bluuebunny/crossref_metadata_2025 huggingface dataset:
Cemented Carbide Secondary Operations
Authors: Shearer Thomas R. , Mehrotra Pankaj K.
Published: December 2018

This article describes the secondary operations for cemented carbide parts, namely, diamond grinding, honing, electrical discharge machining, and brazing after sintering to achieve desired results, such as specified size, shape, edge condition, and surface finish.
Cemented Carbide Quality Control
Authors: Runyon Gary , Sargent Binky
Published: December 2018

Quality control of cemented carbides includes the evaluation of physical and chemical properties of constituent raw material powders, powder blends/formulations, green compacts, and fully dense finished product. This article provides a summary of the underlying principles and size ranges for the American Society for Testing and Materials (ASTM) standard methods of particle sizing and distribution. It presents the methods used to analyze the chemical composition of cemented carbide materials in a tabular form. The article also presents information on microstructural evaluation and physical and mechanical property evaluation of cemented carbides.
Sintering of Hardmetals
Authors: Bose Animesh , Sadangi Rajendra , Mehrotra Pankaj K.
Published: December 2018

This article discusses two major sintering methods: pressureless and pressure-assisted sintering. Pressureless sintering techniques include vacuum and partial-pressure, hydrogen, and microwave sintering. Pressure-assisted consolidation techniques include overpressure sintering, sintering followed by postsinter hot isostatic pressing, hot pressing, and several rapid hot consolidation techniques. The article describes nitrogen sintering and the sintering of cermets. It reviews the furnaces used for sintering and presents the lubrication removal techniques. The article also outlines the need to control carbon and oxygen to obtain optimal properties and explains microstructure development and grain size control.
Copper-Infiltrated Steels
Authors: Pelletiers Thomas W. , Daye Wayne K.
Published: December 2018

The two most important classes of materials that are manufactured via infiltration methods are copper- and silver-infiltrated refractory metals and refractory carbides, and copper-infiltrated steels. This article focuses on copper-infiltrated steels and discusses the basic requirements for infiltration, which is a technique that is only applicable to material systems that meet certain requirements. It addresses these requirements and describes the conventional (partial) infiltration process of powder metallurgy (PM) steel. The materials used in the process, such as matrix and infiltrant, are discussed. The article also details several criteria used to evaluate the performance of an infiltration process. It concludes with information on alloy steels and fully infiltrated steels.
Production of Powder Metallurgy Carbon and Low-Alloy Steels
Authors: Marucci Michael L. , Catanese James A.
Published: December 2018

This article briefly reviews the production methods and characteristics of plain carbon and low-alloy water-atomized iron and steel powders, high-porosity iron powder, carbonyl iron powder, and electrolytic iron powder. It emphasizes on atomized powders, because they are the most widely used materials for ferrous powder metallurgy. The article provides information on the properties and applications of these powders. It also includes an overview of diffusion alloying, basics of admixing, and bonded premixes.
Warm Compaction and Warm Die Compaction
Authors: Hanejko Francis
Published: December 2018

Warm compaction uses both powder heating and die heating to effect higher component densities, whereas warm die compaction uses only die heating to achieve higher density. This article explains the influences of green and sintered properties and pore-free density during compaction of materials. It provides information on the concept of pore-free density and process considerations: die heating and powder heating. The article concludes with a review of the tooling design for warm compaction.
Particle Size and Size Distribution
Authors: Iacocca Ronald G.
Published: December 2018

Particle size and size distribution have a significant effect on the behavior of metal powders during their processing. This article provides an overview of the sample preparation process for particle size measurement, which is a key step in the measurement of particle size distributions. Common particle size measuring techniques discussed in this article include sieve analysis, quantitative image analysis, laser diffraction, sedimentation methods, aerodynamic time-of-flight method, electrical zone sensing, and photon correlation spectroscopy. The advantages and disadvantages of these methods are reviewed.
Friction Powder Metallurgy Materials
Authors: Hu Bo
Published: December 2018

