Analysis of the failure of a metal structure or part usually requires identification of the type of failure. Failure can occur by one or more of several mechanisms, including surface damage (such as corrosion or wear), elastic or plastic distortion, and fracture. This leads to a wide range of failures, including fatigue failure, distortion failure, wear failure, corrosion failure, stress-corrosion cracking, liquid-metal embrittlement, hydrogen-damage failure, corrosion-fatigue failure, and elevated-temperature failure. This article describes the classification of fractures on a macroscopic scale as ductile fractures, brittle fractures, fatigue fractures, and fractures resulting from the combined effects of stress and environment.

This article focuses on environmental and application factors in solid friction. It covers the tribology of contact between a soft and hard material, including mechanisms and testing. The article describes the tribology of contact between a metal and tool during metalworking processes. It also discusses the tribology of metal friction at elevated temperatures.

While there are many fracture mechanisms that can lead to the failure of a plastic component, environmental stress cracking (ESC) is recognized as one of the leading causes of plastic failure. This article focuses on unpacking the basic concepts of ESC to provide the engineer with a better understanding of how to evaluate and prevent it. It then presents factors that affect and contribute to the susceptibility of plastic to ESC: material factors, chemical factors, stress, and environmental factors. The article includes the collection of background information to understand the circumstances surrounding the failure, a fractographic evaluation to assess the cracking, and analytical testing to evaluate the material, design, manufacturing, and environmental factors.

This article describes weathering and environmental factors that contribute to degradation in plastics, including temperature variations, moisture, sunlight, oxidation, microbiologic attack, and other environmental elements. It presents a general overview of 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. The article focuses on the determination of service temperature as it indicates the ability of a material to retain a certain property, when exposed to elevated temperatures for an extended period of time. It concludes by describing various degradation processes, namely, thermal degradation, thermal oxidative degradation, photooxidative degradation, environmental corrosion, and chemical corrosion and discussing the ways of detecting these degradation processes.

The susceptibility of plastics to environmental failure, when exposed to organic chemicals, can limit their use in many applications. A combination of chemical and physical factors, along with stress, usually leads to a serious deterioration in properties, even if stress or the chemical environment alone may not appreciably weaken a material. This phenomenon is referred to as environmental stress cracking (ESC). The ESC failure mechanism for a particular plastics-chemical environment combination can be quite complex and, in many cases, is not yet fully understood. This article focuses on two environmental factors that contribute to failure of plastics, namely chemical and physical effects.

Engineering plastics offer unique product benefits based on physical properties, or combinations of physical properties, that allow vastly improved product performance. Providing an overview of the general characteristics and the mechanical and environmental stress response of engineering plastics, this article discusses various factors, including thermal, mechanical and electrical properties, environmental factors, and material cost that are important in the selection of engineering plastics for specific applications.

This article describes the general factors that can influence fracture appearances. The focus is on the general practical relationships of fracture appearances, with factors presented in some broad categories, including: material conditions (e.g., crystal structure and microstructure); loading conditions (stress state, strain rate, and fatigue); manufacturing conditions (casting, metal-working, machining, heat treatment, etc.); and service and environmental factors (hydrogen embrittlement, stress corrosion, temperature, and corrosion fatigue).

Overload failures refer to the ductile or brittle fracture of a material when stresses exceed the load-bearing capacity of a material. This article reviews some mechanistic aspects of ductile and brittle crack propagation, including a discussion on mixed-mode cracking, which may also occur when an overload failure is caused by a combination of ductile and brittle cracking mechanisms. It describes the general aspects of fracture modes and mechanisms. The article discusses some of the material, mechanical, and environmental factors that may be involved in determining the root cause of an overload failure. It also presents examples of thermally and environmentally induced embrittlement effects that can alter the overload fracture behavior of metals.

This article discusses the environmental influences on protective coating films that can result in deterioration. These environmental factors can be classified into four groups: (1) energy: solar, heat; (2) permeation: moisture, solvent, chemical, and gas; (3) stress: drying and curing-internal stress, and vibration-external stress; and (4) biological influences such as microbiological, mildew, and marine fouling.

