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.

Ceramic coatings are applied to metals to protect them against oxidation and corrosion at room temperature and at elevated temperatures. This article provides a detailed account of the factors to be considered when selecting a ceramic coating and describes the characteristics of various coating materials, namely, silicate glasses, oxides, carbides, silicides, and cermets. It reviews ceramic coating methods: brushing, spraying, dipping, flow coating, combustion flame spraying, plasma-arc flame spraying, detonation gun spraying, pack cementation, fluidized-bed deposition, vapor streaming, troweling, and electrophoresis. The article also includes information on the evaluation of the quality of ceramic coatings.

Shot peening is a method of cold working in which compressive stresses are induced in the exposed surface layers of metallic parts by the impingement of a stream of shot, directed at the metal surface at high velocity under controlled conditions. This article focuses on the major variables, applications, and limitations of shot peening and provides information on peening action, surface coverage, and peening intensity. It discusses the equipment used for shot recycling and shot propelling as well as the types and sizes of media used for peening. The article describes the problems in shot peening of production parts. It concludes with information on the SAE standard J442 that describes the test strips, strip holder, and gage used in measuring shot peening intensity.

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.

This article introduces filling and feeding concepts from the general perspective of what constitutes good casting practice. It briefly reviews concepts that may help clarify and quantify objectives for more effective mold-filling designs. The article describes the preprimed filling system through various partial solutions to the prepriming approach. The naturally pressurized filling system is characterized by the narrowness of its flow channels. The article discusses the six individual parts of the naturally pressurized filling system, namely, offset stepped pouring basin, sprue, sprue/runner junction, runner, gates, and feeding via feeders. It also lists key features of the naturally pressurized filling system.

Batch furnaces and continuous furnaces are commonly used in heat treating. This article provides a detailed account of various heat treating equipment and its furnace types, including salt bath equipment (externally heated, immersed-electrode and submerged-electrode furnaces), and fluidized-bed equipment (external-resistance-heated fluidized beds). It describes various auxiliary equipment used in cold-wall furnaces, namely, heating elements and pumping systems. Five types of heat-resistant alloys are used for furnace parts, trays, and fixtures: Fe-Cr alloys, Fe-Cr-Ni alloys, Fe-Ni-Cr alloys, nickel-base alloys and cobalt-base alloys. The article lists the recommended applications for alloys for parts and fixtures for various types of heat treating furnaces.

Gas analysis by mass spectrometry, or gas mass spectrometry, is a general technique using a family of instrumentation that creates a charged ion from a gas phase chemical species and measures the mass-to-charge ratio. This article covers gas analysis applications that do not use chromatographic separation to physically isolate components of the sample prior to analysis. It is intended to provide an understanding of gas analysis instrumentation and terminology that will help make informed decisions in choosing an instrument and methodology appropriate for the data needed. Mass-analyzer technologies for gas mass spectrometry, namely quadrupole mass filters, magnetic sector mass filters, and time-of-flight mass analyzers are covered. Common factors to consider in choosing an analyzer for static or continuous gas measurement are also described. In addition, the article presents some examples of applications of gas mass spectrometry.

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.

Vacuum heat treating consists of thermally treating metals and alloys in cylindrical steel chambers that have been pumped down to less than normal atmospheric pressure. This article provides a detailed account of the operations and designs of vacuum furnaces, discussing their pressure levels, resistance heating elements, quenching systems, work load support, pumping systems, and temperature control systems. It describes the classification of instruments used for measuring and recording pressure inside a vacuum processing chamber. Common devices include hydrostatic measuring devices and devices for measuring thermal and electrical conductivity. The article also describes the applications of the vacuum heat treating process, namely, vacuum nitriding and vacuum carburizing. Finally, it reviews the heat treating process of tool steels, stainless steels, Inconel 718, and titanium and its alloys.

Wear is mechanically-induced surface damage that results in the progressive removal of material. Because different types of wear occur in machinery, many different types of wear tests have been developed to evaluate its effects on materials and surface treatments. This article provides an explanation on mechanisms, forms (sliding, impact, and rolling) and the causes of wear. It describes the wear measuring methods, including the mass loss method, wear width method, and scar depth method. The units used to report wear vary with type of wear and with the purpose for which the data are to be used. Listing the considerations of tribosystem analysis, the article provides information on selection of ASTM wear test methods grouped by wear type. The article concludes by tabulating the testing geometries and parameters that are commonly controlled and reported when conducting wear tests.