Friction materials are the components of a mechanism that converts mechanical energy into heat upon sliding contact. This article discusses the selection criteria, manufacturing process, and applications of friction powder metallurgy materials. It provides information on the manufacturing process of powder metallurgy friction materials through a process of mixing/blending, compacting, and sintering. The final machining that they undergo, to ensure that they meet dimensional specifications, is also discussed.
Machining of Powder Metallurgy Materials
Authors: Christopherson Denis
Published: December 2018

This article provides a discussion on the machining guidelines that serve to improve the machinability of powder metallurgy materials. It provides a description of various cutting tool grades and tool-edge design and describes the machining conditions for common operations, namely, turning, drilling, tapping, grinding, and finishing. The article introduces a few overlooked details that can heavily influence the performance and success of the machining process. These include dwell, margin design on round tools, and proper edge hone.
Processing of Powder Metallurgy Bronze and Brass
Authors: Daye Wayne K. , Pelletiers Thomas W.
Published: December 2018

Bronze and brass alloys are two key classes of materials in copper-base powder metallurgy applications. They are often compacted using mechanical or hydraulic pressing machines. This article provides an overview of the powder pressing process, providing information on the powder properties of bronze and brass and the roles of lubricant and compaction dies in the pressing process. It discusses the structural defects that originate during the compaction process. The article also describes the major factors that influence the sintering response in bronze, prealloyed bronze, brass, and nickel-silver.
Production Sintering Practices
Authors: Warzel Roland
Published: December 2018

This article provides information on the most frequently used atmospheres in commercial sintering of powder metallurgy iron and steel materials. These include endothermic, exothermic, dissociated ammonia, pure hydrogen, and nitrogen-base atmospheres. The article discusses sintering of iron and iron-graphite powder, iron-copper and iron-copper graphite, and alloy steels. The effects of various sinter conditions on the amount of combined carbon formed in the steel are also discussed. The article concludes with information on high-temperature sintering and sinter hardening.
Microstructure of Powder Metallurgy Tool Steels
Authors: Beiss Paul
Published: December 2018

The microstructure in the longitudinal direction of conventional high-alloy tool steels (HATS) depends very much on the degree of hot working. Comparing different processes, the highest processing temperature proves to be decisive for coarseness of the microstructure. This article provides a discussion on the microstructure of conventional HATS and hot isostatically pressed high-speed steel. The effects of the processing in cold worked HATS are illustrated.
Secondary Operations and Quality Control for Refractory Metal Powders
Authors: Caldwell Steven G. , Kestler H. , Reheis N.
Published: December 2018

Refractory metals are typically processed from powders into ingots that are subsequently swaged into round bars or rolled into plates. Secondary operations are required to fabricate more complex refractory metal components. This article discusses two such secondary operations, namely, machining and joining processes for tungsten, tungsten heavy alloys, molybdenum, tantalum, niobium, and rhenium components. It describes the various types of metal joining processes, including mechanical fastening, brazing, and welding.
Porous Powder Metallurgy Technology
Authors: Eisenmann Mark , Morgan Richard
Published: December 2018

The technology to fabricate lower-density, porous powdered metal materials provides unique engineering solutions for many applications. This article summarizes the characteristics and applications of porous powder metallurgy technology, as well as the fabrication methods employed.
Properties and Selection of Powder Metallurgy Copper and Its Alloys
Authors: Pelletiers Thomas W. , Daye Wayne K.
Published: December 2018

Selection of the process steps used, powder chosen, and lubricant choice have marked effects on the quality of a sintered component. This article describes the alloy composition, mechanical and structural properties, processing routes, and advantages of the common members of the copper alloy family, namely, pure copper, brass, and bronze, which all aid in the selection of the suitable material for structural and bearing applications. It outlines the structural applications of nickel silver alloys.
Fabrication of Near-Net Shape Cost-Effective Titanium Components by Use of Prealloyed Powder and Hot Isostatic Pressing
Authors: Samarov V. , Seliverstov D. , (Sam) Froes F.H.
Published: December 2018

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.
Introduction to Full Density Powder Metallurgy
Authors: Samal Prasan K.
Published: December 2018

This article provides a basic introduction to the various aspects of full density powder metallurgy, including properties, applications, processing methods, and process parameters.
Computer Modeling of Solidification Microstructures
Authors: Stefanescu Doru M. , Ruxanda Roxana
Published: December 2018

