This article describes the types of fabrics and preforms used in the manufacture of advanced composites and related selection, design, manufacturing, and performance considerations. The types of fabrics and preforms include unidirectional and two-directional fabrics; multidirectionally reinforced fabrics; hybrid fabrics; woven fabric prepregs; unidirectional and multidirectional tape prepregs; and the prepreg tow. The article discusses three major categories of tape manufacturing processes, namely, the hand lay-up, machine-cut patterns that are laid up by hand, and the automatic machine lay-up. It provides a description of the two classes of prepregs. These include those that are suitable for high-performance applications and suitable for lower-performance molding compounds.

High-temperature-resistant polymers are used in aerospace, electronic, and other applications that demand outstanding elevated-temperature physical and mechanical properties. This article discusses the general characteristics of condensation-type polyimides and polymerization of monomer reactants (PMR) polyimides. It provides information on the applications of PMR-15 with illustrations.

Additive manufacturing (AM) has been adopted as one of the most versatile and rapid design-to-manufacturing approaches for printing a wide range of two- and three-dimensional parts, devices, and complex geometries layer by layer. This article provides insights into the current progress, challenges, and future needs of AM of electronics from the space, defense, biomedical, energy, and industry perspectives.

This article addresses the types, properties, forms, and applications of fibers that are available for use in fiber-reinforced polymeric matrix composites, including glass, graphite, carbon, aramid, boron, silicon carbide, ceramic, continuous oxide and discontinuous oxide fibers. It describes the functions, types, and chemical composition of fiber sizing agents. The article discusses the styles, properties, applications, and weaving methods of unidirectional, two-directional and multidirectionally reinforced fabrics. The article also reviews the use of prepreg resins in aerospace and lower performance applications.

This article discusses the historical background of composite construction in recreational equipment and sporting goods. It provides information on the applications of composites in baseball bats, tennis rackets, and golf clubs. The applications of composites in bicycling, winter sports, aquatic sports, track, field, and archery equipment are also discussed.

This article reviews the abrasive and adhesive wear failure of several types of reinforced polymers, including particulate-reinforced polymers, short-fiber reinforced polymers (SFRP), continuous unidirectional fiber reinforced polymers (FRP), particulate-filled composites, mixed composites (SFRP and particulate-filled), unidirectional FRP composites, and fabric reinforced composites. Friction and wear performance of the composites, correlation of performance with various materials properties, and studies on wear-of failure mechanisms by scanning electron microscopy are discussed for each of these types.

Hybrid laser arc welding (HLAW) is a metal joining process that combines laser beam welding (LBW) and arc welding in the same weld pool. This article provides a discussion on the major process variables for two modes of operation of HLAW, namely, stabilization mode and penetration mode. The major process variables for either mode of operation include three sets of welding parameters: the variables for the independent LBW and gas metal arc welding processes and welding variables that are specific to the HLAW process. The article discusses the advantages, limitations, and applications of the HLAW and describes the major components and consumables used for HLAW. The components include the laser source, gas metal arc welding source, hybrid welding head, and motion system. The article also describes the typical sources of defects and safety concerns of HLAW.

Reinforced polymers (RPs) are widely used in structural, industrial, automotive, and engineering applications due to their ecofriendly nature and the potential to manipulate their properties. This article addresses the technical synthesis of RPs, referring to their tribological behavior, to provide insights into the contribution and interaction of influential parameters on the wear behavior of polymers. It provides a brief discussion on the effects of significant parameters on RP tribology. The article describes abrasive and adhesive wear and provides a theoretical synthesis of the literature regarding the wear mechanisms of RPs. It also describes the synthesis of abrasive wear failure of different types of RPs and highlights the contribution of these influential parameters. The article addresses the synthesis of adhesive wear failure of different types of RPs.

Metal matrix composites (MMCs) can be synthesized by vapor phase, liquid phase, or solid phase processes. This article emphasizes the liquid phase processing where solid reinforcements are incorporated in the molten metal or alloy melt that is allowed to solidify to form a composite. It illustrates the three broad categories of MMCs depending on the aspect ratio of the reinforcing phase. The categories include continuous fiber-reinforced composites, discontinuous or short fiber-reinforced composites, and particle-reinforced composites. The article discusses the two main classes of solidification processing of composites, namely, stir casting and melt infiltration. It describes the effects of reinforcement present in the liquid alloy on solidification. The article examines the automotive, space, and electronic packaging applications of MMCs. It concludes with information on the development of select cast MMCs.

