Search Results for molybdenum disulfide

This article lists functions of lubricants common to the majority of applications and processes. It discusses the lubricant candidates widely used in forging: conversion coatings with soaps (stearate compounds) and molybdenum disulfide for cold forging; oil-based thick, film oil or polymerbased lubricants and molybdenum disulfide for warm application; graphite suspensions in oil or water for hot forging steels; and glass films for titanium and superalloys hot forgings. The article describes the applications of lubricants in warm extrusion and forging, hot forging of steel, hot forging of aluminum, isothermal and hot die forging, and the extrusion of steel.

Machinability is more important in extending the applications of powder metallurgy (PM). This article provides an overview of the machining process and machinability measurement of PM steels. It discusses various approaches to improve machinability, including the closure of porosity, green machining, presintering, microcleanliness improvement, free-machining additives, microstructure modification, and improvements in tool materials. The effects of free-machining agents on machinability and the sintered properties of PM steels are also reviewed.

This article describes the formability and surface contamination of the refractory metals such as niobium, tantalum, molybdenum, tungsten, and titanium-zirconium-molybdenum alloys. It reviews the factors that affect mechanical properties and formability during rolling and heat treatment. The effect of temperature on the formability of refractory metals is discussed. The article provides a description of the forming methods of sheet and preformed blanks using refractory metals. It also discusses the types of lubricants, including oils, soaps, waxes, silicones, graphite, and molybdenum disulphide, used in the forming of refractory metals.

This article focuses on the forging characteristics of different types of refractory metals and alloys, namely, niobium and niobium alloys, molybdenum and molybdenum alloys, tantalum and tantalum alloys, and tungsten and tungsten alloys.

This article provides an overview of the interfacial interactions with a lubricant film between a die and a metal, lubricant mechanisms, chemistry, qualification testing, application methods, and property test methods. It focuses on sheet metal-forming operations, although the discussions are relevant to metal-forming operations in general. The article also deals with lubricant selection as influenced by the metal to be formed and particular sheet-metal forming operations. The article also discusses some aspects of microbiology and toxicity in lubricants.

Transition metal dichalcogenides (TMD) are solid lubricant materials, specifically, intrinsic solid lubricants, whose crystal structure facilitates interfacial sliding/shear to achieve low friction and wear in sliding contacts and low torque in rolling contacts. This article provides information on sliding friction and wear behavior of unbonded, bonded, and vapor-deposited pure and composite MoS 2 and WS 2 coatings. It discusses the rolling-torque behavior and applications of vapor-deposited pure and composite MoS 2 and WS 2 coatings. The article concludes with information on various forms of TMD lubrication, namely, oils, greases, microparticle and nanoparticle additives.

Characteristics of stainless steel that affect its formability include yield strength, tensile strength, and ductility, in addition to the effect of work hardening on these properties. This article discusses the forming process of stainless steel, heat-resistant alloys and refractory metals, detailing the major aspects of forming, including formability, lubrication, and forming methods and tools. The effect of factors such as alloy condition, cold reduction, forming direction (in the case of heat-resistant alloys) and temperature (in the case of refractory metals) on formability is also discussed.

This article discusses the presses, auxiliary equipment, and dies used in the blanking and piercing of commonly used magnetically soft materials, namely, low-carbon electrical steels and oriented and nonoriented silicon electrical steels. It describes the effect of stock thickness and work metal composition and condition on blanking and piercing. The article provides an overview of the influence of burr height on stacking factors and presents a discussion on the lubrication and core plating of electrical steels that ease the process.

This article discusses the functions of lubricants to prevent premature failure of rolling element bearings and the advantages of fluid lubrication. It describes the composition of refined mineral oil for rolling bearing applications. The article reviews the types and properties of nonpetroleum oils, such as polyglycols, phosphate esters, silicone fluids, dibasic acid esters, and fluorinated polyethers. It discusses the properties of greases, including grease speed limits, grease composition, relubrication intervals, corrosion prevention behavior, and grease compatibility. The article concludes with a discussion on polymeric lubricants and solid lubricants.

This article describes friction force as a function of normal force in dry forming. It focuses on metal forming operations usually classified as cold working and hot working based on metallurgical considerations. The article discusses surface flattening and roughening of workpiece asperities in metal forming. It presents advanced tribology models and results for friction in isothermal forging operations in which the tooling is maintained at a temperature close to that of the workpiece. The article provides information on heat transfer models. It discusses the effect of wear in manufacturing processes. The article concludes with information on the main categories of tool and die materials used for a variety of manufacturing application.