Computational modeling assists in addressing the issues of solid/liquid interface dynamics at the microlevel. It also helps to visualize the grain length scale, fraction of phases, or even microstructure transitions through microstructure maps. This article provides a detailed account of the general capabilities of the various models that can generate microstructure maps and thus transform the computer into a dynamic microscope. These include standard transport models, phase-field models, Monte Carlo models, and cellular automaton models.
Ordered Structures
Authors: Regina Jonathan
Published: December 2018

Superlattice is an ordered array of atoms that occur during their rearrangement from random site locations in the disordered solution to specific lattice sites in the ordered structure during phase transformation. This article provides a description of antiphase boundaries, their dislocations and degrees of ordering (long and short order). It focuses on the common superlattice structures and ordered phases observed in copper-gold and iron-aluminum alloy systems. These superlattice types can be referred to by Strukturbericht symbols and the prototype phase.
Metallography and Microstructures of Heat-Resistant Alloys
Authors: Vander Voort George F. , Lucas Gabriel M. , Manilova Elena P.
Published: December 2018

This article discusses the specimen preparation of three types of cast and wrought heat-resistant alloys: iron-base, nickel-base, and cobalt-base. Specimen preparation involves sectioning, mounting, grinding, polishing, and etching. The article illustrates the microstructural constituents of cast and wrought heat-resistant alloys. It describes the identification of ferrite by magnetic etching. The transmission electron microscopy examination of the fine strengthening phases in wrought alloys and bulk extraction in heat-resistant alloys are included. The article also reviews the gamma prime phase, gamma double prime phase, eta phase, laves phase, sigma phase, mu phase, and chi phase in wrought heat-resistant alloys.
Light Microscopy
Authors: Vander Voort George F.
Published: December 2018

This article provides information on the basic components of a light microscope, including the illumination system, collector lens, and optical and mechanical components. It describes optical performance in terms of image aberrations, resolution, and depth of field. The article discusses the examination of specimen surfaces using polarized light, phase contrast, oblique illumination, dark-field illumination, bright-field illumination, interference-contrast illumination, and phase contrast illumination. Special techniques and devices that may be used with the optical microscope, to obtain additional information, are also described. The article concludes with information on photomicroscopy and macrophotography.
Metallography and Microstructures of Precious Metals and Precious Metal Alloys
Authors: van der Lingen Elma , Cornish Lesley , Taylor Stefanie , Süss Rainer , Grice Stewart
Published: December 2018

This article explains how to prepare precious metal test samples for metallographic examination. It discusses cutting, mounting, grinding, polishing, and etching and addresses some of the challenges of working with small, relatively soft specimens. It includes dozens of example micrographs, comparing and contrasting the microstructural features of gold, platinum, iridium, palladium, and ruthenium-base alloys. It examines pure gold, intermetallic gold compounds, gold and platinum jewelry alloys, platinum-containing shape memory alloys, and alloys consisting of platinum, aluminum, and copper.
Metallography and Microstructures of Uranium and Its Alloys
Authors: Fairman Henry E. , Kelly Ann
Published: December 2018

This article discusses the principles of physical metallurgy and metallography of depleted uranium. It describes the techniques involved in the preparation of thin foils for transmission electron microscopy and illustrates the resulting microstructure of uranium and uranium alloys, with the aid of black and white images. The article also provides information on the applications of etching and examination of uranium alloys, at both macro and micro scales, in characterizing the grain structures, segregation patterns, inclusions, and the metal flow geometries produced by solidification and mechanical working processes.
Metallography and Microstructures of Powder Metallurgy Alloys
Authors: Pease Leander F. , Pease Douglas L.
Published: December 2018

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.
Metallography of Cemented Carbides
Authors: Santhanam A.T.
Published: December 2018

This article contains tables that list standard reduction potentials for electrochemical reactions. The first table lists reactions alphabetically by element of interest. The second table is ranked by potential value. Potential is measured versus the Standard Hydrogen Electrode which has a value of 0.0000 V. Reactions with more than one voltage indicate that results have not been reconciled. Parenthetical materials not needed to balance reactions are catalysts.
Rough Grinding and Polishing of Fiber-Reinforced Composite Samples
Authors: Hayes Brian S. , Gammon Luther M.
Published: December 2018

