Specimen preparation is the first step that determines the quality of the microstructural information that can be obtained using optical microscopy. This chapter describes the sample preparation methods that are applicable to most types of composite materials containing short discontinuous or continuous fibers. The sample preparation methods cover documentation and labeling of samples, sectioning the composite, clamp-mounting composite samples, mounting composite samples in casting resins, and the addition of contrast dyes to casting resins. Information on the molds used for mounting composite materials is provided. The steps recommended to achieve a good mounted specimen without voids or specimen pull-out are also described. The chapter discusses the processes for clamping mounted composite samples in automated polishing heads and mounting composite materials for hand polishing. A summary of the mounting technique is also included.

This chapter discusses the fatigue behavior of bolted, riveted, and welded joints. It describes the relative strength of machined and rolled threads and the effect of thread design, preload, and clamping force on the fatigue strength of bolts made from different steels. It explains where fatigue failures are likely to occur in cold-driven rivet and friction joints, and why the fatigue strength of welded joints can be much lower than that of the parent metal, depending on weld shape, joint geometry, discontinuities, and residual stresses. The chapter also explains how to improve the fatigue life of welded joints and discusses the factors that can reduce the fracture toughness of weld metals.

Fiber-reinforced metal-matrix composites have carved out a niche in applications requiring high strength to weight ratios, but they are susceptible to failure when exposed to high temperatures and cyclic loads. This chapter discusses the obstacles that must be overcome to improve the creep-fatigue behavior of these otherwise promising materials. It addresses six areas that have been the focus of intense research, including thermal-expansion and elastic-viscoplastic mismatch, thermally induced biaxiality and interply stresses, creep and cyclic relaxation of residual stresses, and enhanced interfaces for oxidation.

Resistance welding is a group of processes in which the heat for welding is generated by the resistance to the flow of an electrical current through the parts being joined. This chapter discusses the processes, advantages, and limitations of specific resistance welding processes, namely resistance spot welding, resistance seam welding, projection welding, flash welding, and upset welding.

After the failure analysis team hypothesizes failure causes, prepares a failure mode assessment and assignment, and evaluates all potential failure causes, it may find in some cases that several causes are still suspect but cannot be confirmed. In this situation, an experiment is necessary to confirm or rule out suspected causes. This chapter discusses two predominant methods for doing this, namely analysis of variance (ANOVA) and Taguchi methods (a more powerful technique based on ANOVA).

This chapter covers basic machining and assembly operations, with an emphasis on hole preparation for mechanical fasteners. It describes manual, power feed, and automated drilling techniques as well as reaming and countersinking. It discusses various types of fasteners, including rivets, pins, and bolts, along with selection factors and special considerations for composite joints. It also includes information on interference-fit and blind fasteners as well as trimming operations, general assembly considerations, and sealing and painting procedures.

This chapter discusses the design and operation of hydraulic presses. It begins by describing the role of each major component in a hydraulic system. It then explains the difference between pump-driven and accumulator-driven presses and the types of applications for which are suited. The chapter goes on to describe the load, energy, and time-dependent characteristics of hydraulic presses and the factors that determine accuracy. It also explains how hydraulic presses are used for deep drawing, fine blanking, and hydroforming as well as warm forming and hot stamping operations.

Tube hydroforming is a material-forming process that uses pressurized fluid to plastically deform tubular materials into desired shapes. It is widely used in the automotive industry for making exhaust manifolds, catalytic converters, shock absorber housings, and other parts. This chapter discusses the basic methods of tube hydroforming and the underlying process mechanics. It explains how to determine if a material is a viable candidate and whether it can withstand preforming or bending operations. It describes critical process parameters, such as interface pressure, surface expansion and contraction, and sliding velocity, and how they influence friction, lubrication, and wear. The chapter also provides information on forming presses and tooling, tube hydropiercing, and the use of finite elements to determine optimal processing conditions and loading paths.

This chapter discusses the primary methods used to repair composites, including fill repairs, injection repairs, bolted repairs, and bonded repairs. It also discusses issues associated with field repairs.

