In this article, an in-depth overview of petroleum quenching oils is provided, including oil composition, use, mechanism of the oil quenching processes, oil degradation, toxicology and safety, and quenching bath maintenance.

This article provides a detailed discussion on nanoindentation hardness, high-strain-rate behavior and strain-rate sensitivity, and corrosion response of additively manufactured (AM) metals. It summarizes the most commonly used AM alloys for applications in harsh environments and their respective corrosion responses in various service environments. It also provides several case studies on location-dependent properties, microstructural evolution, and indentation strain-rate sensitivity of various additively manufactured alloys.

This introductory article describes the various aspects of chemical structure that are important to an understanding of polymer properties and thus their eventual effect on the end-use performance of engineering plastics. The polymers covered include hydrocarbon polymers, carbon-chain polymers, heterochain polymers, and polymers containing aromatic rings. The article also includes some general information on the classification and naming of polymers and plastics. The most important properties of polymers, namely, thermal, mechanical, chemical, electrical, and optical properties, and the most significant influences of structure on those properties are then discussed. A variety of engineering thermoplastics, including some that are regarded as high-performance thermoplastics, are covered in this article. In addition, a few examples of commodity thermoplastics and biodegradable thermoplastics are presented for comparison. Finally, the properties and applications of six common thermosets are briefly considered.

This article provides practical information and data on property development in engineering plastics. It discusses the effects of composition on submolecular and higher-order structure and the influence of plasticizers, additives, and blowing agents. It examines stress-strain curves corresponding to soft-and-weak, soft-and-tough, hard-and-brittle, and hard-and-tough plastics and temperature-modulus plots representative of polymers with different degrees of crystallinity, cross-linking, and polarity. It explains how viscosity varies with shear rate in polymer melts and how processes align with various regions of the viscosity curve. It discusses the concept of shear sensitivity, the nature of viscoelastic properties, and the electrical, chemical, and optical properties of different plastics. It also reviews plastic processing operations, including extrusion, injection molding, and thermoforming, and addresses related considerations such as melt viscosity and melt strength, crystallization, orientation, die swell, melt fracture, shrinkage, molded-in stress, and polymer degradation.

This article discusses the thermal properties of engineering plastics and elastomers with respect to chemical composition, chain configuration, and base polymer conformation as determined by thermal analysis. It describes the processing of base polymers with or without additives and their response to chemical, physical, and mechanical stresses whether as an unfilled, shaped article or as a component of a composite structure. It summarizes the basic thermal properties of thermoplastics and thermosets, including thermal conductivity, temperature resistance, thermal expansion, specific heat, and glass transition temperature. It also provides information on polyimide and bismaleimide resin systems. Representative examples of different types of engineering thermoplastics are discussed primarily in terms of structure and thermal properties.

A material is flammable if it is subject to easy ignition and rapidly flaming combustion. The plastics that are most widely used are the least expensive and tend to be the most flammable. This article describes the two basic approaches to improving the fire resistance of a polymeric material: modifying or substituting the basic polymer so that exposure to heat and oxygen will not produce rapid combustion, and using flame-retardant additives. It also provides an overview of the burning process and presents two flammability test methods.

This article provides an overview of the physics and math associated with moisture-related failures in plastic components. It develops key equations, showing how they are used to analyze the causes and effects of water uptake, diffusion, and moisture concentration in polymeric materials and resins. It explains how absorbed moisture affects a wide range of properties, including glass transition temperature, flexural and shear modulus,creep, stress relaxation, swelling, tensile and yield strength, and fatigue cracking. It provides relevant data on common polymers, resins, and fiber-resin composites.

This article describes the processes involved in photochemical aging and weathering of polymeric materials. It explains how solar radiation, especially in the UV range, combines with atmospheric oxygen, driving photooxidation and the development of unstable photoproducts that cause various types of damage when they decompose, including the scission of carbon bonds and polymer chains. The article illustrates some of the degradation reactions that occur in different polymers and presents an overview of the strategies used to prevent such reactions or otherwise mitigate their effects.

This article focuses on a study that was performed to understand the effects of powder attributes; process parameters; and hot isostatic pressing (HIP) treatment on the densification, mechanical and corrosion properties, and microstructures of 17-4 PH stainless steel gas- and water-atomized laser-powder bed fusion (LPBF) parts at various energy densities. The results from the study showed the strong dependence of densification, mechanical properties, and microstructures on temperature, pressure, and time during the HIP cycle. The density, ultimate tensile strength, hardness and yield strength of gas and water-atomized LPBF parts increased due to HIP treatment and were higher than as-printed properties. The results also confirmed superior corrosion performance of the HIP treated LPBF parts.

This article endeavors to familiarize the reader with a selection of different ionization designs and instrument components to provide knowledge for sorting the various analytical strategies in the field of solid analysis by mass spectrometry (MS). It begins with a description of the general principles of MS. This is followed by sections providing a basic understanding of instrumentation and discussing the operating requirements as well as practical considerations related to solid sample analysis by MS. Instrumentation discussed include the triple quadrupole mass spectrometer and the time-of-flight mass spectrometer. Inductively coupled plasma and thermal ionization MS provide atomic information, and direct analysis in real-time and matrix-assisted laser-desorption ionization MS are used to analyze molecular compositions. The article describes various factors pertinent to ionization methods, namely glow discharge mass spectrometry and secondary ion mass spectrometry. It concludes with a section on various examples of applications and interpretation of MS for various materials.

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.

This article focuses on the principles and applications of X-ray photoelectron spectroscopy (XPS) for the analysis of elemental and chemical composition. The discussion covers the nomenclature, instruments, and specimen preparation process of XPS. Some of the factors pertinent to the calibration of materials for accurate measurements using XPS are provided, along with some aspects of the accuracy in quantitative analysis by XPS. In addition, the article presents examples of how XPS data can be used to solve problems with surface interactions.

This datasheet provides information on key alloy metallurgy, fabrication characteristics, processing effects on physical and mechanical properties, and applications of Al-Cu-Si general-purpose casting alloy 208.0 (aluminum alloy 2xxx).

Alloy 7040 is a variation of 7050, where Zr additions prevent recrystallization of hot-worked products during solution heat treatment without the quench sensitivity from additions of Cr. This datasheet provides information on composition limits and fabrication characteristics of aluminum alloys 7040 and 7140 and processing effects on mechanical properties of aluminum alloy 7040-T7651 high-strength plate.

This datasheet provides information on composition limits, mill product specifications, fabrication characteristics, processing effects on physical and mechanical properties, and applications of high-strength Al-Mg-Mn-Cr alloy 5456.

Alloys 2297 and 2397 were developed for thick plate integral structures. This datasheet provides information on composition limits of these 2xxx series alloys and processing effects on mechanical properties of alloy 2297-T87 plate. A figure provides a performance comparison of 2297-T87 and 2124-T851 plates.

This article illustrates the relationships among commonly used 2xxx series alloys. It contains tables that list values for composition limits of aluminum-lithium alloys, and aerospace alloys and their temper conditions according to primary design requirements.