Rough grinding and polishing of specimens are required to prepare fiber-reinforced composite samples for optical analysis. This article discusses the consumables, process variables, and the equipment that influence the sample preparation procedure. It describes the hand and automated grinding methods. The article summarizes the rough and final polishing steps for both hand and automated techniques. Common artifacts that may be created during grinding and polishing steps of composite samples are reviewed. These include scratches, fiber pull-out, matrix smears, streaks, erosion of different phases, and fiber and sample edge rounding and relief.
Special Sample Preparation and Polishing for Fiber-Reinforced Composites
Authors: Hayes Brian S. , Gammon Luther M.
Published: December 2018

This article focuses on the sample preparation methods for titanium honeycomb composites, boron fiber composites, and titanium/polymeric composite hybrids. These include mounting, sectioning, grinding, and polishing. The article also provides information on the sample preparation of unstaged and staged prepreg materials for optical analysis.
Void Analysis of Composite Materials
Authors: Hayes Brian S. , Gammon Luther M.
Published: December 2018

Voids in fiber-reinforced composite materials are areas that are absent of the composite components: matrix (resin) and fibers. Voids have many causes but generally can be categorized as voids due to volatiles or as voids that result from entrapped air. This article describes the analysis of various types of voids. It reviews techniques for analysis of voids at ply-drops, voids due to high fiber packing, and voids that occur in honeycomb core composites. The final section of the article discusses void documentation through the use of nondestructive inspection techniques and density/specific gravity measurement methods.
Microcrack Analysis of Composite Materials
Authors: Hayes Brian S. , Gammon Luther M.
Published: December 2018

This article describes the microcrack analysis of composite materials using bright-field illumination, polarized light, dyes, dark-field illumination, and epi-fluorescence.
Impact Response of Composites
Authors: Hayes Brian S. , Gammon Luther M.
Published: December 2018

This article describes methods for analyzing impact-damaged composites in the aircraft industry. These include C-scan and x-radiography methods and optical microscopy. The article reviews brittle-matrix composite and tough-matrix composite failures. It explains the different types of composite failure mechanisms such as thermoplastic-matrix composite failure mechanisms, untoughened thermoset-matrix composite failure mechanisms, toughened thermoset-matrix composite failure mechanisms, dispersed-phase and rubber-toughened thermoset-matrix composite failure mechanisms, and particle interlayer-toughened composite failure mechanisms.
Analysis of Honeycomb-Cored Sandwich Structure Composites
Authors: Hayes Brian S. , Gammon Luther M.
Published: December 2018

Honeycomb-cored sandwich panels increase part stiffness at a lower weight than monolithic composite materials. This article illustrates an area of a honeycomb-cored sandwich structure composite cross section that is viewed using transmitted polarized light. This area shows the differences in the constituents and resin intermingling. The article discusses the factors that govern the honeycomb core movement and honeycomb core crush, with illustrations. Some common tests performed on honeycomb composites to characterize the skin-to-core bond strength are the climbing drum peel and flatwise tensile tests. The article concludes with a description on the reasons for core failure, which are analyzed after these tests.
Corrosion of Hafnium and Hafnium Alloys
Authors: Holmes D.R.
Published: December 2018

This article describes the processes involved in the production of hafnium and its alloys. It discusses the physical, mechanical and chemical properties of hafnium. The aqueous corrosion testing of hafnium and its alloys is detailed. The article reviews the corrosion resistance of hafnium in specific media, namely, water, steam, hydrochloric acid, nitric acid, sulfuric acid, alkalis, organics, molten metals, and gases. Forms of corrosion, namely, galvanic corrosion, crevice corrosion, and pitting corrosion are included. The article explains the corrosion of hafnium alloys such as hafnium-zirconium alloys and hafnium-tantalum alloys. It also deals with the applications of hafnium and its alloys in the nuclear and chemical industries.
Corrosion of Beryllium and Aluminum-Beryllium Composites
Authors: Haws Warren J.
Published: December 2018

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.
Corrosion of Metal-Matrix Composites
Authors: Hihara L.H.
Published: December 2018

