bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasonic Cleaning
Authors: Hancock Jeff
Published: December 2018

Ultrasonic cleaning involves the use of high-frequency sound waves that is above the upper range of human heating, or about 18 kHz, to remove a variety of contaminants from parts immersed in aqueous media. This article describes the process, design considerations and the equipment in ultrasonic cleaning. The components used in the generation of ultrasonic wave include piezoelectric and magnetostrictive transducers that are used in ultrasonic generators and tanks. The effects of solution type and its temperature on the effectiveness of ultrasonic cleaning are also discussed.
Pickling and Descaling
Authors: Hudson Robert M.
Published: December 2018

Pickling is the most common of several processes used to remove scale from steel surfaces. This article provides a discussion on pickling solutions, such as sulfuric and hydrochloric acid, and describes the role of inhibitors in acid pickling. It discusses the equipment and processes involved in the batch, continuous, and electrolytic pickling of carbon steel components. The article describes the effects of process variables on scale removal in sulfuric and hydrochloric acid. It concludes with a description of pickling defects, spent pickle liquor disposal, and safety practices.
Classification and Selection of Finishing Processes
Authors: Subramanian K.
Published: December 2018

This article focuses on the various technology drivers for finishing methods, namely, tolerance, consistency, surface quality, and productivity. Every finishing method may be viewed as a manufacturing system consisting of four input categories: machine tool, processing tool, work material, and operational factors. The article provides a classification of finishing as a surface generation process and addresses the characteristics of the generated surfaces and the methods used to measure them. It describes the thermomechanical interactions occurring between the processing tool and the work material in the presence of machine tool and operational factors.
Finishing Methods Using Multipoint or Random Cutting Edges
Authors: Subramanian K.
Published: December 2018

Abrasive finishing is a method where a large number of multipoint or random cutting edges are coupled with abrasive grains as a bond or matrix material for effective removal of material at smaller chip sizes. This article provides a broad overview of the various categories of abrasive products and materials, abrasive finishing processes, and the mechanisms of delivering the abrasives to the grinding or machining zone. Abrasive finishing processes, such as grinding, honing, superfinishing, microgrinding, polishing, buffing, and lapping, are discussed. The article presents a brief discussion on abrasive jet machining and ultrasonic machining. It concludes with a discussion on the four categories of factors that affect the abrasive finishing or machining: machine tool, work material, wheel selection, and operational.
Copper Plating
Authors: Weisenberger L.M. , Durkin B.J.
Published: December 2018

This article provides a detailed account of the various alkaline and acid plating baths used for electrolytic copper plating. Dilute cyanide and Rochelle cyanide baths, high-efficiency sodium and potassium cyanide baths, alkaline noncyanide copper plating baths, and alkaline copper pyrophosphate baths, are discussed. The article reviews acid plating baths such as copper sulfate bath and copper fluoborate bath. It also presents information on the surface preparation considerations, bath composition, and operating variables of copper plating as well as the equipment used.
Silver Plating
Authors: Blair Alan
Published: December 2018

Electroplated silver is used in both decorative and functional applications, such as engineering and electrical/electronic applications. This article explains the solution formulations and specifications of electrolytes used in silver plating.
Chromium Alloy Plating
Authors: Brooman Eric W.
Published: December 2018

Chromium alloys yield alloy coatings with properties that range from completely satisfactory to marginally acceptable, depending on the end use. This article provides a detailed description of plating solutions and deposition conditions and rates of chromium-iron, chromium-nickel, and chromium-iron-nickel alloys.
Mechanical Plating
Authors: Satow Arnold
Published: December 2018

Mechanical plating is a method for coating ferrous metals, copper alloys, lead, stainless steel, and certain types of castings by tumbling the parts in a mixture of glass beads, metallic dust or powder, promoter or accelerator chemicals, and water. It offers a straightforward alternative method for achieving desired mechanical and galvanic properties with an extremely low risk of hydrogen embrittlement. This article provides a detailed description of the equipment, process steps, process capabilities, applicable parts, specific characteristics, advantages, limitations, post treatments, and waste treatment of mechanical plating.
Ion Plating
Authors: Mattox Donald M.
Published: December 2018

This article begins with a list of the factors that influence the properties of physical vapor deposited films. It describes the steps involved in ion plating, namely, surface preparation, nucleation, interface formation, and film growth. The article discusses the factors influencing the properties of ion-plated films. The sources of potential applied on substrate surface, bombarding species, and depositing species are addressed. The article also provides information on the parameters that influence bombardment. It concludes with a discussion on the advantages, limitations, and applications of ion plating.
Microstructural Characterization of Coatings and Thin Films
Authors: Bull S.J.
Published: December 2018

