Wrought copper and copper alloys are produced in various mill-product forms for a variety of applications due to their high electrical conductivity, corrosion resistance, ease of fabrication, and good heat-transfer properties. This article describes the manufacturing processes used to produce wrought copper and copper alloys in the form of sheet and strip products, tubular products, and wire and cable. Common processes include melting, casting, hot and cold rolling, milling or scalping, annealing, cleaning, slitting, cutting, and leveling. In addition, the article discusses stress-relaxation characteristics of copper alloys.

Copper and copper alloys are used extensively in structural applications in which they are subject to moderately elevated temperatures. At relatively low operating temperatures, these alloys can undergo thermal softening or stress relaxation, which can lead to service failures. This article is a collection of curves and tables that present data on thermal softening and stress-relaxation in copper and copper alloys. Thermal softening occurs over extended periods at temperatures lower than those inducing recrystallization in commercial heat treatments. Stress relaxation occurs because of the transformation of elastic strain in the material to plastic, or permanent strain.

Cast and wrought coppers can be strengthened by cold working. This article provides information on minor alloying elements, such as beryllium, silicon, nickel, tin, zinc, and chromium, used to strengthen copper. It details annealing and recrystallization and grain growth characteristics of copper. The article also discusses the tensile-stress-relaxation behavior of selected types of copper wires.

This article discusses stress relaxation testing on metallic materials, as covered by ASTM E 328. It reviews the two types of stress relaxation tests performed in tension, long-term and accelerated testing. The article illustrates load characteristics and data representation for stress relaxation testing used for the most convenient and common uniaxial tensile test. It concludes with information on compression testing, bend testing, torsion testing, and tests on springs.

The principal types of elevated-temperature mechanical failure are creep and stress rupture, stress relaxation, low- and high-cycle fatigue, thermal fatigue, tension overload, and combinations of these, as modified by environment. This article briefly reviews the applied aspects of creep-related failures, where the mechanical strength of a material becomes limited by creep rather than by its elastic limit. The majority of information provided is applicable to metallic materials, and only general information regarding creep-related failures of polymeric materials is given. The article also reviews various factors related to creep behavior and associated failures of materials used in high-temperature applications. The complex effects of creep-fatigue interaction, microstructural changes during classical creep, and nondestructive creep damage assessment of metallic materials are also discussed. The article describes the fracture characteristics of stress rupture. Information on various metallurgical instabilities is also provided. The article presents a description of thermal-fatigue cracks, as distinguished from creep-rupture cracks.

This article reviews the basic equipment and methods for creep and creep rupture testing. It begins with a discussion on the creep properties, including stress and temperature dependence, as well as of the extrapolation techniques that permit estimation of the long-term creep and rupture strengths of materials. The article describes the different types of equipment for determination of creep characteristics, including test stands, furnaces, and extensometers. It also discusses the different testing methods for creep rupture: constant-load testing and constant-stress testing. The article presents other testing considerations and concludes with information on stress relaxation testing.

This article discusses the deformation and viscoelastic characteristics of plastics as polymeric materials, focusing on the test methods used for the evaluation of their mechanical properties, methods available for analytically predicting the deformation response of polymers, and the effect of viscoelasticity on the test methods used. Two common ways of evaluating viscoelasticity of plastics are by means of creep experiments and dynamic mechanical experiments. Graphic or tabular analysis of test data, time-temperature superposition, and empirical correlation methods are commonly employed for analytical prediction of deformation characteristics of polymers.

This article reviews general trends in the cyclic response for representative commercial alloys to establish the spectrum of cyclic properties attainable through microstructural alteration. Individual alloy classes are examined in detail to assess the understanding of relationships between microstructure and fatigue resistance. These alloys classes include ferritic-pearlitic alloys, martensitic alloys, maraging steels, and metastable austenitic alloys. The article also discusses the role of internal defects and selective surface processing in influencing fatigue performance.

This article describes the viscoelastic behavior of plastics in their solid state only, from the standpoint of the material deforming without fracturing. The consequences of viscoelasticity on the mechanical properties of plastics are described, especially in terms of time-dependencies, as well as the dependence of the viscoelastic character of a plastic on chemical, physical, and compositional variables. By examining the viscoelastic behavior of plastics, the information obtained are then applied in situations in which it may be important to anticipate the long-term properties of a material. This includes assessing the extent of stress decay in materials that are pre-stressed, the noise and vibration transmission characteristics of a material, the amount of heat build-up in a material subjected to cyclic deformation, and the extent a material can recover from any prior deformation. Several qualitative graphs are presented, which highlights the possible differences in the viscoelastic behavior that can exist among plastics.

This article addresses the general welding characteristics common to both solid-solution-strengthened and precipitation-hardened nickel-, iron-, and cobalt alloys.

Dynamic mechanical analysis (DMA) is a powerful tool for studying the viscoelastic properties and behavior of a range of materials as a function of time, temperature, and frequency. This article describes various systems and equipment used in DMA setup and discusses the processes involved in preparation of test specimen for DMA measurements. Some factors to be considered when calibrating the DMA instrument are provided, along with a description on processes for interpreting the temperature and frequency dependence of DMA curves as well as the applications of DMA.

This article summarizes many approaches that are used to simulate relaxation of bulk residual stresses in components. It presents analytical examples to highlight the complexity of residual stress and strain distributions observed in simple geometries, with ideal material behavior and trivial loading and boundary conditions. The article discusses approximate and advanced solution techniques that can be employed in practice for simulation of residual stress relief: finite-difference method and finite-element method. It also describes advanced techniques applicable to transient creep, advanced constitutive models, and complicated stress and temperature loading histories.

Differential scanning calorimetry (DSC) is the most common thermal technique for polymer characterization. This article provides a detailed account of the various factors and processes involved in DSC. The discussion covers the equipment used, specimen preparation process, calibration requirements, data analysis, and provides examples of the applications and interpretation of DSC.

This article examines residual stresses in quenched and surface-hardened steels by focusing on its theoretical background, formation mechanisms of residual stress, effects of tempering and cryogenic cooling on residual stress, effects of residual stress on the service performance of components, and measurement, computation, and relaxation of residual stress.