This article begins with the discussion on the background of metal-matrix composites (MMC) and moves into a broad description of the general parameters affecting the corrosion of MMC. It discusses the primary sources of MMC corrosion that include galvanic corrosion between MMC constituents, chemical degradation of interphases and reinforcements, microstructure-influenced corrosion, and processing-induced corrosion. The article elaborates on the corrosion behavior of specific aluminum, magnesium, titanium, copper, stainless steel, lead, depleted uranium, and zinc MMCs systems. It concludes with a description on the corrosion control of MMCs using protective coatings and inhibitors.
Performance of Refractories in Severe Environments
Authors: Bennett James P. , Kwong Kyei-Sing , Oprea George , Rigaud Michel , Winder Stephen M.
Published: December 2018

This article provides an overview of the corrosion theory relating to refractories on the basis of acid/base reactions, thermodynamics, and kinetic considerations. The tests to evaluate refractory corrosive wear are reviewed. The article describes the specific refractories used in steel, glass, aluminum, and chemical-resistant applications. Specific material issues that should be considered or evaluated when choosing or using refractory materials are discussed.
Performance of Ceramics in Severe Environments
Authors: Jacobson Nathan S. , Fox Dennis S. , Smialek James L. , Opila Elizabeth J. , Dellacorte Christopher , Lee Kang N.
Published: December 2018

This article examines the high-temperature oxidation of silica-forming ceramics under constant temperature and cyclic conditions. The effects of water vapor, impurities, and molten salts are discussed. The article describes the oxidation and corrosion of silica-forming composites, oxide ceramics, non-silica forming nitrides, carbides, and borides. The performance of environmental barrier coatings by material type is also discussed. The article also explains the effects of oxidation and corrosion on the mechanical properties of ceramic-matrix composites. It concludes with information on high-temperature applications, wear properties, and the microscopic analyses of advanced ceramics.
Introduction to Bulk-Forming Processes
Authors: Semiatin S.L.
Published: December 2018

Metalworking is one of the three major technologies used to fabricate metal products. This article tabulates the classification of metal forming processes. It discusses different types of metalworking equipment, including rolling mills, ring-rolling machines, and thread-rolling and surface-rolling machines. The article outlines the significant characteristics of pressing-type machines: load and energy characteristics, time-related characteristics, and accuracy characteristics. It summarizes different specialized processes such as advanced roll-forming methods, equal-channel angular extrusion, incremental forging, and microforming. The article describes the thermomechanical processing of nickel- and titanium-base alloys and concludes with information on the advancements in process simulation.
Isothermal and Hot-Die Forging
Authors: Montero R.E. , Housefield L.G. , Mace R.S.
Published: December 2018

Hot-die forging and isothermal forging are unique forging methods developed to forge materials that are difficult or impossible to forge by conventional means. This article presents a comparative study on hot-die forging and isothermal forging. It discusses forging parameters, process selection considerations, design guidelines, alloy types and selection, and the advantages and disadvantages of hot-die forging and isothermal forging. The article discusses the application of the finite-element analysis modeling to design.
Cold Extrusion
Authors: Bhupatiraju Murali , Greczanik Robert
Published: December 2018

Cold extrusion is a push-through compressive forming process with the starting material (billet/slug) at room temperature. This article provides information on the different types of steels that can be cold extruded. Mechanical presses and hydraulic presses that are specifically designed for cold extrusion with high rigidity, accurate alignment, and long working strokes are described. The article details the factors that are critical in cold extrusion: punch design, die design, and tool design. It summarizes the role of lubricants during extrusion of steel, such as soap lubricant and polymer lubricants. The article describes several procedures for extruding specific steel parts such as tubular parts and stepped shafts. It lists problems such as tool breakage and galling or scoring of tools and explains cold extrusion of aluminum, copper, and nickel alloy parts. The article also discusses the impact extrusion of magnesium alloys.
Transformation and Recrystallization Textures Associated with Steel Processing
Authors: Kestens Leo , Jonas John J.
Published: December 2018