This article describes the structure of coatings produced by plasma spraying, vapor deposition, and electrodeposition processes. The main techniques used for microstructure assessment are introduced. The relationship between the microstructure and property is also discussed. The experimental techniques for microstructural characterization include metallographic technique, X-ray diffraction, electron, microscopies, and porosimetry.
Surface Engineering of Refractory Metals and Alloys
Authors: Shields John A.
Published: December 2018

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.
Surface Engineering of Nickel and Nickel Alloys
Authors: Buckley Russell C.
Published: December 2018

This article discusses the procedures used for pickling nickel and nickel alloys. Nickel alloys can be divided into four groups: high-nickel alloys, nickel-copper alloys, nickel-chromium alloys, and nickel-iron-chromium alloys. Alloys within each composition group that has similar surface conditions are pickled in the same solutions using the same procedures. The article discusses three different surface conditions for pickling these nickel alloys: bright annealed white surface requiring removal of tarnish by flash pickling; bright annealed oxidized surface requiring removal of a layer of reduced oxide, sometimes followed by a flash pickle to brighten; and black or dark-colored surface requiring removal of adherent oxide film or scale. The article also reviews specialized pickling operations of nickel alloys and various cleaning and finishing operations, including grinding, polishing, buffing, brushing, and blasting.
Chromium Elimination in Surface Engineering
Authors: Meyers Barry , Lynn Stephen , Jang Elwin
Published: December 2018

This article focuses on alternatives to chromium in both hard chromium plating and chromate conversion coating. These include electroless nickel plating, nickel-tungsten composite electroplating, spray coating applications, and cobalt/molybdenum-base conversion coating. The article discusses the material and process substitutions that can be used to eliminate the use or emissions of chromium in industrial processes. It describes the physical characteristics of each coating, economics, environmental impacts, advantages, and disadvantages of alternative processes.
Renewable Energy Applications
Authors: Vassen Robert , Mauer Georg
Published: December 2018

The use of renewable energy has grown strongly in all end-use sectors such as power, heat, and transport. This article describes thermal spray applications that improve efficiency, lower maintenance costs, and prolong operational life in the renewable energy technologies, including wind power, hydro power, biomass and biofuels, solar energy, and fuel cells.
Protective Overlays and Coatings Used in Oil Sands
Authors: Fisher Gary , Wolfe Tonya
Published: December 2018

This article focuses on coatings and overlays adopted for use as wear- and corrosion-resistant materials in oil sand processing. It describes the most common application processes for oil sand coatings and overlays, including welding, high-velocity oxyfuel thermal spray, laser cladding, and vacuum brazing. The article provides information on the selection of overlays and materials such as chromium-carbide-base overlays and tungsten carbide metal-matrix composites.
Precoating Operations
Authors: Knapp Jim , Lemen Don
Published: December 2018

Thermal spray coating involves certain precoating operations, such as cleaning, surface preparation, and masking, that are critical to the overall quality of the coating system. In addition to these, certain other elements are considered prior to the coating, namely, customer requirements, coating function, part geometry, substrate metallurgy, structure, and thermal history. This article provides a detailed account of the various processes of surface preparation, namely, cleaning, roughening, dry abrasive grit blasting, and machining and macro roughening processes. It outlines the masking and fixturing techniques and stripping of coatings.
Feedstock Material Considerations for Thermal Spray
Authors: Sanpo Noppakun , Wang James , Berndt Christopher C.
Published: December 2018

This article discusses three types of powder-feeder systems that are commonly used throughout the thermal spray (TS) industry: gravity-based devices, rotating wheel devices, and fluidized-bed systems. It provides information on the various mechanical methods for producing powders, namely, crushing, milling, attriting, and machining. The article describes two prime methods of agglomeration. One method uses a binder by way of agglutination, while the other relies on a sintering operation. The article discusses the technology and principles of the processes that relate to thermal spraying, and offers an understanding for choosing particular feedstock materials that are classified based on the thermal spray process, material morphology, chemical nature of the material, and applications. Sieving, the most common method of separating powders into their size fractions, is also reviewed. The article also provides information on the topical areas and precautions to be undertaken to protect the operator from safety hazards.
Introduction to Applications for Thermal Spray Processing
Authors: Dorfman Mitchell R.
Published: December 2018

