This article describes how composite specimens are sectioned, documented, and labeled during sample preparation. The mounting procedures for the specimen are summarized. The article explains sample clamping, which involves not mounting the specimens using an adhesive or casting resin and corresponds to clamped samples used in automated polishing heads. It details that cavity molds involve mounting the composite specimens using a casting resin in a preset mold. The article also discusses the mounting of composite materials for hand polishing.

Lightning damage in polymer composites is manifested by damage at both the macroscopic or visual level and within the material microstructure. This article illustrates the effects of the laboratory-generated lightning strikes on polymeric composites.

Honeycomb-cored sandwich panels increase part stiffness at a lower weight than monolithic composite materials. This article illustrates an area of a honeycomb-cored sandwich structure composite cross section that is viewed using transmitted polarized light. This area shows the differences in the constituents and resin intermingling. The article discusses the factors that govern the honeycomb core movement and honeycomb core crush, with illustrations. Some common tests performed on honeycomb composites to characterize the skin-to-core bond strength are the climbing drum peel and flatwise tensile tests. The article concludes with a description on the reasons for core failure, which are analyzed after these tests.

This article describes methods for analyzing impact-damaged composites in the aircraft industry. These include C-scan and x-radiography methods and optical microscopy. The article reviews brittle-matrix composite and tough-matrix composite failures. It explains the different types of composite failure mechanisms such as thermoplastic-matrix composite failure mechanisms, untoughened thermoset-matrix composite failure mechanisms, toughened thermoset-matrix composite failure mechanisms, dispersed-phase and rubber-toughened thermoset-matrix composite failure mechanisms, and particle interlayer-toughened composite failure mechanisms.

Mounting of the specimen is often desirable or necessary for handling and metallographic polishing after the specimen is cut into an appropriate size. This article illustrates the different mechanical clamps used in mounting small specimens. It provides useful information on compression molded mounts, which are molded with thermoplastic and thermosetting resins. The article reviews several resins and their key factors, which help in the selection of the most appropriate mounting method and resin. It also discusses the characteristics of plastic mounting materials. The article provides information on the molds and resins used for castable mounts, vacuum treatment of mounts, special mount arrangements, and mount marking and storage.

Shell molding is used for making production quantities of castings that range in weight from a few ounces to approximately 180 kg (400 lb), in both ferrous and nonferrous metals. This article lists the limitations or disadvantages of shell mold casting. It describes the two methods for preparation of resin-sand mixture for shell molding, namely, mixing resin and sand according to conventional dry mixing techniques, and coating the sand with resin. Shaping of shell molds and cores from resin sand mixtures is accomplished in machines. The article discusses the major steps in producing a mold or core and describes the problems most frequently encountered in shell-mold casting. The problems include mold cracking, soft molds, low hot tensile strength of molds, peelback, and mold shift. The article concludes with information on examples that provide some relative cost comparisons between shell molding and green sand molding.

In terms of their electrical properties, plastics can be divided into thermosetting and thermoplastic materials, some of which are conductive or semiconductive. This article provides detailed information on factors that affect the property of plastics. It discusses the major test methods used to determine the following dielectric properties of plastics: dielectric breakdown voltage, dielectric strength, dielectric constant, dissipation factor, arc tracking resistance, insulation resistance, volume, and surface resistivity or conductivity. The test specifications and conditions, recommended by several U.S. and foreign testing organizations for characterizing the electrical properties of plastic materials are listed. The article describes the influence of these properties on selection of plastics for insulation application. An outline of the electromagnetic shielding and testing methods of electromagnetic interference are also provided. Designations, electrical properties, and applications of elastomers are tabulated.

Casting can be done with either expendable molds for one-time use or permanent molds for reuse many times. This article lists the various methods used to fabricate expendable molds from permanent patterns. The methods include molding of sand with clay, inorganic binders, or organic resins; shell molding of sand with a thin resin-bonded shell; no-bond vacuum molding of sand; plaster-mold casting; ceramic-mold casting; rammed graphite molding; and magnetic (no-bond) molding of ferrous shot. The article tabulates a general comparison of casting methods and discusses the basic requirements of foundry molds.

This article discusses classification of foundry processes based on the molding medium, such as sand molds, ceramic molds, and metallic molds. Sand molds can be briefly classified into two types: bonded sand molds, and unbonded sand molds. Bonded sand molds include green sand molds, dry sand molds, resin-bonded sand molds, and sodium silicate bonded sand. The article describes the casting processes that use these molds, including the no-bake process, cold box process, hot box process, the CO2 process, lost foam casting process and vacuum molding process. The casting processes that use ceramic molds include investment casting, and plaster casting. Metallic molds are used in permanent mold casting, die casting, semisolid casting, and centrifugal casting.

Aggregate molding, or sand casting, is the gravity pouring of liquid metal into a mold that is made of a mixture molded against a permanent pattern. This article summarizes the most important materials in the process of sand casting of cast iron, including different types of molding aggregates, clays, water, and additives in green sand, chemically bonded organic resins, and inorganic binders in self-setting, thermosetting, and gas-triggered systems. It discusses three main types of reclamation systems: wet, dry, and thermal. The article concludes with a description of both nonpermanent and permanent mold processes.

This article describes key processing methods and related design, manufacturing, and application considerations for plastic parts. The methods include injection molding, extrusion, thermoforming, blow molding, rotational molding, compression molding/transfer molding, composites processing, and casting. The article describes principal features incorporated into the design of plastic parts. It concludes with a discussion on the materials selection methodology for plastics.