Search Results for beryllium powder

This article briefly describes the production of beryllium powder and beryllium/beryllium oxide metal-matrix powder. It discusses fully dense consolidation methods: vacuum hot pressing, hot isostatic pressing, and cold isostatic pressing. Secondary fabrication operations of beryllium and aluminum-beryllium alloys such as extrusion, rolling, welding, joining, and machining are discussed. The article discusses quality control and provides information on the structural, optical, and high-purity grades of beryllium.

Beryllium is a metal with an unusual combination of physical and mechanical properties that make it particularly effective in optical components, precision instruments, and specialized aerospace applications. Almost all of the beryllium in use is a powder metallurgy (P/M) product. Beginning with an overview of the mining and refining processes of beryllium, this article discusses powder production and consolidation methods, beryllium grades and their designations, and the protective measures that have been enacted to reduce exposure to beryllium.

Beryllium possesses an unusual combination of physical and mechanical properties, suiting it for specialized applications where its relatively high cost can be justified. It has very low density, a moderately high melting point, high elastic modulus, and good electrical and thermal conductivity. The article describes structural, instrument, and optical grade beryllium and the corresponding compositional ranges. It also discusses processing and product forms as well as factors affecting corrosion resistance. The article concludes with a short note on health and safety considerations when handling beryllium.

This article describes the effect of temperature, composition, strain rate, and fabrication history on the results obtained in the forming of beryllium as well as the safety measures required. It provides information on the equipment, tooling, dies, and workpieces used for forming beryllium. The article discusses the role of lubrication, blank development, tool designs, and strain rates, in deep drawing. It also provides information on the tooling and applications of three-roll bending, stretch forming, and spinning.

Successful application of forging and hot pressing involves careful consideration of powder preparation and forming process parameters. This article describes the important process features for powder forging and hot pressing, along with specific applications and materials used.

This article provides a discussion on filler metal selection, brazing procedures, and brazing equipment for brazing refractory metals. These include molybdenum, tungsten, niobium, and tantalum, and reactive metals. Commercially pure and alpha titanium alloys, alpha-beta alloys, zirconium alloys, and beryllium alloys are some reactive metals discussed in the article.

The two major types of beryllium-containing alloys are copper-berylliums and nickel-berylliums. The most widely used beryllium-containing alloys are wrought copper-berylliums, which provide good strength while retaining useful levels of electrical and thermal conductivity. This article provides information on the specimen preparation procedures, macroexamination, microexamination, and microstructures of beryllium, copper-beryllium alloys, as well as nickel-beryllium alloys. It also discusses health and safety measures associated with the specimen preparation of beryllium and beryllium-containing alloys.

This article describes the four major conditions that can cause beryllium to corrode in air. These include beryllium carbide particles exposed at the surface; surface contaminated with halide, sulfate, or nitrate ions; surface contaminated with other electrolyte fluids; and atmosphere that contains halide, sulfate, or nitrate ions. The article provides information on the behavior of beryllium under the combined effects of high-purity water environment, stress and chemical environment, and high-temperature environment. The compositions of the structural grades for intentionally controlled elements and major impurities are tabulated. The article discusses the in-process problems and procedures that are common but avoidable when processing beryllium and aluminum-beryllium composites. It also describes the types of coatings used on beryllium and aluminum-beryllium. These include chemical conversion coatings, anodized coatings, plated coatings, organic coatings, and plasma-sprayed coatings.

This article discusses metal powder processing via hot isostatic pressing (HIP) and HIP cladding when metal powders are being employed in the cladding process. It traces the history of the process and details the equipment, pressing cycle, and densification mechanisms for HIP. The article describes the available process routes for fabricating products using HIP and the steps involved in the production of a part via direct HIP of encapsulated gas-atomized spherical powder. It concludes with information on the microstructures of 316L stainless steel HIP powder metallurgy valve body and a list of the mechanical properties of several powder metallurgy alloys.

This article describes the unique aspects of cold isostatic pressing (CIP) in comparison with die compaction, for powder metallurgy parts. It details the components of CIP equipment, including pressure vessels, pressure generators, and tooling material. The article reviews the part shapes and their influence in determining tap density of the filled mold. It provides a discussion on process parameters, such as dwell time, depressurization rate, evaluation of green strength and density, and thermal processing, and illustrates a process flowchart for the production of CIP parts.

This article discusses the properties of beryllium metals that require special attention when machining. It provides information on the considerations of S65 and selects 65 beryllium materials that are used for conducting tool wear studies and surface damage studies. The article highlights some of the precautions to be followed while machining beryllium metals. Information on the cutting oils, cutting tools, and speeds and feeds used in turning the beryllium are also provided. The article describes the chemical milling and photochemical machining methods that are used for etching beryllium components.