This article describes the process of selecting an optimum coating and material system for a specific application. It reviews critical coating functions that influence the coating selection process, and presents some application success stories. The article explores the benefits of thermal spray coatings and functions they provide. It also presents key references from various National Thermal Spray Conference, United Thermal Spray Conference, and International Thermal Spray Conference Proceedings from 2006 through 2012.
Thermal and Environmental Barrier Coatings (TBCs/EBCs) for Turbine Engines
Authors: Lima Rogerio S. , Zhu Dongming , Li Li
Published: December 2018

This article presents a summary of the current and new materials and processing techniques for thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs). Different thermal spraying and postspraying processing techniques are required to produce coatings with optimal performance. For TBCs and EBCs, the elastic modulus, mechanical strength, and toughness values are extremely important in predicting failure behavior under stress and strain conditions, mainly for modeling purposes. Sand and/or volcanic ash particles are molten in the hot zones of turbines and deposited over TBCs and EBCs. They form calcium-magnesium-aluminosilicate (CMAS) glassy deposits.
Replacement for Hard Chrome Plating on Aircraft Landing Gear
Authors: Pollack Mark
Published: December 2018

High-velocity oxyfuel (HVOF)-applied thermal spray coatings are viable candidates for replacement of hard chrome in numerous applications. HVOF thermal spraying can be used to deposit both metal alloy and cermet coatings that are dense and highly adherent to all the commonly used base metals in airframe structures. This article summarizes the results of materials and component testing. It also presents a cost/benefit analysis of HVOF WC/17Co and WC/10Co4Cr coatings on aircraft landing gear components.
Biomedical Coatings Made by Thermal Spraying for Orthopaedic Joint Applications
Authors: Zhang Zongtao
Published: December 2018

This article provides an overview of how thermal spray technology has adapted to meet the needs of the orthopaedic industry. It includes the challenges facing the development of artificial joints, substrate material selection criteria, thermal spray solutions, and clinical outcomes of thermal spray coatings. The article focuses on plasma thermal spray, which is the technique most often used to make porous titanium and hydroxyapatite (HA) coatings, such as thermal spray titanium, thermal spray HA, solution-precipitated HA, thermal spray chromium oxide, and thermal spray chromium carbide cermet coatings.
Thermal Spray Applications in the Paper Production Industry
Authors: Dorfman Mitchell R. , Sharma Atin
Published: December 2018

Thermal spray coatings, along with certain proprietary sealants, are widely used in the paper manufacturing industry for corrosion and wear resistance and to impart special surface characteristics. This article discusses the steps involved in the paper manufacturing process. Most modern papermaking machines are based on variations of the Fourdrinier machine. The article describes four operational sections of the machine: forming, press, drying, and calendar. It provides an overview of the machine components where thermal spray coatings are used, namely, digesters, blow tanks, suction roll, center press rolls, yankee dryer rolls, calendar rolls, doctor/scalping blades, and cutting equipment.
Guide to General Information Sources
Authors: Tucker R.C.
Published: December 2018

This article is a brief guide to information sources on thermal spray technology. The sources provided by ASM International and the Thermal Spray Society (TSS) include magazines and journals as well as reference books, including the ASM Handbook series, conference proceedings, newsletters, education courses, and videos. The article provides information on the specifications, standards, and quality control for coatings.
Coating Failures and Defects
Authors: Fitzsimons Brendan , Parry Trevor
Published: December 2018

Coatings, such as those applied to ships, must be resistant to abrasion, in the case of cargo hold coatings, and cyclic changes of chemicals and tank cleaning, in the case of tank linings. Failures and defects can manifest themselves at various times in the life of a coating. To determine the cause and mechanism of coating failure, all possible contributory factors must be evaluated together with a detailed history from the time of application to the time the failure was first noted. Many coating failures require further evaluation and analysis to be carried out by a qualified chemist or coating specialist, often using specialized laboratory equipment. The article presents examples of coating failures and defects, together with descriptions, probable causes, and suggested preventative measures.
Qualification Testing for Coating System Selection
Authors: Corbett William
Published: December 2018

Independent verification of coating system performance can be based on laboratory testing and/or field exposure. Qualification testing is a critical component to coating system selection. This article focuses on performance evaluations that are used to prequalify coating systems, namely, facility-specific, industry-specific, coating-type-specific, or a combination of these. It describes the standard laboratory tests used to generate performance data, namely, physical, compositional, chemical exposure, and application characteristics tests. The pros and cons of using manufacturer-generated data versus independently generated data are discussed. The article provides information on accelerated corrosion/weathering testing and nuclear level 1/level 2 service coatings qualification. It also describes the procedures for establishing minimum performance requirements and for determining when requalification testing may be required.
Acrylic Coatings
Authors: Procopio Leo J.
Published: December 2018

