This article is a detailed account of the mechanisms of fatigue failure of polymers, namely thermal fatigue failure and mechanical fatigue failure. The mechanical fatigue failure is discussed in terms of fatigue crack initiation and fatigue crack propagation.

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 focuses on common failure characteristics exhibited by mechanical and electrical components. The topic is considered from two perspectives: one possibility is that the system failed because parts were nonconforming to drawing requirements and another possibility is that the system failed even though all parts in the system met their drawing requirements. The common failures discussed in this chapter include those associated with metallic components, composite materials, plastic components, ceramic components, and electrical and electronic components.

As fiber-reinforced polymeric composites continue to be used in more damage-prone environments, it is necessary to understand the response of these materials when subjected to impact from foreign objects. This chapter provides an overview of the analysis methods for impact-damaged composites. It discusses the causes and effects of various failure mechanisms in composite materials. The failure mechanisms covered are brittle-matrix composite failure, tough-matrix composite failure, thermoplastic-matrix composite failure mechanisms, untoughened thermoset-matrix composite failure mechanisms, toughened thermoset-matrix composite failure mechanisms, particle interlayer-toughened composite failure mechanisms, and dispersed-phase, rubber-toughened thermoset-matrix composite failure mechanisms.

The honeycomb sandwich structure composite is a very efficient and complex structure widely used in the aircraft industry. Honeycomb-cored sandwich panels increase part stiffness at a lower weight than monolithic composite materials. This chapter describes the analysis of the intermingling of the film adhesive/prepreg resin system. It discusses the causes and effects of honeycomb core movement, which results in core crush. The chapter also explains the formation of a void in honeycomb composites and the failure mechanisms in honeycomb sandwich structure composites.

This chapter reviews various ways to classify failure categories and summarizes the basic types, causes, and mechanisms of damage, with particular consideration given to whether the likelihood of the types of damage can or cannot be influenced by the heat treating of steel parts. The classical organization for types of damage (failures) is as follows: deformation, fracture, wear, corrosion or other environmental damage, and multiple or complex damage. The chapter also provides some examples of lack of conformance to specification that may at first look like the heat treater did something wrong, but where other contributing factors made it difficult or impossible for the heat treater to meet the specification.

This chapter discusses the various failure analysis techniques for microelectromechanical systems (MEMS), focusing on conventional semiconductor manufacturing processes and materials. The discussion begins with a section describing the advances in integration and packaging technologies that have helped drive the further proliferation of MEMS devices in the marketplace. It then shows some examples of the top MEMS applications and quickly discusses the fundamentals of their workings. The next section describes common failure mechanisms along with techniques and challenges in identifying them. The chapter also provides information on the testing of MEMS devices. It covers the two common challenges in sample preparation for MEMS: decapping, or opening up the package, without disturbing the MEMS elements; and removing MEMS elements for analysis. Finally, the chapter discusses the aspects of failure analysis techniques that are of particular interest to MEMS.

Elevated-temperature failures are the most complex type of failure because all of the modes of failures can occur at elevated temperatures (with the obvious exception of low-temperature brittle fracture). Elevated-temperature problems are real concerns in industrial applications. The principal types of elevated-temperature failure mechanisms discussed in this chapter are creep, stress rupture, overheating failure, elevated-temperature fatigue, thermal fatigue, metallurgical instabilities, and environmentally induced failure. The causes, features, and effects of these failures are discussed. The cooling techniques for preventing elevated-temperature failures are also covered.

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 failure mechanisms associated with fiber-reinforced composites. It begins with a review of fiber-matrix systems and the stress-strain response of unidirectional lamina and both notched and unnotched composite laminate specimens. It then explains how cyclic loading can lead to delamination, the primary failure mode of most composites, and describes some of the methods that have been developed to improve delamination resistance, assess damage tolerance, determine residual strength, and predict failure modes.

This article introduces the subject of fractography and how it is used in failure analysis. The discussion covers the structure of and fracture and crack-propagation behavior of polymeric materials, the distinction between the ductile and brittle fracture modes on the basis of macroscopic appearance, and the examination and interpretation of the features of fracture surfaces. In addition, the article considers several cases of field failure in various polymers to illustrate the applicability of available analytical tools in conjunction with an understanding of failure mechanisms.

