The purity of aluminum is generally characterized in one of two ways, by terminology or by the Aluminum Association designation system. This article reviews the properties of pure aluminum in purities from 99.99 percent through commercial purity, 99.00 percent. The mechanical properties of aluminum are discussed in terms of tensile properties, stress-strain relationships, and creep. The article also reviews the physical properties of aluminum, such as atomic structure and nuclear properties, atomic spectrum, crystal structure, density, thermal expansion, and thermal conductivity. It discusses the chemical properties of aluminum and presents a summary tabulation of the mechanical strength, ductility, and hardness of pure aluminum.

The shielding gas used in an arc welding process has a significant influence on the overall performance of the welding system. These gases are argon, helium, oxygen, hydrogen, nitrogen, and carbon dioxide. This article discusses the shielding gas selection criteria for plasma arc welding, gas metal arc welding, and flux cored arc welding. It describes the basic properties of shielding gases, namely, dissociation, recombination, reactivity potential, oxidation potential, and gas purity. The article also provides information on the influence of the shielding gas on weld mechanical properties and self-shielded flux cored arc welding.

Laser has found its applications in cutting, drilling, and shock-peening operations of manufacturing industry because of its accurate, safe, and rapid cutting property. This article provides an account on the fundamental principles of laser cutting (thermal), drilling, and shock-peening processes of which emphasis is placed on thermal laser cutting. It details the principal set-up parameters, such as the laser beam output, nozzle design, focusing optic position and characteristics, assist gases, surface conditions, and cutting speed. A discussion on the types of gas, supply system, purity level, and flow rates of lasing and assist gases is also provided. The article also describes the metallurgies and other key material considerations that impact laser-cutting performances and includes examples of laser cutting of nonmetal materials.

The shielding gas used in a welding process has a significant influence on the overall performance of the welding system. This article discusses the basic properties of a shielding gas in terms of ionization potential, thermal conductivity, dissociation and recombination, reactivity/oxidation potential, surface tension, gas purity, and gas density. It describes the characteristics of the components of a shielding gas blend. The article discusses the selection of shielding gas for gas-metal arc welding (GMAW), gas-tungsten arc welding (GTAW), and plasma arc welding (PAW), as well as the influence of shielding gas on weld mechanical properties. It concludes with a discussion on flux-cored arc welding.

The electronic microcircuit industry has placed severe demands on metal suppliers to provide metals of the highest reproducible purity attainable as a result of the constant quest for the true values of physical and chemical properties of metals. This article describes the commonly used methods for ultrapurification of metals produced by electrolytic processes, including fractional crystallization, zone refining, vacuum melting, distillation, chemical vapor deposition, and solid state refining techniques. In addition, it describes the trace element analysis and resistance-ratio test methods used to characterize purity. Tables list the values for resistance ratios of zone-refined metals and their corresponding chemical compositions, and provide an example of the detection of impurities to concentrations in the parts per billion range, utilizing a combination of the glow discharge mass spectroscopy method and Leco combustion methods.

This article presents the following characteristics of pure metals : structure, chemical composition, mass characteristics, thermal properties, electrical properties, chemical properties, magnetic properties, optical properties, fabrication characteristics, nuclear properties, and mechanical properties.

This article discusses the major methods of elemental analysis, namely, the combustion method for carbon, hydrogen, and nitrogen; the Kjeldahl method for nitrogen; and the Schoniger flask method for other common elements. It also discusses the methods of functional group analysis for acids, alcohols, aldehydes and ketones, amines, esters, aromatic hydrocarbons, peroxides, phenols, water (Karl Fischer method), and alkenes.