Acrylic coatings are one of the major generic classes of organic coatings and are prevalent in both architectural and industrial applications. This article provides information on the chemistry of acrylic polymers, the methods used in their manufacture, the relationship between structure and properties when they are formulated into coatings, and how they are being used in coatings. The main discussion points are the differences between solventborne and waterborne technologies and some of the challenges in formulating and applying waterborne acrylic coatings. The article describes the mechanism of film formation of acrylic latex polymers and its effect on final coating properties. It discusses the types of waterborne acrylic latex coatings based on chemical properties and based on applications such as primers, intermediate coats, topcoats, stains, and direct-to-substrate finishes. The article concludes with a description of the advances in the development of waterborne acrylic coatings for maintenance and protective applications.
Soluble Salts beneath Coatings
Authors: Tator Kenneth B.
Published: December 2018

Soluble salts on a surface can affect a steel substrate or coating in two principal ways: corrosion acceleration and osmotic blistering. This article provides a detailed discussion on the mechanisms for each of these deleterious effects. It describes the most detrimental anions with regard to corrosion, namely, chlorides, sulfates, and nitrates, and provides information on recognition and testing of the presence of soluble salts. The salt-measurement techniques and commercially available equipment are also described. The article provides information on research regarding tolerable levels of salts beneath coatings. The information shows that there appears to be a threshold limit to the salt contamination that a given coating/coating system can tolerate in a given environment.
Metal Powder Injection Molding of Microcomponents
Authors: Piotter Volker
Published: December 2018

This article discusses the process details of metal powder injection molding of microcomponents and the powder particle characteristics of feedstock and property requirements of binders. It reviews important characteristics to be considered in the processing steps: venting, channel diameters, binder segregation, binder degradation, feedstock supply, temperature control, demolding, debinding, and sintering. Finally, the article provides information on powder injection molding mold-filling simulation and two-component powder injection molding, offering a method for high-volume production of microcomponents made of multifunctional materials.
Pressing and Sintering of Titanium Powders
Authors: Duz Vladimir , Moxson Vladimir , Matviychuk Mykhailo , Imam M. Ashraf
Published: December 2018

Consolidation of titanium powders at room temperature may be performed by low-cost conventional powder metallurgy processes. This article provides information on various consolidation methods, namely, die pressing, direct powder rolling, and cold isostatic pressing. It also describes the sintering of blended elemental powders, high-strength titanium alloys, and porous material as well as the sintering of titanium powders by microwave heating.
Beryllium and Aluminum-Beryllium Alloys
Authors: Hashiguchi Don H. , Svilar Mark , Sayer Aaron B. , Morales Amanda L.
Published: December 2018

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.
Properties and Selection of Cemented Carbides
Authors: Koopman M. , Fang Z.Z. , Wang X. , Mehrotra Pankaj K.
Published: December 2018

Cemented carbide is, in its simplest form, a metal-matrix composite of tungsten carbide particles in a cobalt matrix. This article describes the microstructure, physical, and mechanical properties of cemented carbides. The properties discussed include thermal conductivity, magnetic properties, corrosion resistance, hardness, fracture toughness, wear resistance, and thermal shock resistance. The article concludes with information on the applications, grade classification, and selection of grades.
Food Additives
Authors: Hu Bo
Published: December 2018

The food-based approaches are considered important sustainable strategies for preventing iron deficiency. The success of a food fortification program depends on the choice of food vehicles and the choice of iron fortificants, that is, iron sources. This article discusses iron sources, namely, elemental irons and iron compounds, used as fortificants. Common elemental iron powders such as plain pure iron powders, and common iron compounds such as ferrous sulfate used in food fortifications, are reviewed. The article contains tables that list the food chemical codex requirements and the physical and chemical properties of commercial food-grade elemental irons.
Metallic Foams
Authors: Baumeister J. , Weise J.
Published: December 2018

Cellular or foam structures can be described by means of two broader cases: foams in which the pores are all connected to each other and with the environment (open-pore foams) and foams in which every single pore is completely enclosed by the matrix (closed-pore foams). This article describes the four process groups for the production of open- and closed-pore metal foams. It discusses the principles of the foaminal process with the description of various foaming agents, solidified metal foam, and geometries and derived structures of metal foams. The use of syntactic metal foam in various fields is included. The article reviews the mechanical properties of closed-pore metal foams, details the machining and joining procedures of the metal foams, and presents the applications of the metal foam.
Properties and Selection of Powder Metallurgy Titanium and Its Alloys
Authors: El-Soudani Sami M.
Published: December 2018