The processing of steel involves five distinct sets of texture development mechanisms, namely, austenite deformation, austenite recrystallization, gamma-to-alpha transformation, ferrite deformation, and static recrystallization during annealing after cold rolling. This article provides an introduction on crystallographic textures. It discusses the effects of austenite rolling and recrystallization on the texture and transformation behavior of recrystallized austenite and deformed austenite. The article illustrates the overall summary of the rolling and transformation behavior. It details cold-rolling textures, annealing textures, and recrystallization textures of steel samples. The article concludes with a summary of texture development during cold rolling and annealing.
Evolution of Microstructure during Hot Working
Authors: Semiatin S.L.
Published: December 2018

This article reviews the general aspects of microstructure evolution during thermomechanical processing. The effect of thermomechanical processing on microstructure evolution is summarized to provide insight into the aspect of process design. The article provides information on hot working and key processes that control microstructure evolution: dynamic recovery, static recovery, recrystallization, and grain growth. Some of the key phenomenological descriptions of plastic flow and microstructure evolution are also summarized. The article concludes with a discussion on the modeling of microstructure evolution.
Bulk Workability of Metals
Authors: Dieter George E.
Published: December 2018

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.
Torsion Testing to Assess Bulk Workability
Authors: Semiatin S.L. , Jonas J.J.
Published: December 2018

This article discusses the equipment design, procedures, experimental considerations, and interpretation of the torsion tests used to establish workability. It describes the application of torsion testing to obtain flow-stress data and to gage fracture-controlled workability and flow-localization-controlled failure. The article discusses the torsion test used to establish the processing parameters that are required to produce the desired microstructures.
Shearing of Sheet, Strip, and Plate
Authors: Chen L.
Published: December 2018

Shearing is a method for cutting a material piece into smaller pieces using a shear knife to force the material past an opposition shear knife in a progression form. This article describes the principles, attributes, and defects of straight-knife shearing. The equipment, materials used, and the operating parameters are discussed. The article provides information on the applications of rotary shearing. It concludes with a discussion on devices equipped with shearing machines for protecting personnel from the hazards of shear knives, flywheels, gears, and other moving parts.
Flattening, Leveling, Slitting, and Shearing of Coiled Product
Authors: Chen L.
Published: December 2018

Metal production mills produce flat metal sheet and strip products into coil forms that are subjected to further fabrication for shape correction. This article provides a discussion on the principle of shape correction and describes the role of various fabrication processes in shape correction. These processes include flattening, leveling, slitting, and cut-to-length.
Thermal Forming of Sheet and Plate
Authors: Male Alan
Published: December 2018

This article begins with a discussion on the energy sources used for thermal forming. These include electric induction coil, gas flame, plasma torch, and laser beam. The article discusses the mechanisms of forming and different modes of deformation. It describes the effect of process and material parameters on forming and the effect of metallurgical changes on mechanical property and microstructure of stainless steel. The article concludes with information on the applications of thermal forming.
Statistical Analysis of Forming Processes
Authors: Keeler Stuart
Published: December 2018

Statistics are extremely important tools in the operation of press shops, providing numerical process analysis capabilities. The most common use of statistics in the press shop is statistical process control (SPC) that uses statistical techniques such as control charts to analyze a process or its output to enable appropriate actions to be taken to achieve and maintain a state of statistical control. This article discusses the role of statistics in sheet metal forming operations, both in terms of SPC techniques, such as control charting, statistical deformation control, and experimental design, including single-variable studies, multivariable studies, and Taguchi experiments.
Chemical Thermodynamics and Kinetics
Authors: Katz Seymour
Published: December 2018

This article introduces the fundamental concepts of chemical thermodynamics and chemical kinetics in describing presolidification phenomena. For metallurgical systems, the most important thermodynamic variables are enthalpy and Gibbs free energy. A qualitative demonstration of the interrelationship between phase diagrams and thermodynamics is presented. The article discusses processes that generally limit the rates of chemical processes. These include nucleation of the product phase and interphase mass transport. The article provides a discussion on the dissolution of alloy with melting point lower than bath temperature and dissolution of alloy that is solid at bath temperatures.
Plasma Melting and Heating
Authors: Lampson Robin , Telfer Todd
Published: December 2018

