available bag-side elastomeric caul systems. It describes the two basic methods, such as the trapped or fixed-volume rubber method and the variable-volume rubber method, of elastomeric tooling, which use the principles of thermal expansion molding. The significant properties and controlling equations that are required to characterize elastomeric tooling material are also discussed.

This article discusses the conceptual and configuration design of special-purpose parts that are designed and manufactured especially for use in a particular application. It provides a discussion on the issues considered in designing of parts, including, functionality; the relationship of the part to the whole assembly or subassembly; material and process selection; configuration; and tolerances. The article discusses the qualitative physical reasoning and qualitative reasoning that assist in developing part configuration alternatives.

Tooling and assembly methodologies for advanced composites have steadily improved as a result of advancements in materials, through the use of computer-aided design/computer-aided manufacturing technology, and through application of sophisticated design for manufacturing and assembly concepts. This article reviews techniques and technologies that are used to control the quality of tooling and assembly methods for composite components.

The process of transferring coating materials from the container to the surface to be coated can be accomplished in a number of ways. This article describes seven methods of coating application: brushes, rollers, and daubers; conventional air spray; high-volume low-pressure spray; airless spray; air-assisted airless spray; plural-component spray; and electrostatic spray. Factors to be considered when deciding on an application method include the size and configuration of the surfaces to be coated, the type of coating being applied, environmental regulations/restrictions, the proximity to other operations or personnel, and the recommendations of the coating manufacturer.

This article presents an overview of an engineering design process. Though the process is extremely complex, distinct stages of design activities are identified and described. The article illustrates guided iteration methodology that helps in problem solving in design. It describes the engineering conceptual design and configuration design of special-purpose parts. It discusses the parametric design methods of the parts and best practices that are used by successful firms to achieve the goals of quality, cost, time-to-market, and marketing flexibility.