This article focuses on mechanical testing characterization of blended elemental powder metallurgy (PM) titanium alloys and prealloyed PM titanium alloys. It examines the tensile properties, fracture toughness, stress-corrosion threshold resistance, fatigue strength, crack propagation properties, and processing-microstructure-property relationships of these alloys. The article also reviews five considerations for powder process selection.
Infiltration of Carbide Structures
Authors: Griffo Anthony , Bell Andrew
Published: December 2018

This article provides information on the infiltration mechanism of carbide structures. It reviews the basic techniques used for metal infiltration, including dip infiltration, contact filtration, gravity feed infiltration, and external-pressure infiltration. The article highlights various applications of contact infiltration in oil, gas, and blast-hole drilling such as fixed-cutter drill bits and diamond-impregnated coring bits. It also discusses the applications of infiltrated carbide material in erosion-resistant cladding.
Ferrous Powder Metallurgy Materials
Authors: James W. Brian
Published: December 2018

This article summarizes the general classification, mechanical properties, and applications of ferrous powder metallurgy (PM) materials for parts production. It discusses four principal ferrous PM alloy types: admixed elemental alloys, diffusion alloys, prealloys, and hybrid alloys. The article reviews the benefits and disadvantages as well as the effect of processing on the properties and material microstructure of these alloys. It contains tables that list the mechanical properties of various iron-copper and copper steels.
Machinability of Powder Metallurgy Steels
Authors: Christopherson Denis
Published: December 2018

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.
Pressing and Sintering of Copper Powders
Authors: Daye Wayne K. , Pelletiers Thomas W.
Published: December 2018

Development of the properties of copper powder metallurgy parts is affected by pressing and sintering processes used in the production of components, such as contacts, carbon brushes, and friction materials. This article briefly describes the powder properties of copper and discusses the roles of lubricant and compaction dies in pressing of copper powders. It explains the structural defects that originate during the compaction process of PM parts. The article also provides information on sintering, re-pressing, and re-sintering of copper PM parts.
Joining Powder Metallurgy Steel Components
Authors: Sokolowski Peter K.
Published: December 2018

This article characterizes the physical differences between powder metallurgy (PM) and wrought or cast materials, as they apply to joining. It discusses acceptable joining procedures and techniques, including welding and brazing and solid-state methods. Information on the weldability of various PM materials is presented. The article also describes the effects of porosity on several important properties that affect the welding characteristics.
Bulk Properties of Powders
Authors: Luk Sydney H.
Published: December 2018

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.
Corrosion Resistance of Powder Metallurgy Stainless Steels
Authors: Samal Prasan K.
Published: December 2018

This article reviews various test methods used for evaluating the corrosion resistance of powder metallurgy stainless steels. These include immersion testing, salt spray testing, and electrochemical testing. The article discusses the factors that affect corrosion resistance of sintered stainless steels: compaction-related factors, sintering-related factors, and effects of alloy composition. Corrosion resistance data for sintered stainless steels is provided.
Sintering Theory and Fundamentals
Authors: Rahaman Mohamed N.
Published: December 2018

Sintering is a thermal treatment process in which a powder or a porous material, already formed into the required shape, is converted into a useful article with the requisite microstructure. Sintering can be classified as solid-state, viscous, liquid-phase, and pressure-assisted (or pressure) sintering. This article provides information on the mechanisms and theoretical analysis of sintering and focuses on the types, mechanisms, process and microstructural variables, computer simulation, stages, and fundamentals of densification and grain growth of solid-state sintering and liquid-phase sintering. It describes the models for viscous sintering and the methods used in pressure-assisted sintering, namely, uniaxial hot pressing, hot isostatic pressing, sinter forging, and spark plasma sintering.
Mechanical Properties of Powder Metallurgy Stainless Steels
Authors: Samal Prasan K.
Published: December 2018

This article describes the factors influencing the room-temperature and elevated-temperature mechanical properties of powder metallurgy (PM) stainless steels. It contains tables that list the mechanical property specifications of the Metal Powder Industries Federation (MPIF) Standard 35.
Production of Refractory Metal Powders
Authors: Wolfe Thomas A. , Enneti Ravi K. , Leonhardt Todd , Johnson John L.
Published: December 2018