Two-component polyurea elastomeric coating/lining systems are the newest technology in the protective coating/lining industry and a wide variety of applications have been developed. These include coating/lining applications over concrete, geotextile membranes, various metals for corrosion and decorative areas, and some plastics. This article discusses the formulation basics of polyurea technology and compares the technology to that of polyurethane and polyurethane/polyurea systems. It addresses performance issues and describes application processing considerations and safety practices of polyurea coating/lining systems.

This article focuses on the sample preparation methods for titanium honeycomb composites, boron fiber composites, and titanium/polymeric composite hybrids. These include mounting, sectioning, grinding, and polishing. The article also provides information on the sample preparation of unstaged and staged prepreg materials for optical analysis.

This article reviews various rapid prototyping (RP) processes such as stereolithography, powder sintering, hot melt extrusion, sheet lamination, solid ground curing, and three-dimensional printing. It discusses the various material prototypes produced by RP technology. The list of materials includes particulate and fiber-reinforced polymers, ceramic-matrix composites, and metal-matrix composites. The article also provides information on freeform-fabrication techniques for composite part lay-up.

Ultrasonic additive manufacturing (UAM) is a solid-state hybrid manufacturing technique that leverages the principles of ultrasonic welding, mechanized tape layering, and computer numerical control (CNC) machining operations to create three-dimensional metal parts. This article begins with a discussion on the process fundamentals and process parameters of UAM. It then describes metallurgical aspects in UAM. The article provides a detailed description of a wide range of mechanical characterization techniques of UAM, namely tensile testing, peel testing, and pushpin testing. The article ends with information on sensor embedding.

Joining is key to the manufacture of large or complex devices or assemblies; construction of large and complex structures; and repair of parts, assemblies, or structures in service. This article describes the three forces for joining: physical, chemical, and mechanical. It provides an overview of the joining processes, namely, mechanical fastening, integral attachment, adhesive bonding, welding, brazing, and soldering. The article concludes with information on the various aspects of joint design and location that determine the selection of a suitable joining method.

Composites, particularly fiber-reinforced polymer materials, are increasingly being adopted or considered as alternatives to conventional materials for civil infrastructure applications, such as bridges, buildings, waterfront structures, waste treatment facilities, and facilities for transmission and transport of utilities. This article provides information on seismic retrofit applications and discusses the repair and strengthening of components, such as beams, slabs, large-diameter pipes, and bridge decks.

This article provides information on the applications of fiber-reinforced composites in commercial and military aircrafts. It tabulates the composite components in various types of aircraft. The applications of the composites in the components of Boeing 727, 737, 757, 767, 777, and 777-200 are schematically illustrated.

This article discusses the application of friction stir processing (FSP) and friction surfacing for tribological components. It describes the three critical aspects involved in the application of FSP for near-surface material modifications intended for tribological applications. These include tools, processing parameters, and machines. The article also discusses the equipment and processing parameters for friction surfacing. It describes various hybrid stir processing techniques that involve preheating of the workpiece material, especially relatively hard and high-strength ones. The article presents a partial list of surface-modification methods based on FSP. The partial list includes surface hardening, surface composites, and additive coating. The article also provides information on generation of residual stresses in metallic materials and alloys form different variants of FSP.

Rapid prototyping (RP) is a field in manufacturing involving techniques/devices that produce prototype parts directly from computer-aided design models in a fraction of time. This article discusses the principles of RP and three major commercial processes, based on their layer creation method. These include selective cure layered processes, extrusion/droplet deposition processes, and sheet form fabricators. The article provides information on the three classes of RP, namely, voxel sequential volume addition, periphery cutting, and area sequential volume addition. It presents equations that represent build times for each of the three classes.

Calcium phosphates react to form more stable salts in aqueous solutions. This phenomenon has been applied to the solidification process for the dental and medical cement calcium phosphate cement, which consists of multiple phases of calcium phosphates and calcium salts; solidification occurs by the formation of hydroxyapatite. Dicalcium phosphate consists of crystal water along with anhydrous and dihydrate salts. This article summarizes research achievements regarding dicalcium phosphate dihydrate (DCPD) production with controlled morphology and reactivity, including effects of an additive and of production conditions on precipitation. It also summarizes achievements made in the hybridization of nano-apatite onto DCPD particles.