Search Results for metal can

Prealloyed (PA) powder metallurgy is a technique where complex near-net shape titanium aircraft components are fabricated with low buy-to-fly ratios. This article describes the physical principle, mechanism, and simulation and modeling of metal can and hot isostatic pressing (HIP) processes involved in the PA powder metallurgy technique. It discusses the technical problems addressed in shape control and their solutions for understanding the advantages of powder metallurgy HIP.

A gating system is the conduit network through which liquid metal enters a mold and flows to fill the mold cavity, where the metal can then solidify to form the desired casting shape. This article discusses various desirable design considerations for the gating system. Proper design of an optimized gating system will be made easier by the application of several fundamental principles of fluid flow. The article illustrates the Bernoulli's theorem, the law of continuity, and the effect of momentum. Most casting alloys are subject to the presence of particles that can deleteriously affect the physical properties and appearance of the casting. The article lists a variety of adverse effects of the particles. Ceramic filters, when correctly applied, can be relied on to trap particles before they can enter the casting cavity. The article concludes with information on the advantages and the types of the ceramic filters.

Many nonferrous metals, including aluminum, nickel, copper, and others, are among the few materials that do not degrade or lose their chemical or physical properties in the recycling process. As a result, these metals can be recycled an infinite number of times. This article focuses on the recycling of nonferrous alloys, namely, aluminum, copper, magnesium, tin, lead, zinc, and titanium, providing details on the sources, consumption and classification of scrap, and the technological trends and developments in recycling.

Metals can react chemically with oxygen when exposed to air. Essential to an understanding of the gaseous corrosion of a metal are the crystal structure and the molar volume of the metal on which the oxide builds, both of which may affect growth stresses in the oxide. This article presents crystal structures and thermal properties of pure metals and oxides in a tabular form. The free energy of reaction, which describes the oxidation process of a pure divalent metal, is presented. The article illustrates the Richardson-Jeffes diagram, which is used in the determination of the standard Gibbs energy change of formation of oxides and the corresponding dissociation pressures of the oxides as a function of temperature. It demonstrates the Kellogg diagram which shows stability range in more complicated multioxidant systems. The article explains the determination of partial pressures of gas mixtures and partial pressures of volatile oxidation products.

This article provides the definitions of stress and strain, and describes the relationship between stress and strain by stress-strain curves and true-stress/true-strain curves. The emphasis is on understanding the factors that determine the extent of deformation a metal can withstand before cracking or fracture occurs. The article reviews the process variables that influence the degree of workability and summarizes the mathematical relationships that describe the occurrence of room-temperature ductile fracture under workability conditions. It discusses the most common situations encountered in multiaxial stress states. The construction of a processing map based on deformation mechanisms is also discussed.

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.

Fabrication of high-density heat exchangers, which have a large heat transfer area and a compact size, is best accomplished by brazing where the brazing filler metal is clad to the materials to be brazed. This article focuses on the brazing procedures involved in the fabrication of high-density heat exchangers. The brazing procedures include base metal and brazing filler metal selection; fabrication of clad brazing materials; and stamping, cleaning, and assembling of cladded parts. The article concludes with an examination of brazing parameters.

Torch brazing utilizes a fuel gas flame as a heat source for the brazing process. This article discusses the advantages, limitations, applications, and key techniques of torch brazing, and presents an overview of the equipment used.