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.
Pressing and Sintering of Refractory Metal Powders
Authors: Leichtfried Gerhard , Shields John A. , Johnson John L.
Published: December 2018

This article discusses the pressing and sintering of various refractory metal powders for the production of intermediate products as well as special cases of finished products. The metal powders considered include tungsten, molybdenum, tantalum, niobium and their alloys, as well as rhenium.
Production of Copper and Copper Alloy Powders
Authors: Pelletiers Thomas W. , Daye Wayne K.
Published: December 2018

This article describes the fundamentals of various techniques used for the production of copper and copper alloy powders. These include atomization (water, air, and gas), oxide reduction, and electrolysis. The article discusses the effects of electrolyte composition and operating conditions on the characteristics of copper and copper alloy powders.
Solidification Structures of Aluminum Alloys
Authors: Stefanescu Doru M. , Ruxanda Roxana
Published: December 2018

The most common aluminum alloy systems are aluminum-silicon, aluminum-copper, and aluminum-magnesium. This article focuses on the grain structure, eutectic microstructure, and dendritic microstructure of these systems. It provides information on microsegregation and its problems in casting of alloys. The article also illustrates the casting defects such as macroporosity, microshrinkage, and surface defects, associated with the alloys.
Solidification Structures of Titanium Alloys
Authors: Stefanescu Doru M. , Ruxanda Roxana
Published: December 2018

This article describes the development of heat-resistant titanium-base alloys and their classification into several microstructure categories based on their strengthening mechanisms. It explains the phase transformation in titanium-aluminum-base alloys and two peritectic reactions that take place in the titanium-aluminum system. The article also describes two approaches for controlling the orientation of the high-temperature alpha phase to achieve the required lamellar orientation by directional solidification in order to improve the strength and ductility of titanium-aluminum alloys. One approach is by seeding the alpha phase in the alloys, and the other is without seeding, by controlling the solidification path of alloys through appropriate alloying. The article discusses the grain refinement technique used to improve the ductility of cast titanium-aluminum alloys to a level of above 1" at room temperature and reasonable room temperature ductility in the as-cast condition. Finally, it provides information on the microstructures produced through various near-net shape manufacturing processes.
Introduction to Transformation Structures
Authors: Marder Arnold R.
Published: December 2018

This introductory article provides basic information on the various aspects of solid-state transformation: multiphase microstructures, substructures, and crystallography, which assist in characterizing the morphology of phase transformations. It contains a flowchart that illustrating the classification of transformations by growth processes.
Three-Dimensional Microscopy
Authors: Kral M.V. , Ice Gene , Miller M.K. , Uchic M.D. , Rosenberg R.O.
Published: December 2018

Three-dimensional microscopy can be used to reveal the shape, distribution, and connectivity of three-dimensional (3D) features that lie buried within an opaque material. This article discusses several experimental techniques that can be used to generate 3D images. These include serial sectioning, focused ion beam tomography, atom probe tomography, and X-ray microtomography. Nine case studies are presented that represent the work of the various research groups currently working on 3D microscopy using serial sectioning and illustrate the variants of the basic experimental techniques. The article also discusses the techniques for reconstruction and visualization of 3D microstructures with advanced computer software and hardware.
Metallography and Microstructures of Cobalt and Cobalt Alloys
Authors: Klarstrom D. , Crook P. , Wu J.
Published: December 2018

This article describes the metallurgy and microstructure of high-performance cobalt-base alloys. It discusses metallographic preparation procedures, including sectioning, mounting, grinding, polishing, etching, staining, and heat tinting. It examines the microstructure of cobalt alloys in cast, wrought, and powder metal forms, including magnetic alloys as well as several cobalt-base superalloys.
Metallography and Microstructures of Nickel and Nickel-Copper Alloys
Authors: Mankins William L.
Published: December 2018

This article explains how to prepare nickel-base alloys for metallographic examination and identifies related processing and imaging challenges. It describes sectioning, mounting, grinding, and polishing procedures along with alternative electropolishing processes. It also provides information on etching and examines the microstructure of Nickel 200, Nickel 270, Duranickel 301, Monel 400, Monel R-405, Monel K-500, and other nickel alloys.
Metallography and Microstructures of Zirconium, Hafnium, and Their Alloys
Authors: Danielson Paul E. , Sutherlin Richard C.
Published: December 2018