This article reviews cleaning and finishing operations that have proven to be effective on titanium, its alloys, and semi-fabricated titanium products. It explains how to remove scale, tarnish films, grease, and other soils and how to achieve required finishes and/or improve wear and oxidation resistance through the use of polishing, buffing, and wire brushing operations. The article also covers a wide range of surface modification and coating processes, including ion implantation, diffusion, chemical and physical vapor deposition, plating, anodizing, and chemical conversion coatings as well as sprayed and sol-gel coatings and laser and electron-beam treatments.

This article provides an overview of the compaction of metal powder in a rigid die and reviews the compaction characteristics of stainless steel powders, including green density, compressibility, green strength, apparent density, flow rate, and sintered density. It describes the influence of compaction characteristics of stainless steel powders in tool materials selection, lubrication, annealing, double pressing/double sintering, and warm compaction.

This article provides an overview of surface contaminants that may affect the heat treatment processes and end-product quality. It presents information on the chemicals used to clean different surface contaminants of steels. The article discusses three types of cleaning methods, namely, mechanical, chemical, and electrochemical and their effectiveness and applicability. The mechanical cleaning methods include grinding, brushing, steam or flame jet cleaning, abrasive blasting, and tumbling. Solvent cleaning, emulsion cleaning, alkaline cleaning, acid cleaning, pickling, and descaling are chemical cleaning methods. The electrochemical cleaning methods include electropolishing, electrolytic alkaline cleaning, and electrolytic pickling. The article provides information on cleanliness measurement methods such as qualitative tests and quantitative tests to ensure product quality. Health hazards that may be associated with each cleaning method and the general control measures to be used for each hazard are tabulated.

Electrical contacts are metal devices that make and break electrical circuits. This article describes the property requirements such as electrical conductivity, mechanical properties, chemical properties, fabrication properties, and thermal properties of make-break arcing contacts. The article also focuses on brush contact materials and their interdependence factors for sliding contacts. In addition, the article discusses the properties, manufacturing methods, and applications of electrical contact materials, including wrought materials such as copper metals, silver metals, gold metals, precious metal overlays, tungsten, molybdenum, and aluminum, and composite materials. It concludes by discussing the composite manufacturing methods such as infiltration, press-sinter, press-sinter-repress process, press-sinter-extrude process, internal oxidation, and preoxidized-press-sinter-extrude process, and coprecipitation.

Refractory metals are extracted from ore concentrates or scrap, processed into intermediate chemicals, and then reduced to metal, usually in powder form. This article discusses the raw materials needed and the processing steps for producing pure and alloyed refractory metal powders. The effects of processing conditions on the physical and chemical properties of tungsten, molybdenum, tantalum, niobium, and rhenium powders are reviewed.

This article describes the presses that are mechanically or hydraulically powered and used for producing sheet, strip, and plate from sheet metal. It also presents the JIC standards for presses, compares the presses based on power source, details the selection criteria and provides information on the various drive systems and the auxiliary equipment. It describes the selection of die materials and lubricants for sheet metal forming and provides information on the lubrication mechanisms and selection with a list of lubricant types for forming of specific sheet materials of ferrous or nonferrous metals. The article reviews the various types of forming processes such as blanking, piercing, fine-edge blanking, press bending, press forming, forming by multiple-slide machines, deep drawing, stretch forming, spinning, rubber-pad forming, three-roll forming, contour roll forming, drop hammer forming, explosive forming, electromagnetic forming, and superplastic forming.

This article briefly reviews the subject of copper-base powder-metallurgy (P/M) products in terms of powder production methods (atomization, oxide reduction, electrolysis, and hydrometallurgy) and the product properties/consolidation practices of the major applications. Of the four major methods for making copper and copper alloy powders, atomization and oxide reduction are presently practiced on a large scale in North America. The article provides information on the mechanism, production, properties, composition and applications of different types of copper-base P/M products, including self-lubricating sintered bearings, structural parts, oxide-dispersion-strengthened copper, sintered metal friction materials, and porous filters.

This article addresses surface cleaning, finishing, and coating operations that have proven to be effective for molybdenum, tungsten, tantalum, and niobium. It describes standard procedures for abrasive blasting, molten caustic processing, acid cleaning, pickling, and solvent and electrolytic cleaning as well as mechanical grinding and finishing. The article also provides information on common plating and coating methods, including electroplating, anodizing, and oxidation-resistant coatings.

This article describes different types of titanium alloys, including alloy Ti-6Al-4V, alpha and near-alpha alloys, and alpha-beta alloys. It explains the formability of titanium alloys with an emphasis on the Bauschinger effect. The article provides information on the tool materials and lubricants used in the forming process. It provides information on the cold and hot forming, superplastic forming, and combination of superplastic forming/diffusion bonding. The article discusses the various forming processes of these titanium alloys, including press-brake forming, power (shear) spinning, rubber-pad forming, stretch forming, contour roll forming, creep forming, vacuum forming, drop hammer forming, joggling, and explosive forming.