Search Results for metal powder handling

During metal powder production, powder and/or dust handling, compaction, and part finishing operations, many safety and environmental risks exist. This article is a detailed account of the types of safety hazards that can exist and the issues that occur during metal powder handling, as well as recommendations and strategies that can be employed to both prevent and protect against damaging effects from powder exposure, fire and/or explosions, or environmental impact events.

This article provides an overview of the concepts of environmental, health, and safety (EH&S) risk incidents, then discusses these concepts relative to additive manufacturing (AM): the multiple intrants, process parameters, and equipment, as well as the resulting products and wastes. The article discusses additive manufacturing hazards, which are broken down into material hazards, equipment/process hazards, and facility hazards. The environmental impact of AM and the development of EH&S standards for AM also are covered in the article.

Health and safety are critically important issues, and there are numerous aspects of the production and use of metal powders that may entail exposure to hazardous conditions. This article provides a discussion on the issues associated with the safe production and handling of metal powders and the safe operation of continuous mesh belt sintering furnaces with combustible atmospheres. It also provides a comprehensive high-level overview of the safety-related issues and concerns related to the use of compacting presses in the manufacturing sector.

This article provides information on the microstructure of powder metal alloys and the special handling requirements of porous materials. It covers selection, sectioning, mounting, grinding, and polishing, and describes procedures, such as washing, liquid removal, and impregnation, meant to preserve pore structures and keep them open for analysis. The article compares and contrasts the microstructures of nearly 50 powder metal alloys, using them to illustrate the effect of consolidation and compaction methods as well as particle size, composition, and shape. It discusses imaging equipment and techniques and provides data on etchants and etching procedures.

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.

Consolidation and shaping of grade powders is carried out using several methods, depending on the size, complexity, shape, and quantity of parts required. This article details the powder consolidation methods of carbide powders: uniaxial pressing, cold isostatic pressing, extrusion, green machining, and injection molding.

This article describes the methods for determining the flow rate of metal powders. It examines the factors affecting flow rate, apparent density, and angle of repose of metal powders. The article reviews the frictional properties, cohesive strength, frictional properties, tap density, and compressibility of metal powders. It explains the mechanisms of powder segregation. The article provides information on green strength and springback value of rectangular test bar. It concludes with a discussion on the chemical composition of metal powders.

The hazards associated with thermal spray deposition processes include ultraviolet and infrared radiation; acoustical noise; and by-product production in the forms of nitrous oxides, ozone, fumes, and dust. The most important consideration in health and safety is to use the engineered controls of hazards. This article provides a brief description of the spray booth, the most commonly used engineering tool to separate the operator from the thermal spray process and confine the associated hazards. It also presents guidelines on the proper and safe handling of industrial gases and ventilation and heat exhaust. The article provides information on the personal protective equipment for eyes and skin from radiation, and ears from noise. It also discusses other potential safety hazards associated with thermal spraying, namely, magnetic fields and infrasound.

This article discusses the production of aluminum and aluminum alloy powders with emphasis on the gas atomization method and the atomizing nozzle. It illustrates the particle formation mechanism and details the requisites for particle size distribution, control, and morphology. The article presents information on the mean oxide thickness formed on atomized powders. It also describes the mechanical and physical properties of aluminum and aluminum alloy powders, as well as their applications.

The primary market for metal powder is the production of powder metallurgy (PM) parts, which are dominated primarily by iron and copper powders. This article reviews the chemical and pyrotechnics applications of ferrous and nonferrous powders. It describes the characteristics of iron powder used in oxygen scavengers and chemical reactive warmers and heaters. Metal powders used as fuels in solid propellants, pyrotechnic devices, explosives, and similar applications are reviewed. Atomized aluminum, magnesium, tungsten, and zirconium powders are also discussed.

This article focuses on direct extrusion processing where metal powders undergo plastic deformation, usually at an elevated temperature, to produce a densified and elongated form having structural integrity. It provides information on the basic powder extrusion processes and the mechanics of extrusion. The article also examines specific extrusion practices for the production of wrought material from powder stock and provides examples of materials processed by powder extrusion.

This article uses metal and alloy powders as examples to briefly discuss how to perform the characterization of powders. It begins by reviewing some of the techniques involved in the sampling of powders to ensure accurate characterization. This is followed by a discussion on the important properties to characterize powders, namely the particle size, surface area, density, porosity, particle hardness, compressibility, green strength, and flowability. For characterization of powders, both individual particles and bulk powders are used to evaluate their physical and chemical properties. The article also discusses the important characteristics and compositions of powder as well as impurities that directly affect powder properties. It ends with a description of the ignition and dust-explosion characteristics of organic and metal powders.

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 several factors, which help in determining the compressibility of metal powders: particle shape, density, composition, hardness, particle size, lubrication, and compacting. It discusses the uses of annealing metal powders and describes compressibility testing of the powders. The article details green strength and its mechanism and the variables affecting the strength. It also discusses two test methods for determining the green strength: the Rattler test and the transverse bend test.

Significant expansion of thermal spray technology occurred with the invention of plasma spray, detonation gun, and high-velocity oxyfuel (HVOF) deposition technologies. This article provides a brief history of the major initiating inventions/developments of thermal spray processes. It provides information on feedstock materials developed for specific thermal spray processes.

Aluminum powders can be formed into components by several competing technologies, including powder metallurgy (PM), metal injection molding, powder forging, and additive manufacturing. This article explores PM methodologies that are being exploited to manufacture such components. It reviews emerging technologies that promise to offer exciting ways to produce aluminum parts. The article discusses the various steps involved in PM, such as powder production, compaction, sintering, repressing, and heat treatment. It provides information on aluminum production statistics and the wear-resistance applications of PM.

Powder metallurgy (PM) stainless steels, as with conventional PM steels, are often used in the as-sintered condition. In addition to cost considerations, minimization of postsinter handling and secondary operations is also preferred because it reduces the potential for contamination of the parts with particulates and residues, which can result in the appearance of surface rust. This article provides information on various secondary operations, including tumbling, re-pressing, resin impregnation, annealing or heat treating, brazing, machining, and welding. It describes those aspects relating to welding of PM stainless steels, specifically, the effects of density, residual porosity, and sintered chemistry on weldability. Further, the article investigates the influence the sintering atmosphere has on machinability, as well as differences created by the presence of residual porosity.

This article focuses on binder-jetting technologies in additive manufacturing (AM) that produce metal artifacts either directly or indirectly. The intent is to focus on the most strategic and widespread uses of the binder jetting technology and review some of the challenges and opportunities for that technology. The discussion includes a historical overview and covers the major steps involved and the advantages of using the binder jetting process. The major steps of the process covered include printing, curing, de-powdering, and sintering.

This article describes the six fundamental factors that decide a tool's performance. These are mechanical design, grade of tool steel, machining procedure, heat treatment, grinding, and handling. A deficiency in any one of the factors can lead to a tool and die failure. The article presents a seven-step procedure to be followed when looking for the reason for a failure. A review of the results of the seven-point investigation may lead directly to the source of failure or narrow the field of investigation to permit the use of special tests.