Zirconium, hafnium, and their alloys are reactive metals used in a variety of nuclear and chemical processing applications. This article describes various specimen preparation procedures for these materials, including sectioning, mounting, grinding, polishing, and etching. It reviews some examples of the microstructure and examination for zircaloy alloys, hafnium, zirconium, and bimetallic forms.
Microstructural Characterization of Thermal Spray Coatings
Authors: Davis J.R.
Published: December 2018

This article reviews how process variations influence the characteristics of thermal spray coatings. It describes various specimen preparation techniques, which allow accurate microstructural analysis. These techniques include sectioning, cleaning, mounting, planar grinding, fine grinding, rough polishing, and etching. The article provides information on the problems associated with specimen preparation. It concludes with a discussion on the various methods of analysis for thermal spray coatings.
Metallography of Biomedical Orthopedic Alloys
Authors: Medlin D.J. , Compton R.
Published: December 2018

Metallography plays a significant role in the quality control of metals and alloys used in the manufacture of implantable surgical devices. This article provides information and data on metallographic techniques along with images showing the microstructure of biomedical orthopedic alloys, including stainless steels, cobalt-base alloys, titanium and titanium alloys, porous coatings, and emerging materials.
Metallography of Archaeological Alloys
Authors: Wayman M.L.
Published: December 2018

Archaeometallurgists use metallography to reveal and interpret the microstructures of objects, in conjunction with the results of their chemical analyses and microanalyses. This article describes a number of special problems that occur while performing metallographic analyses on archaeological materials. It also presents case studies, with examples that illustrate situations where metallography has contributed to archaeometallurgical studies.
Analysis of the Effects of Lightning Strikes on Polymeric Composites
Authors: Hayes Brian S. , Gammon Luther M.
Published: December 2018

Lightning damage in polymer composites is manifested by damage at both the macroscopic or visual level and within the material microstructure. This article illustrates the effects of the laboratory-generated lightning strikes on polymeric composites.
Corrosion of Organic Coated Steels
Authors: Tanabe Hiroyuki
Published: December 2018

This article describes the paint systems generally used to protect steel structures, steel sheet, and bridges from corrosion, and how they deter corrosion. It provides a discussion on the basic design criteria of steel structures for corrosion protection. The article also explains the differences between prepaint and postpaint, and the steps involved in prepaint processing of steel. It presents the selection guideline for paint system evaluation. The advantages of corrosion protection are also discussed.
Corrosion of Aluminum and Aluminum Alloys
Authors: Kaufman J.G.
Published: December 2018

This article focuses on the various forms of corrosion that occur in the passive range of aluminum and its alloys. It discusses pitting corrosion, galvanic corrosion, deposition corrosion, intergranular corrosion, stress-corrosion cracking, exfoliation corrosion, corrosion fatigue, erosion-corrosion, atmospheric corrosion, filiform corrosion, and corrosion in water and soils. The article describes the effects of composition, microstructure, stress-intensity factor, and nonmetallic building materials on the corrosion behavior of aluminum and its alloys. It also provides information on the corrosion resistance of anodized aluminum in contact with foods, pharmaceuticals, and chemicals.
Gallery of Corrosion Damage
Authors: Elliott Peter
Published: December 2018

This article is a pictorial guide to forms of corrosion that draws attention to common pitfalls or situations that have caused premature corrosion, sometimes with expensive consequences. The examples used are not exhaustive; they highlight the necessity to fully examine materials, conditions, and specific circumstances that together can reduce the anticipated service life of a component or plant. The color images in this article are categorized according to the type of corrosion following the general order that is adopted in Volume 13A of ASM Handbook. The first table of the article provides a categorization of the forms of corrosion. It also provides a reference to articles or sections of articles in Volume 13A that detail the particular corrosion form or mechanism. The second table is a guide listing the figures in this article by material and by the corrosion form or mechanism illustrated.
Die Wear
Authors: Shivpuri Rajiv , Babu Sailesh , Semiatin S.L.
Published: December 2018

This article describes die wear and failure mechanisms, including thermal fatigue, abrasive wear, and plastic deformation. It summarizes the important attributes required for dies and the properties of the various die materials that make them suitable for particular applications. Recommendations on the selection of the materials for hot forging, hot extrusion, cold heading, and cold extrusion are presented. The article discusses the methods of characterizing abrasive wear and factors affecting abrasive wear. It discusses various die coatings and surface treatments used to extend the lives of dies: alloying surface treatments, micropeening, and electroplating.
Hot Upset Forging
Authors: Douglas J. Richard
Published: December 2018

