This chapter provides an overview of the various inspection methods used with metals and alloys, namely visual inspection, coordinate measuring machines, machine vision, hardness testing, tensile testing, chemical analysis, metallography, and nondestructive testing. The nondestructive testing methods discussed are liquid penetrant inspection, magnetic particle inspection, eddy current inspection, radiographic inspection, and ultrasonic testing.

The overall chemical composition of metals and alloys is most commonly determined by x-ray fluorescence (XRF) and optical emission spectroscopy (OES). High-temperature combustion and inert gas fusion methods are typically used to analyze dissolved gases (oxygen, nitrogen, and hydrogen) and, in some cases, carbon and sulfur in metals. This chapter discusses the operating principles of XRF, OES, combustion and inert gas fusion analysis, surface analysis, and scanning auger microprobe analysis. The details of equipment set-up used for chemical composition analysis as well as the capabilities of related techniques of these methods are also covered.

After the fault-tree, a failure-cause identification method has identified potential failure causes and the failure analysis team has prepared a failure mode assessment and assignment (FMA&A). The team knows specifically what to search for when examining components and subassemblies from the failed system. There are numerous techniques and technologies available for examining and analyzing components and subassemblies, which are categorized as follows: optical approaches, dimensional inspection and related approaches, nondestructive test approaches, mechanical and environmental approaches, and chemical and composition analysis for assessing material characteristics. This chapter is a detailed account of the working principle and the steps involved in these techniques and technologies.

This chapter describes the procedures and processes used to chemically analyze beryllium samples. It discusses gravimetric, volumetric, colorimetric, and fluorometric techniques, radiochemical separation and assay, and the use of emission spectrometry and polarographic methods.

This chapter provides an overview of the possible mechanisms of failure for heat treated steel components and discusses the techniques for examining fractures, ductile and brittle failures, intergranular failure mechanisms, and fatigue. It begins with a description of the general sources of component failure. This is followed by a section on the stages of a failure analysis, which can proceed one after the other or occur at the same time. These stages of analysis are collection of background data, preliminary visual examination, nondestructive testing, selection and preservation of specimens, mechanical testing, macroexamination, microexamination, metallographic examination, determination of the fracture mechanism, chemical analysis, exemplar testing, and analysis and writing the report. The chapter ends with a discussion on various processes involved in the determination of the fracture mechanism.

This chapter addresses in-service monitoring and corrosion testing of weldments. Three categories of corrosion monitoring are discussed: direct testing of coupons, electrochemical techniques, and nondestructive testing techniques. The majority of the test methods for evaluating corrosion of weldments are used to assess intergranular corrosion of stainless steels and high-nickel alloys. Other applicable tests evaluate pitting and crevice corrosion, stress-corrosion cracking, and microbiologically influenced corrosion. Each of these test methods is reviewed in this chapter.

An aircraft went down over water some 30 minutes into a flight. The wreckage was retrieved and the elevator linkage components were dismantled, cleaned, and reassembled. As the chapter explains, both the port and starboard hinge pins had fractured at a tack welded joint along a flange. Based on visual examination, SEM fractography, and chemical analysis, investigators concluded that the hinge pins were not made from the specified steel and were not properly treated after cadmium plating. The pins failed due to hydrogen embrittlement, which may have been aggravated by welding. The chapter provides several recommendations to avoid such failures in the future.

This article focuses on characterization techniques used for analyzing the physical behavior and chemical composition of thermoset resins, namely chromatography and infrared spectroscopy. The main purpose is to give sufficient detail to permit the reader understand a particular test technique and its value to the thermoset resin field. Epoxy resins are emphasized in the examples because they dominate the airframe and aerospace industries. The article also provides information on two categories of characterization of the processing behavior of thermoset. The first studies the thermal properties of reactive thermoset systems, while the second utilizes these thermal characteristics as the basis for monitoring and control during processing.

This article addresses some established protocols in characterizing thermoplastics, whether they are homogeneous resins, alloyed or blended compositions, or highly modified thermoplastic composites. It begins with a description of various approaches used for the determination of molecular weight (MW) by viscosity measurements. This is followed by a discussion of the use of cone and plate and parallel plate geometries in determining the viscoelastic properties of a polymer melt. Details on some of the chromatographic techniques that allow determination of MW and MW distribution of polymers are then provided. The article concludes with information on three distinctive, but complementary operations of thermoanalytical techniques, namely differential scanning calorimetry, thermogravimetric analysis, and thermomechanical testing.

This chapter discusses the techniques applicable to the diagnosis of corrosion failures, including visual and microscopic examination of corroded surfaces and microstructure; chemical analysis of the metal, corrosion products, and bulk environment; nondestructive evaluation methods; corrosion testing techniques; and mechanical testing techniques. A guide to investigative techniques used in corrosion failure analysis is provided in a table, describing the advantages and limitations of each technique. The principal stages of the investigation and analysis of corrosion failures discussed in the chapter are: collection of background information and sampling; preliminary laboratory examination; detailed metallographic and fractographic examinations; chemical analysis of corrosion products and bulk materials; corrosion testing for quality control; mechanical testing for quality control; and analysis of results and report writing.

This chapter discusses corrosion prevention methods used with aluminum and its alloys. The methods range from relatively straightforward measures, such as proper handling and storage, to advanced early warning corrosion monitoring systems for military aircraft. The chapter summarizes the basic factors that influence design for corrosion resistance and discusses the use of conversion coatings, organic coatings, porcelain enameling, and electroplating. It also discusses corrosion monitoring methods used in chemical processing and refining industries.

This chapter provides an overview of the types of melting furnaces and refractories for steel casting. It then presents information about arc furnace melting and induction melting cycles. The chapter also describes methods for the removal of phosphorous, the removal of sulfur, and the recovery of elements from slag. It then presents an overview of argon-oxygen-decarburization (AOD) refining and types of ladles. The chapter describes chemical analysis that is performed using either optical emission or x-ray spectrographs.

This chapter discusses field, visual, physical, and metallurgical examinations of gear failures. Physical examinations reviewed include nondestructive testing, including magnetic-particle inspection, tooth characteristic studies, surface hardness testing, ultrasonic testing, nital etching, profilometer measurements, and dimensional checking. Metallurgical examinations reviewed include the cross-sectional hardness survey, macroscopic examination, carbon gradient traverse, chemical analysis, case hardness traverse [microhardness], microscopic examination, and scanning electron microscopy.