This article presents a summary of the chemical fundamentals, general techniques, limitations, and applications of chemical spot testing as well as a brief overview of innovations and specialized applications. A list of selected reagents, including abbreviated instructions for preparing the reagent solution(s), for performing the spot test, and for interpreting the results, is also included. The article discusses two specialized applications of qualitative analysis, namely illicit drug identification and spacecraft drinking water quality testing. It also contains tables listing common presumptive tests for detecting anions and cations in aqueous solution.

Several qualitative, semiquantitative, and quantitative tests are available to estimate and control metal cleanliness, particularly inclusion concentration of aluminum alloys. This article provides a brief description of few of the metal cleanliness assessment techniques, such as chemical analysis, pressure filter tests, electric resistivity tests, reduced-pressure test, and ultrasonic technique. It also lists the various impurities detection methods of chemical analysis and their limitations.

This article is a detailed account of the principles of electron-excited X-ray microanalysis. It begins by discussing the physical basis of electron-excited X-ray microanalysis and the advantages and limitations of energy dispersive spectrometry (EDS) and wavelength dispersive spectrometry for electron probe microanalysis. Key concepts for performing qualitative analysis and quantitative analysis by electron-excited X-ray spectrometry are then presented. Several sources that lead to measurement uncertainties in the k-ratio/matrix corrections protocol are provided, along with the significance of the raw analytical total. Sections on accuracy of the standards-based k-ratio/matrix corrections protocol with EDS and processes of analysis when severe peak overlap occurs are also included. The article provides information on low-atomic-number elements, iterative qualitative-quantitative analysis for complex compositions, and significance of standardless analysis in the EDS software. It ends with a section on the processes involved in elemental mapping for major and minor constituents.

This article provides the background of biological evaluation of medical devices. It discusses what the ISO 10993 standards require for polymeric biomaterials and presents examples of what qualitative and quantitative tests can be used to satisfy the requirements. The article describes infrared (IR) analysis and thermal analyses that are used extensively to fingerprint polymeric materials and should be a part of all polymeric biomaterials characterization programs. It also provides a discussion on the chemical characterization and risk assessment of extracts. Background information on risk assessments of extracts is also included. The four basic steps that are commonly used in the risk assessment process are discussed. These steps include hazard identification, dose-response assessment, and exposure assessment, and risk characterization.

This article focuses on wet chemical methods that have stood the test of time in laboratories around the world. It begins with a description of the appropriateness of classical wet methods. This is followed by sections on sampling procedures, basic chemical equilibria, and wet analytical chemistry. Mechanical methods and nonoxidizing acids and/or acid mixtures for dissolving solid samples for wet chemical analysis are then reviewed. Qualitative methods that are used to identify materials by wet chemical reaction are also included. The article provides information on various methods for the separation of chemical mixtures and on the types of gravimetry and titrimetry. Strategies for removing inclusions are also included to aid in their compositional understanding. The article also briefly describes the processes involved in chemical surface studies and partitioning of oxidation states. It ends by presenting some examples of the applications of classical wet methods.

Thermoelastic stress analysis (TSA) an increasingly popular infrared (IR)-based technique for measuring stress on the surface of a part subjected to time-varying loads. This article begins by providing a theoretical and historical background of thermoelastic stress analysis. It then describes infrared detectors, such as quantum detectors and thermal/nonquantum detectors, for thermoelastic stress analysis. The article discusses the theoretical aspects for producing thermoelastic stress analysis data and the applications amenable to thermoelastic stress analysis. It concludes with information on the qualitative applications of thermoelastic stress analysis.

This article provides a detailed account of X-ray spectroscopy used for elemental identification and determination. It begins with an overview of the operating principles of X-ray fluorescence (XRF) spectrometer, as well as a comparison of the operating principles of wavelength-dispersive spectrometer (WDS) and energy-dispersive spectrometer (EDS). This is followed by a discussion on the mechanism and effects of X-ray radiation, X-ray emission, and X-ray absorption. The article then discusses components used, operation, and applications of WDS and EDS. Some of the factors and processes involved in sample preparation for XRF analysis are also included. The article further provides information on the practical procedure for and the applications of WDS and EDS qualitative and quantitative analyses.

Computational fluid dynamics (CFD) is one of the tools available for understanding and predicting the performance of thermal-fluids systems. This article qualitatively describes the basic principles of CFD. The numerical methods, such as geometry description and discretization, used to solve the CFD equations are discussed. The article demonstrates the application of CFD to a few casting problems.

Stress-corrosion cracking (SCC) occurs under service conditions, which can result, often without any prior warning, in catastrophic failure. Hydrogen embrittlement is distinguished from stress-corrosion cracking generally by the interactions of the specimens with applied currents. To determine the susceptibility of alloys to SCC and hydrogen embrittlement, several types of testing are available. This article describes the constant extension testing, constant load testing, constant strain-rate testing for smooth specimens and precracked or notched specimens of SCC. It provides information on the cantilever beam test, wedge-opening load test, contoured double-cantilever beam test, three-point and four-point bend tests, rising step-load test, disk-pressure test, slow strain-rate tensile test, and potentiostatic slow strain-rate tensile test for hydrogen embrittlement.

This article discusses a number of workability tests that are especially applicable to the forging process. The primary tests for workability are those for which the stress state is well known and controlled. The article provides information on the tension test, torsion test, compression test, and bend test. It examines specialized tests including plane-strain compression test, partial-width indentation test, secondary-tension test, and ring compression test. The article explains that workability is determined by two main factors: the ability to deform without fracture and the stress state and friction conditions present in the bulk deformation process. These two factors are described and brought together in an experimental workability analysis.