This article discusses the operation of upset forging machines and selection of the machine size. It describes several types of upsetter heading tools and their materials. The article reviews the cold shearing and hot shearing methods for preparing blanks for hot upset forging. It deals with various upsetting processes: offset upsetting, double-end upsetting, upsetting with sliding dies, upsetting pipe and tubing, and electric upsetting. The article also provides information on hot forging and cold forging.
Ring Rolling
Authors: Bolin Robert
Published: December 2018

Ring rolling is a process for creating seamless ring shaped components using specialized equipment and forming processes. This article provides information on the applications of ring rolling. It discusses the types of machines used for ring rolling, namely, vertical rolling machines, radial-axial horizontal rolling machines, four-mandrel mechanical table mills, three-mandrel table mills, and automatic radial-axial multiple-mandrel ring mills. The article provides a discussion on the process control technology and ancillary operations of ring rolling. It describes the methods of producing ring blanks and the various types of blanking and rolling tools used in ring rolling process. The article concludes with a discussion on rolled ring tolerances and machining allowances.
Forging of Aluminum Alloys
Authors: Kuhlman G.W.
Published: December 2018

This article begins with discussion on forgeability and the factors affecting the forgeability of aluminum and aluminum alloys. It describes the types of forging methods and equipment and reviews critical elements in the overall aluminum forging process: die materials, die design, and die manufacture. The article discusses the critical aspects of various manufacturing elements of aluminum alloy forging, including the preparation of the forging stock, preheating stock, die heating, lubrication, trimming, forming and repair, cleaning, heat treatment, and inspection. It concludes with a discussion on the forging of advanced aluminum materials and aluminum alloy precision forgings.
Coextrusion
Authors: Srinivasan Raghavan , Hartley Craig S.
Published: December 2018

Coextrusion is defined as the simultaneous extrusion of two or more metals to form an integral product that can be carried out using conventional extrusion or drawing equipment at a temperature appropriate to the metal system being formed. This article discusses the applications, billet configurations, and metal flow modes of coextrusion. It presents the analytical studies of coextrusion: deformation energy methods, lower-bound (slab) analyses, upper-bound analyses, and finite-element analyses. These studies are used to identify the regime of material properties and process variables for which sound extrusions can be obtained. The article concludes with a discussion on the state-of-the-art of coextrusion that assists in developing process models, which accurately describe both the macroscopic and microscopic aspects of a process.
Flow Forming
Authors: Ray George , Yilmaz Deniz , Fonte Matthew , Keele Richard P.
Published: December 2018

A wide range of flow-formed open- and close-ended shapes are currently available in a variety of difficult-to-form materials, including titanium alloys and nickel-base super alloys. This article describes the two basic methods of flow forming that are characterized by the position of the rolls during the forming process. The flow forming methods include staggered-roll flow forming process and in-line flow-forming process. Typical mechanical properties of flow-formed materials in various conditions are summarized in a table. Proper process controls and subsequent product qualification tests are critical to assure optimal performance of the flow-formed tubular component. The article discusses the most commonly required process control parameters and the effects of forming speed and temperature in the flow forming process.
Evaluation of Workability for Bulk Forming Processes
Authors: Dieter George E.
Published: December 2018

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.
Design Optimization for Dies and Preforms
Authors: Chaudhary Anil , Vaze Suhas
Published: December 2018

For forming processes, optimization goals range from tuning the process parameters while keeping geometry unchanged to finding optimal geometry for intermediate dies in a multistage forming operation. This article commences with a description on the three salient steps of optimization procedures: defining the objective function, calculating the objective function, and searching an optimum design. It concludes with an example illustrating the optimization of conical-die extrusion.
Hot-Compression Testing
Authors: Dieter George E.
Published: December 2018

This article describes the use of compression tests, namely, cylindrical compression, ring compression, and plane-strain compression tests at elevated temperatures. It discusses the effects of the temperature, strain rate, and deformation heating on metals during the cylindrical compression test, with the help of flow curves. The article illustrates the testing apparatus used in the cylindrical compression test. It describes the issues regarding friction and temperature, and strain-rate control with proper test equipment and experimental planning during the ring compression test and plane-strain compression test. The article also reviews the testing conditions, procedures, and advantages of hot plane-strain compression test.
Hot Working Simulation by Hot Torsion Testing
Authors: Pickens Joseph R.
Published: December 2018

This article summarizes the types of hot working simulation tests such as hot tension, compression, and torsion testing used in the assessment of workability. It illustrates the use of hot torsion testing for the optimization of hot working processes. The article concludes with information on some hot torsion application examples.