Mechanical testing is an evaluative tool used by the failure analyst to collect data regarding the macro- and micromechanical properties of the materials being examined. This article provides information on a few important considerations regarding mechanical testing that the failure analyst must keep in mind. These considerations include the test location and orientation, the use of raw material certifications, the certifications potentially not representing the hardware, and the determination of valid test results. The article introduces the concepts of various mechanical testing techniques and discusses the advantages and limitations of each technique when used in failure analysis. The focus is on various types of static load testing, hardness testing, and impact testing. The testing types covered include uniaxial tension testing, uniaxial compression testing, bend testing, hardness testing, macroindentation hardness, microindentation hardness, and the impact toughness test.

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 concepts of quality control (QC) and quality assurance (QA), and clarifies the differences and similarities in the roles and responsibilities of QC and QA personnel. It describes the inspection procedures used to verify proper surface preparation and installation of the protective coating/lining system. Prior to beginning surface-preparation operations, many specifications will require a presurface-preparation inspection to verify the correction of fabrication defects and removal of surface contamination such as grease, oil, cutting compounds, lubricants, and chemical contaminants. When inspecting concrete prior to coating installation, three areas of concern exist: surface roughness, moisture content in concrete, and acidity/alkalinity of the surface. The article provides information on the industry standards for assessing surface cleanliness. It details postcoating application quality requirements, including measuring of dry-film thickness, assessing intercoat cleanliness, verifying minimum and maximum recoat intervals, performing holiday/pinhole detection, conducting cure/hardness testing, and assessing adhesion of the applied coating system.

Elastomers belong to a group of materials known as polymers that acquire their properties and strength from their molecular weight, chain entanglements, and crystalline regions. This article focuses on the use of elastomers as seals and describes its performance capabilities from the point of a sealant. The important technical concepts that define the performance capabilities of the elastomeric part include polymer architecture (molecular building blocks), compounding (the ingredients within the polymer), and vulcanization of the elastomer shape. The article discusses the aggressiveness of the chemical environment, temperature, and minor constituents in the environment and in the material itself that affect the chemical resistance of the elastomer. It provides a discussion on performance evaluation methods, namely, immersion testing and application specific testing that are determined using ISO and ASTM standards. The article concludes with information on elastomer failure modes and failure analysis.

Wear of metals occurs by plastic displacement of surface and near-surface material, and by detachment of particles that form wear debris. This article presents a table that contains the classification of wear. It describes the testing and evaluation of wear and talks about the abrasive wear, lubrication and lubricated wear, and selection of steels for wear resistance. The article discusses the effect of alloying elements, composition, and mechanical properties of carbon and low-alloy steels at elevated temperatures. It talks about the fatigue resistance characteristics of steels, and describes the forms of embrittlement associated with carbon and low-alloy steels. The article provides information on the effect of composition, manufacturing practices, and microstructure on notch toughness of steels. Finally, it explains the effects of alloy elements, inclusion content, microstructure and heat treatment on fracture toughness of steels.

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 is a comprehensive collection of engineering tables providing information on the mechanical properties of and the techniques for processing and characterizing polymeric materials, such as thermosets, thermoset-matrix unidirectional advanced composites, and unreinforced and carbon-and glass-reinforced engineering thermoplastics. Values are also provided for chemical resistance ratings for selected plastics and metals, and hardness of selected elastomers.

This article describes the use of conventional machining techniques, laser cutting and water-jet cutting for producing finished composite parts. It explains two representative polymer-matrix composites--graphite and aramid composites--and discusses the machining and drilling problems such as delamination and fiber or resin pullout. The article describes machining and drilling techniques and the necessary tools and cutting parameters. It presents a description of laser cutting. The article also provides information on the advantages, disadvantages, cutting characteristics, and applications of water-jet cutting and abrasive water-jet cutting.

Blow molding has emerged as a commercially viable process for manufacturing parts for nonpackaging/industrial markets. This article discusses the machinery required, processing methods, mold types, process parameters, part designs and material distribution of blow molding. It provides an outline of the parison programming system equipped with blow molders to control the parison thickness. The article describes factors that are usually considered to minimize material distribution problems, namely, design, material selection, process control, part performance, and cost.

This article discusses the properties, chemical structures, and applications of different types of elastomers grouped based on their resistance to aging (oxidative degradation), solvents, and temperature. These include butadiene rubber, natural rubber, isoprene rubber, chloroprene rubber, styrene-butadiene rubber, aerylonitrile-butadiene (nitrile) rubber, isobutylene-isoprene (butyl) rubber, ethylene-propylene (-diene) rubber, and silicone rubber. The article also provides an outline of the concerns related to the processing stages of rubbers or elastomers, including mixing or compounding, shaping, and vulcanizing or crosslinking.