This chapter discusses the design and application of sheet forming presses. The discussion covers critical variables and design parameters, key components, basic machine configurations, and energy and load requirements. The chapter also discusses time-dependent characteristics, dimensional accuracy, and stiffness as well as die change procedures.

This chapter focuses on tensile testing of three types of engineering components that undergo significant loading in tension, namely, threaded fasteners and bolted joints; adhesive joints; and welded joints. It describes the standardized tensile test for externally threaded fasteners and provides a brief background on relationships among torque, angle-of-turn, tension, and friction. The chapter also describes the test methods covered in the ASTM F 606M standard, namely, product hardness; proof load by length measurement, yield strength, or uniform hardness; axial tension testing of full-sized products; wedge tension testing of full-sized products; tension testing of machined test specimens; and total extension at fracture testing. Finally, the chapter covers tensile testing of adhesive and welded joints.

This chapter presents a comprehensive coverage of mechanical fastening methods. It begins with a discussion on the advantages and disadvantages of mechanical fastening followed by sections providing information on mechanically fastened joints and the selection of the correct fastener system. The chapter then describes important structural fasteners, namely bolts, screws, pins, collar fasteners, rivets, blind fasteners, machine pins, and spring clip fasteners. The following sections describe the process involved in presses, shrink fits, hole generation, and fastener installation. The chapter ends with information on miscellaneous mechanical fastening methods.

Plastic gears are continuing to displace metal gears in applications ranging from automotive components to office automation equipment. This chapter discusses the characteristics, classification, advantages, and disadvantages of plastics for gear applications. It provides a comparison between the properties of metals and plastics for designing gears. The chapter reviews some of the commonly used plastic materials for gear applications including thermoplastic and thermoset gear materials. The chapter also describes the processes involved in plastic gear manufacturing.

This chapter instructs the metallographer on the basic skills required to prepare a polished metallographic specimen. It is organized in a chronological sequence starting with the information-gathering process on the material being investigated, then moving on to sectioning, mounting, grinding, and polishing processes, and ending with methods used to properly store metallographic specimens. The discussion covers the preparation procedures, the materials being investigated, and equipment used to perform these procedures.

This chapter discusses the operating mechanism, applications, advantages, and limitations of Brinell hardness testing, Rockwell hardness testing, Vickers hardness testing, Scleroscope hardness testing, and microhardness testing. In addition, the general precautions and selection criteria to be considered are described and details of equipment setup provided.

This article presents best practices for the metallographic preparation of specimens produced via thermal spray coating methods. It outlines typical metallographic preparation process flow, highlighting important considerations for obtaining a clear and representative specimen suitable for characterization via examination techniques, such as optical or electron microscopy. The process flow includes preliminary resin infiltration, sectioning, mounting, grinding, and polishing. To aid in the identification and resolution of common issues during subsequent specimen analysis, the article presents common issues, along with causes and mitigation strategies. It describes the processes involved in the interpretation of the thermal spray coating microstructure.

This chapter describes joining by forming processes including riveting, clinching, crimping, and dieless joining techniques. It also discusses the fatigue behavior of clinched joints and the results of fatigue tests that compare clinched and spot welded joints.

This chapter discusses the effect of fiber length and orientation on the strength and stiffness of discontinuous-fiber composites. It also describes several fabrication processes, including spray-up, compression molding, reaction injection molding, and injection molding.

Sheet metal spinning is a forming technique that produces axially symmetric hollow bodies with nearly any contour. It is often used in combination with flow forming and shear spinning to manufacture a wide range of complex parts. This chapter describes the operating principles, stress states, and failure modes of each process along with typical applications and tooling requirements.

The testing of plastics includes a wide variety of chemical, thermal, and mechanical tests. This chapter reviews the tensile testing of plastics, which has been standardized in ASTM D 638, "Standard Test Method for Tensile Properties of Plastics," and other comparable standards. It describes the fundamental factors that affect data from tensile tests, examines the stipulations in standardized tensile testing, and discusses the utilization of data from tensile tests.