In high-iron-tonnage operations, the cupola remains the most efficient source of continuous high volumes of iron needed to satisfy high production foundries or the multiple casting machines of centrifugal pipe producers. This article explores successful improvement technologies in cupola equipment, including preheated air blast, recuperative hot blast systems, and duplex electric holders. It discusses the shell, intermittent or continuous tapping, tuyere and blower systems, refractory lining, water-cooled cupolas, emission-control systems, and storage and handling of the charge materials. The article provides a discussion on control tests for cupola, including the chill test and mechanical test. It concludes with information on specialized cupolas such as cokeless cupola and plasma-fired cupola.

This article illustrates the basic components of dry and wet hearth reverberatory furnace. It discusses stack melters that are used for aluminum metal casting, as they are efficient in sealing the furnace and using the flue gases to preheat the charge materials. The article describes the various factors for improving and maintaining furnace efficiencies. It explains the benefits of circulating molten metal in reverberatory furnaces and circulation methods.

This article uses metal and alloy powders as examples to briefly discuss how to perform the characterization of powders. It begins by reviewing some of the techniques involved in the sampling of powders to ensure accurate characterization. This is followed by a discussion on the important properties to characterize powders, namely the particle size, surface area, density, porosity, particle hardness, compressibility, green strength, and flowability. For characterization of powders, both individual particles and bulk powders are used to evaluate their physical and chemical properties. The article also discusses the important characteristics and compositions of powder as well as impurities that directly affect powder properties. It ends with a description of the ignition and dust-explosion characteristics of organic and metal powders.

Mechanical cleaning systems are used to remove contaminants of work surface by propelling abrasive materials through any of these three principal methods: airless centrifugal blast blade- or vane-type wheels; compressed air, direct-pressure dry blast nozzle systems; or compressed-air, indirect-suction (induction) wet or dry blast nozzle systems. This article focuses on the abrasive media, equipment, applications, and limitations of dry and wet blast cleaning. It discusses the health and safety precautions to be taken during mechanical cleaning.

This article provides a discussion on ten rules for the effective production of reliable castings. The rules include good-quality melt, liquid front damage, liquid front stop, bubble damage, core blows, shrinkage damage, convection damage, segregation, residual stress, and location points.

This article discusses the techniques and applications of synchrotron x-ray diffraction, providing information on x-ray generation, monochromation, and crystallography. X-ray diffraction techniques covered include single-crystal and powder diffraction. Some of the factors involved in the construction and development of macromolecular x-ray crystallography are also described.

This article discusses the most common methods of melting steels, namely, electric arc and induction melting. It describes the classification of refractories by an index of the “basicity” of the slag formed on the steel surface. The steel melt refinements are classified as treatments by either converter metallurgy or ladle metallurgy. The article provides a detailed discussion on the converter and ladle metallurgy. The converter metallurgy includes melt refinement in argon oxygen decarburization (AOD) vessels and vacuum oxygen decarburization (VODC) in a converter vessel. The ladle metallurgy includes vacuum induction degassing, vacuum oxygen decarburization, and vacuum ladle degassing.

This article briefly describes the capabilities of gas chromatography/mass spectrometry, which is used to qualitatively and quantitatively determine organic (and some inorganic) compound purity and stability and to identify components in a mixture. The discussion covers in more detail gas chromatography/mass spectrometry (GC/MS) instrumentation, interpreting mass spectra, GC/MS methodology, and GC/MS advances. Sample preparation, which is very important in GC/MS to avoid erroneous data and to minimize maintenance and troubleshooting of the instrument, is also discussed. Further, the article highlights the state of the art in the MS detector technology.

This article presents a detailed account on the process flow, composition, alternative sources, and the advancement of ironmaking, steelmaking and secondary steelmaking practices. Some steels, such as bearing steels, heat-resistant steels, ultrahigh strength missile and aircraft steels, and rotor steels have higher quality requirements and tighter composition control than plain carbon or ordinary low-alloy steels. The production of special-quality steels requires vacuum-based induction or electric remelting and refining capabilities. The article explores the types and characteristics of various steel manufacturing processes, such as ingot casting, continuous casting, and hot rolling. It provides an outline of specialized processing routes of producing ultralow plain carbon steels, interstitial-free steels, high strength low-alloy steels, ultrahigh strength steels, stainless steels, and cold-rolled products, and briefly explains the analytical techniques for liquid steels.