Polyvinylidene fluoride (PVDF)-based coatings are typically used in outdoor applications that require exceptionally high performance and excellent long-term exterior durability with little maintenance. This article provides a background of three fluoropolymers most commonly used for coatings, namely, PVDF, polyvinyl fluoride, and polytetrafluoroethylene. It focuses on general properties, polymerization, resin types, coating formulation, technology of organic coatings, coating properties, and health and related safety considerations of PVDF. The article describes the application and typical end uses of PVDF-based coatings and the opportunities for improvement in PVDF-based coatings as with all organic coatings.

This article is an informative primer on sealants and the role they play in engineered assemblies. It discusses the physical, thermal, chemical, and electrical properties of sealant materials and the various forms in which they are applied, including liquids, pastes, and extruded tapes. It also describes classifications and types, comparing and contrasting sealants made from oil-based caulks, asphalts, coal tar resins, latex acrylic sealants, polyvinyl acetate caulks, solvent acrylics, butyl sealants, polysulfides, polyurethanes, modified silicones, anaerobics, vinyl plastisols, and polypropylenes. In addition, the article provides practical design insight, addressing application requirements, seal configurations, and joint stresses. It concludes with a brief discussion on the use of sealants in aerospace, automotive, electrical, and construction applications.

This article discusses surface engineering of nonferrous metals including aluminum and aluminum alloys, copper and copper alloys, magnesium alloys, nickel and nickel alloys, titanium and titanium alloys, zirconium and hafnium, zinc alloys, and refractory metals and alloys. It describes various techniques to improve functional surface properties and enhance the appearance of product forms. The article discusses various cleaning and finishing techniques such as abrasive blast cleaning, polishing and buffing, barrel burnishing, chemical cleaning, pickling, etching and bright dipping, electrochemical cleaning, mechanical cleaning, and mass finishing. It also examines coating processes such as plating, anodizing, chemical conversion coating, and thermal spray, and concludes with a discussion on oxidation-resistant coatings for refractory metals.

Aluminum or aluminum alloy products have various types of finishes applied to their surfaces to enhance appearance or improve functional properties. This article discusses the procedures, considerations, and applications of various methods employed in the cleaning, finishing, and coating of aluminum. These include abrasive blast cleaning, barrel finishing, polishing, buffing, satin finishing, chemical cleaning, chemical brightening, electrolytic brightening, chemical etching, alkaline etching, acid etching, chemical conversion coating, electroplating, immersion plating, electroless plating, porcelain enameling, and shot peening.

This article describes the presses that are mechanically or hydraulically powered and used for producing sheet, strip, and plate from sheet metal. It also presents the JIC standards for presses, compares the presses based on power source, details the selection criteria and provides information on the various drive systems and the auxiliary equipment. It describes the selection of die materials and lubricants for sheet metal forming and provides information on the lubrication mechanisms and selection with a list of lubricant types for forming of specific sheet materials of ferrous or nonferrous metals. The article reviews the various types of forming processes such as blanking, piercing, fine-edge blanking, press bending, press forming, forming by multiple-slide machines, deep drawing, stretch forming, spinning, rubber-pad forming, three-roll forming, contour roll forming, drop hammer forming, explosive forming, electromagnetic forming, and superplastic forming.

Advanced thermoplastics are stiff, moldable plastics that compete with traditional engineering thermoplastics and thermosets owing to their good tensile, compressive, impact, and shear strength, electrical properties, and corrosion resistance. This article discusses commercial forms, family characteristics, properties and applications of the following advanced thermoplastics: homopolymer and copolymer acetals, fluoropolymers, ionomers, polyamides, polyamide-imides, polyarylates, polyketones, polyaryl sulfones, polybutylene terephthalates, polycarbonates, polyether-imides, polyether sulfones, polyethylene terephthalates, thermoplastic polyimides, liquid crystal polymers, polyphenylene ether blends, polyphenylene sulfides, and polysulfones.

Many applications of ceramics and glasses require them to be joined to each other or to other materials such as metals. This article focuses on ceramic joining technologies, including glass-metal sealing, glass-ceramic/metal joining, ceramic-metal joining, ceramic-ceramic joining, and the more advanced joining of nonoxide ceramics. It also discusses metallizing, brazing, diffusion bonding, and chemical bonding.