This article discusses the chemical susceptibility of a polymeric material. The discussion covers significant absorption and transportation of an environmental reagent by the polymer; the chemical susceptibility of additives; and thermal degradation, thermal oxidative degradation, photo-oxidative degradation, environmental corrosion, and chemical corrosion of polymers. It also includes some of the techniques used to detect changes in structure during polymer exposure to hostile environments. In addition, the article describes the effects of environment on polymer performance, namely plasticization, solvation, swelling, environmental stress cracking, polymer degradation, surface embrittlement, and temperature effects.

This article provides a basic review of polymer photochemistry as it relates to the weatherability of engineering plastics, considering the chemistry induced by exposure to sunlight in open air. Elementary aspects of weatherability chemistry that are discussed include the light wavelengths responsible for polymer photochemistry, problems with artificial light sources, general photooxidation and specific photochemical reactions important in plastics, and the factors influencing the rate of degradation. The approaches used to stabilize plastics against photochemical damage, including ultraviolet light absorbers, oxidation inhibitors, and the use of protective coatings, are also considered.

Polymer composite materials are subject to degradation if not appropriately protected from the environment. Composite materials having polymeric matrices are susceptible to degradation from heat, sunlight, ozone, atomic oxygen (in space), moisture, solvents (chemicals), fatigue, excessive loading, and combinations of these environmental conditions. This chapter discusses the effects of heat, ultraviolet-light, and atomic oxygen on composite materials.

This article provides a review of the biodegradation mechanisms of plastics, presents the definitions, and describes the means of measurement of biodegradation and biodeterioration. Various experimental examples of microbial degradation, namely fungal attack in cellophane and amylose films, starch-based polyethylene films, films with modified starch additives, poly(3-hydroxybutyrate-valerate)-biodegradable plastic, and biodisintegration and biodegradation studies of plastic-starch blends, are also presented.

Optoelectronic components can be readily classified as active light-emitting components (such as semiconductor lasers and light emitting diodes), electrically active but non-emitting components, and inactive components. This chapter focuses on the first category, and particularly on semiconductor lasers. The discussion begins with the basics of semiconductor lasers and the material science behind some causes of device failure. It then covers some of the common failure mechanisms, highlighting the need to identify failures as wearout or maverick failures. The chapter also covers the capabilities of many key optoelectronic failure analysis tools. The final section describes the common steps that should be followed so as to assure product reliability of optoelectronic components.

This chapter discusses the maintenance needs of major components in induction heat-treating systems, including power supplies, heat stations, capacitors, high-frequency output stages, induction coils, water systems, quench systems, and fixturing.

This chapter covers the fatigue and fracture behaviors of ceramics and polymers. It discusses the benefits of transformation toughening, the use of ceramic-matrix composites, fracture mechanisms, and the relationship between fatigue and subcritical crack growth. In regard to polymers, it covers general characteristics, viscoelastic properties, and static strength. It also discusses fatigue life, impact strength, fracture toughness, and stress-rupture behaviors as well as environmental effects such as plasticization, solvation, swelling, stress cracking, degradation, and surface embrittlement.

This article reviews various analytical techniques most commonly used in plastic component failure analysis. The description of the techniques is intended to make the reader familiar with the general principles and benefits of the methodologies. The descriptions of the analytical techniques are supplemented by a series of case studies that include pertinent visual examination results and the corresponding images that aided in the characterization of the failures. The techniques covered include Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, thermomechanical analysis, and dynamic mechanical analysis. The article also discusses various analytical methods used to characterize the molecular weight distribution of a polymeric material. It provides information on a wide range of mechanical tests that are available to evaluate plastics and polymers, covering the various considerations in the selection and use of test methods.

This chapter describes the conditions under which environmental degradation is likely to occur in polymer matrix composites and the potential damage it can cause. It discusses the problems associated with moisture absorption and exposure to solvents, fuels, ultraviolet radiation, lightning strikes, thermal oxidation, and extreme temperatures. It also discusses the factors that influence flammability.