This article provides an overview of common analytical tools used as part of the process of providing practical information regarding the causes of a coating problem or failure. The common analytical tools include Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy-energy dispersive X-ray spectroscopy, chromatography, and electrochemical impedance spectroscopy. Test cabinets and standard test environments for laboratory analysis are reviewed. The article describes non-standard simulation testing and case studies of simulated environments for coating failure analysis.

This article focuses on the factors that determine the extent of deformation a metal can withstand before cracking or fracture occurs. It informs that workability depends on the local conditions of stress, strain, strain rate, and temperature in combination with material factors. The article discusses the common testing techniques and process variables for workability prediction. It illustrates the simple and most widely used fracture criterion proposed by Cockcroft and Latham and provides a workability analysis using the fracture limit line. The article describes various workability tests, such as the tension test, ring compression test, plane-strain compression test, bend test, indentation test, and forgeability test. It concludes with information on the role of the finite-element modeling software used in workability analysis.

This article discusses two types of hot-tension tests, namely, the Gleeble test and conventional isothermal hot-tension test, as well as their equipment. It summarizes the data for hot ductility, strength, and hot-tension for commercial alloys. The article presents isothermal hot-tension test data, which helps to gain information on a number of material parameters and material coefficients. It details the effect of test conditions on flow behavior. The article briefly describes the detailed interpretation of data from the isothermal hot-tension test using numerical model. It also explains the cavitation mechanism and failure modes that occur during hot-tension testing.

This article describes testing and characterization methods of ceramics for chemical analysis, phase analysis, microstructural analysis, macroscopic property characterization, strength and proof testing, thermophysical property testing, and nondestructive evaluation techniques. Chemical analysis is carried out by X-ray fluorescence spectrometry, atomic absorption spectrophotometry, and plasma-emission spectrophotometry. Phase analysis is done by X-ray diffraction, spectroscopic methods, thermal analysis, and quantitative analysis. Techniques used for microstructural analysis include reflected light microscopy using polarized light, scanning electron microscopy, transmission electron microscopy, energy dispersive analysis of X-rays, and wavelength dispersive analysis of X-rays. Macroscopic property characterization involves measurement of porosity, density, and surface area. The article describes testing methods such as room and high-temperature strength test methods, proof testing, fracture toughness measurement, and hardness and wear testing. It also explains methods for determining thermal expansion, thermal conductivity, heat capacity, and emissivity of ceramics and glass and measurement of these properties as a function of temperature.

This article focuses on the testing and typical corrosion behavior of coating-substrate systems in aqueous solutions and humid aggressive atmospheres. It includes a short review of the fundamentals of corrosion, followed by a discussion of specific system behavior, electrochemical and laboratory accelerated tests, and simulated service tests. The article also contains examples of different types of corrosion damage and presents guidelines for improving corrosion resistance.

In terms of their electrical properties, plastics can be divided into thermosetting and thermoplastic materials, some of which are conductive or semiconductive. This article provides detailed information on factors that affect the property of plastics. It discusses the major test methods used to determine the following dielectric properties of plastics: dielectric breakdown voltage, dielectric strength, dielectric constant, dissipation factor, arc tracking resistance, insulation resistance, volume, and surface resistivity or conductivity. The test specifications and conditions, recommended by several U.S. and foreign testing organizations for characterizing the electrical properties of plastic materials are listed. The article describes the influence of these properties on selection of plastics for insulation application. An outline of the electromagnetic shielding and testing methods of electromagnetic interference are also provided. Designations, electrical properties, and applications of elastomers are tabulated.

Independent verification of coating system performance can be based on laboratory testing and/or field exposure. Qualification testing is a critical component to coating system selection. This article focuses on performance evaluations that are used to prequalify coating systems, namely, facility-specific, industry-specific, coating-type-specific, or a combination of these. It describes the standard laboratory tests used to generate performance data, namely, physical, compositional, chemical exposure, and application characteristics tests. The pros and cons of using manufacturer-generated data versus independently generated data are discussed. The article provides information on accelerated corrosion/weathering testing and nuclear level 1/level 2 service coatings qualification. It also describes the procedures for establishing minimum performance requirements and for determining when requalification testing may be required.

This article discusses the identifying characteristics of the forms or mechanisms of corrosion that commonly attack copper metals, as well as the most effective means of combating each. It tabulates corrosion ratings of wrought copper alloys in various corrosive media. The article describes the corrosion behavior of copper alloys in specific environments. It reviews the corrosion characteristics of copper and copper alloys in various acids, alkalis, salts, organic compounds, and gases. The article provides information on the behavior of copper alloys that is susceptible to stress-corrosion cracking in various industrial and chemical environments. It concludes with a discussion on various corrosion testing methods, including aqueous corrosion testing, dynamic corrosion tests, and stress-corrosion testing.

This article discusses the equipment design, procedures, experimental considerations, and interpretation of the torsion tests used to establish workability. It describes the application of torsion testing to obtain flow-stress data and to gage fracture-controlled workability and flow-localization-controlled failure. The article discusses the torsion test used to establish the processing parameters that are required to produce the desired microstructures.

This article discusses the several aspects of biocompatibility of polymers, including selection of a suitable polymer, specific use of a material, contact of polymer on body site, and duration of the contact. It describes factors influencing the biological response to the polymer in a biocompatibility perspective. These include raw materials, manufacturing process, cleaning and sterilization, and biodegradation and biostability. The article reviews the general testing of polymer, such as chemical, mechanical and thermal tests, to ensure that the polymer is stable and has not been adversely altered due to sterilization or processing. It concludes with a description of the guidance, provided by the regulatory authorities, on the biocompatibility testing of polymers and polymer-containing devices that can aid in selecting the right analysis.