Accelerated life testing and aging methodologies are increasingly being used to generate engineering data for determining material property degradation and service life (or fitness for purpose) of plastic materials for hostile service conditions. This article presents an overview of accelerated life testing and aging of unreinforced and fiber-reinforced plastic materials for assessing long-term material properties and life expectancy in hostile service environments. It considers various environmental factors, such as temperature, humidity, pressure, weathering, liquid chemicals (i.e., alkalis and acids), ionizing radiation, and biological degradation, along with the combined effects of mechanical stress, temperature, and moisture (including environmental stress corrosion). The article also includes information on the use of accelerated testing for predicting material property degradation and long-term performance.

Superalloys are nickel, iron-nickel, and cobalt-base alloys generally used for high-temperature applications. Superalloys are used in aircraft, industrial, marine gas turbines, nuclear reactors, spacecraft structures, petrochemical production, orthopedic and dental prostheses, and environmental protection applications. This article discusses the material characteristics, phases, structures, and systems of superalloys. It describes the processing of superalloys, including primary and secondary melting, deformation processing (conversion), powder processing, investment casting, and joining methods. The article also describes the properties, microstructure, and thermal exposure of superalloys. It further discusses the effects of environmental factors on superalloys, including oxidation and hot corrosion. Protective coatings are also discussed. The article provides information on the mechanical properties and chemical composition of nickel, iron, and cobalt-base superalloys in both the cast and wrought forms.

This article discusses the composition, properties and applications of bearing steels. It focuses on the typical wear modes that rolling-element bearings experience: contact fatigue wear, abrasive wear, adhesive wear, and corrosive wear. The article provides information on reliability factor and ABMA and ISO environmental factors.

This article briefly reviews the factors that influence the occurrence of intergranular (IG) fractures. Because the appearance of IG fractures is often very similar, the principal focus is placed on the various metallurgical or environmental factors that cause grain boundaries to become the preferred path of crack growth. The article describes in more detail some typical mechanisms that cause IG fracture. It discusses the causes and effects of IG brittle cracking, dimpled IG fracture, IG fatigue, hydrogen embrittlement, and IG stress-corrosion cracking. The article presents a case history on IG fracture of steam generator tubes, where a lowering of the operating temperature was proposed to reduce failures.

This article begins with a discussion on the environmental factors that induce corrosion in magnesium alloys. It reviews the factors that determine the severity of different forms of localized corrosion, namely, galvanic corrosion, corrosion fatigue, and stress-corrosion. The article discusses corrosion protection in magnesium assemblies and the protective coating systems used in corrosion protection practices. Protection schemes for specific applications and the production of novel magnesium alloys with improved corrosion resistance are also reviewed. The article concludes with a discussion on the corrosion of bulk vapor-deposited alloys and magnesium-matrix composites.

This article focuses on the corrosion-wear synergism in aqueous slurry and grinding environments. It describes the effects of environmental factors on corrosive wear and provides information on the impact and three-body abrasive-corrosive wear. The article also discusses the various means for combating corrosive wear, namely, materials selection, surface treatments, and handling-environment modifications.

This article briefly reviews the various metallurgical or environmental factors that cause a weakening of the grain boundaries and, in turn, influence the occurrence of intergranular (IG) fractures. It discusses the mechanisms of IG fractures, including the dimpled IG fracture, the IG brittle fracture, and the IG fatigue fracture. The article describes some typical embrittlement mechanisms that cause the IG fracture of steels.

This article describes the various environmental factors that cause corrosion on metal artifacts, which include water, temperature fluctuations, pollutants, local conditions of acidity or alkalinity, vegetation, and animals. The corrosion processes experienced by five common metals, such as copper alloys, iron alloys, lead, zinc, and aluminum, used in outdoor artifacts are discussed. Finally, the article reviews conservation and preservation strategies for these five as well as gilded metals.

This article discusses the effects of heavy metal impurities, environmental factors, the surface condition (such as as-cast, treated, and painted), and the assembly practice on the corrosion resistance of a magnesium or a magnesium alloy part. It provides information on stress-corrosion cracking and galvanic corrosion of magnesium alloys, as well as the surface protection of magnesium assemblies achieved by inorganic surface treatments.

This article discusses the environmental factors and kinetics of atmospheric corrosion, aqueous corrosion, and soil corrosion of carbon steels. It also provides information on corrosion in concrete and steel boilers.