This article presents a general overview of outdoor weather aging factors, their effects on plastic materials, and the accelerated test methods that can be used to estimate the reaction of a plastic component during actual use. Weather and radiation factors that contribute to degradation in plastics include temperature variations, moisture, sunlight, oxidation, microbiologic attack, and other environmental elements. The article also describes the tests used to predict the behavior of a plastic material to outdoor exposure, discussing the use of xenon arc lamp for the weatherometer and fadeometer and the use of fluorescent sunlamp in test devices.

Irradiation-assisted stress-corrosion cracking (IASCC) has been a topic of engineering interest since it was first reported in the 1960s, having been observed in stainless steel cladding on light water reactor fuel elements. This chapter summarizes the results of decades of investigation, showing that IASCC can essentially be defined as the intergranular cracking of austenitic alloys in high-temperature water, where both the material and its environment have been altered by radiation. Of the many interactions that can occur when metals and water are exposed to radiation, the international consensus is that the three with the greatest impact on crack growth rates are the formation of material defects, radiation-induced segregation, and chemical reactions that increase the corrosion potential of water. The chapter discusses each of these in great detail, and includes information on predictive modeling as well.

Hydrogen damage is a form of environmentally assisted failure that results most often from the combined action of hydrogen and residual or applied tensile stress. This chapter classifies the various forms of hydrogen damage, summarizes the various theories that seek to explain hydrogen damage, and reviews hydrogen degradation in specific ferrous and nonferrous alloys. The preeminent theories for hydrogen damage are based on pressure, surface adsorption, decohesion, enhanced plastic flow, hydrogen attack, and hydride formation. The specific alloys covered are iron-base, nickel, aluminum, copper, titanium, zirconium, vanadium, niobium, and tantalum alloys.

This article describes the mechanisms of moisture-induced damage in polymeric materials, covering the characteristics of important structural plastics; the effects of moisture on glass transition temperature, modulus, creep, and stress relaxation of plastic materials; and moisture-induced fatigue failure in composites. The effect of moisture on the mechanical properties of thermoset resins and thermoplastics are also discussed.

Superalloys tend to operate in environments where they are subjected to high-temperature corrosion, oxidation, and the erosive effects of hot gases. This chapter discusses the nature of these attacks and the effectiveness of various protection methods. It describes the primary forms of oxidation, the development of protective oxides, and the conditions associated with mixed gas corrosion and hot corrosion attack. It discusses oxidation and corrosion testing, the equipment used, and various ways to present the associated data. It describes the effect of gaseous oxidation on different alloys, discusses the formation of oxide scale in the presence of mixed gases, and explains how alloy composition contributes to oxide growth. The chapter discusses the underlying chemistry of hot corrosion, how to identify its effects, and how it progresses under various conditions. It also discusses protective coatings, including aluminide diffusion, overlay, and thermal barrier types, and how they perform in different environments based on their ability to tolerate strain.

This chapter concentrates almost exclusively on inspection techniques related to pressure vessels and pipework. The discussion covers the general aspects associated with inspection and the key factors relevant to it. In addition, the chapter addresses processes involved in data collection and management, namely data acquisition, reporting, trending, reviewing, and auditing. Capabilities and limitations of in-service inspection techniques are discussed in the Appendix to this chapter.

This chapter discusses the importance of failure analysis and the role it plays in a society driven by technological advancement. It explains why failure rates are highest in the early and later stages of the life of any product and shows the extent to which failure rates increase when products are subjected to an aggressive operating environment.

Combustion turbines consist of a compressor, a combustor, and a turbine. As commonly configured, the compressor and turbine mount on a single shaft that connects directly to a generator. This chapter reviews the materials of construction, damage mechanisms, and life-assessment techniques for nozzles and buckets. It also presents key information from a detailed review of the literature and the results of a survey on combustion-turbine material problems.

This chapter discusses five forms of mechanically assisted degradation of metals: erosion, fretting, fretting fatigue, cavitation and water drop impingement, and corrosion fatigue. Emphasis is placed on the mechanisms and the factors affecting these forms of degradation.