This chapter presents various case histories that illustrate a variety of failure mechanisms experienced by the high-strength steel components in aerospace applications. The components covered are catapult holdback bar, AISI 420 stainless steel roll pin, main landing gear (MLG) lever, inboard flap hinge bolt, nose landing gear piston axle, multiple-leg aircraft-handling sling, aircraft hoist sling, internal spur gear, and MLG axle. In addition, the chapter provides information on full-scale fatigue testing, nondestructive testing, and failure analysis of fin attach bolts.

Most of the counterfeit parts detected in the electronics industry are either novel or surplus parts or salvaged scrap parts. This article begins by discussing the type of parts used to create counterfeits. It discusses the three most commonly used methods used by counterfeiters to create counterfeits. These include relabeling, refurbishing, and repackaging. The article presents a systematic inspection methodology that can be applied for detecting signs of possible part modifications. The methodology consists of external visual inspection, marking permanency tests, and X-ray inspection followed by material evaluation and characterization. These processes are typically followed by evaluation of the packages to identify defects, degradations, and failure mechanisms that are caused by the processes (e.g., cleaning, solder dipping of leads, reballing) used in creating counterfeit parts.

This chapter describes several macroscopic examination techniques, including macroetching, contact printing, fracturing, and lead exudation. It explains how each method is implemented, why it is used, and what it reveals about manufacturing processes, defects, imperfections, and failure mechanisms.

This chapter provides a brief review of industry’s battle with fatigue and fracture and what has been learned about the underlying failure mechanisms and their effect on product lifetime and service. It recounts some of the tragic events that led to the discovery of fatigue and brittle fracture and explains how they reshaped design philosophies, procedures, and tools. It also discusses the influence of material and manufacturing defects, operating conditions, stress concentration and intensity, temperature and pressure, and cyclic loading, all of which play a role in the onset of fatigue cracking and thus should be considered when predicting useful product life.

This chapter provides an outline of the failure modes and mechanisms associated with most boiler tube failures in coal-fired power plants. Primary categories include stress rupture failures, water-side corrosion, fire-side corrosion, fire-side erosion, fatigue, operation failures, and insufficient quality control.

This chapter surveys both basic quality and basic reliability concepts as an introduction to the failure analysis professional. It begins with a section describing the distinction between quality and reliability and moves on to provide an overview of the concept of experiment design along with an example. The chapter then discusses the purposes of reliability engineering and introduces four basic statistical distribution functions useful in reliability engineering, namely normal, lognormal, exponential, and Weibull. It also provides information on three fundamental acceleration models used by reliability engineers: Arrhenius, Eyring, and power law models. The chapter concludes with information on failure rates and mechanisms and the two techniques for uncovering reliability issues, namely burn-in and outlier screening.

Many companies conduct only metallurgical evaluations in the wake of failures, discovering nothing more than the physical mechanism by which the failure occurred. The origin of failures, however, is often complex, involving not only physical mechanisms, but also human behavior and latent factors. Failures may also involve multiple parts, entire machines, or processes of any size and shape. The chapter examines the unique aspects of many failures and explains how they can sometimes be traced to systemic issues. It also covers the reasons why products fail, including improper service or operation, improper maintenance, improper testing, assembly errors, fabrication or manufacturing errors, and design errors. The case of the Tacoma Narrows Bridge collapse is presented to illustrate the consequence of overlooked factors, in this case, wind dynamics, and the importance of identifying root causes to prevent repeat failures.

This chapter covers the failure modes and mechanisms associated with boiler components and the tools and techniques used to assess damages and predict remaining component life. It begins with a review of the design and operation of a utility boiler and the materials used in construction. It then describes the various causes of failure in boiler tubes, headers, and steam pipes, explaining how and why they occur, how they are diagnosed, and how to mitigate their effects. The final and by far largest section in the chapter is a tutorial on damage and life assessment techniques for boiler components and assemblies. It demonstrates the use of various methods, including analytical techniques that estimate life expenditure based on operating history, component geometry, and material properties; predictive methods based on the extrapolation of failure statistics; methods that predict life based on dimensional measurements; methods based on metallographic studies; methods based on temperature estimates; and a method for estimating remaining life under creep conditions based on stress-rupture testing of service-exposed material samples. The chapter also discusses the use of fracture mechanics and presents a number of cases in which life assessments are made based on the integration of several methods.

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.