Plasma melting is a material-processing technique in which the heat of a thermal plasma is used to melt a material. This article discusses the two typical design principles of plasma torches in the transferred mode: the tungsten tip design and the hollow copper electrode design. It briefly describes the sources of atmospheric contamination in plasma melting furnaces and their control measures. The equipment used in plasma melting furnaces are also discussed. The article provides a detailed discussion on various plasma melting processes, such as plasma consolidation, plasma arc remelting, plasma cold hearth melting, and plasma casting.
Plane Front Solidification
Authors: Kurz Wilfried
Published: December 2018

One impressive example of plane front solidification (PFS) is the industrial production of large silicon single crystals, used mainly as substrates for integrated circuits. This article explores the PFS of a single phase, without taking convection into account. It discusses the solute build-up at the solid-liquid interface forming transients and steady state, the morphological stability/instability and perturbation theory, and rapid solidification effects, including solute trapping and oscillatory instabilities. The article presents a microstructural selection map that gives an overview of interface stability as a function of composition for a given alloy.
Interpretation and Use of Cooling Curves—Thermal Analysis
Authors: Fredriksson H.
Published: December 2018

Thermal analysis is a classical method of determining phase diagrams and can be used to analyze the deviation from solidification under equilibrium conditions. This article discusses the use of thermal analysis in industrial processes and in research. It describes the theoretical basis of simplified and differential thermal analysis. The article explains how to determine the liquidus and solidus temperatures by using cooling curves.
Practical Issues in Computer Simulation of Casting Processes
Authors: Ohnaka Itsuo
Published: December 2018

This article illustrates the simulation procedure of casting process. It describes important elements and points of the simulations. These include the setting of clear simulation objectives, selection of proper simulation code, hints in modeling of shape and phenomena, initial and boundary conditions, physical properties, enmeshing, and evaluation of simulation results. The article provides some insights into the application of models to real world problem for foundry process engineers.
Thermophysical Properties
Authors: Valencia Juan J. , Quested Peter N.
Published: December 2018

There are several main sources of thermophysical property data that provide the most authoritative and comprehensive compilations of critically and systematically evaluated data that are presently available. This article provides thermophysical property data to assist in the materials properties selection for the simulation of casting processes. The measurements of thermophysical property are difficult due to high temperatures and the reactivity of some alloys. The article discusses strategies adopted to minimize the effects of high temperatures and the reactivity of alloys. It presents thermophysical properties for pure metals and some commercial alloys, and tabulates enthalpy of fusion and the solidus and liquidus temperatures for various alloys of commercial interest. The article also tabulates density, thermal conductivity, surface tension, and viscosity for some commercial alloys.
Aggregates and Binders for Expendable Molds
Authors: Jorstad John , Krusiak Mary Beth , Serra John O. , Fay Vic La
Published: December 2018

This article reviews the basic types of mold aggregates and bonding methods for expendable molds and coremaking. It provides an overview of mold media and the basic types of sands and their properties. The most significant clays used in green sand operations, such as bentonites, are discussed. The article describes the methods of sand bonding with inorganic compounds. It provides a description of resin-bonded sand systems, namely, no-bake binder systems, heat-cured binder systems, and cold box binder systems. The article concludes with a discussion on the media used for expendable molds, namely, ceramic shells and rammed graphite, for casting reactive metals such as titanium or zirconium.
High-Pressure Die Casting
Authors: Butler William A.
Published: December 2018

This article provides a comprehensive discussion on die casting alloy types and casting processes used in high-pressure die casting. It presents the advantages and disadvantages of high-pressure die casting and describes the product design for the process. The article concludes with information on metal injection process of high-pressure die casting.
Squeeze Casting
Authors: DasGupta Rathrindra
Published: December 2018

This article discusses the types of squeeze-casting machines and the advantages of squeeze casting. It discusses the considerations required for the casting and tooling design process of squeeze casting. The article describes the various factors affecting the squeeze-cast products and outlines few of the key process characteristics. It provides information on the applications of squeeze-cast and contains a table that compares the tensile, hardness, and impact properties of select squeeze-cast aluminum alloys with those obtained from conventional casting processes.
Casting Practice: Guidelines for Effective Production of Reliable Castings
Authors: Campbell John
Published: December 2018

This article provides a discussion on ten rules for the effective production of reliable castings. The rules include good-quality melt, liquid front damage, liquid front stop, bubble damage, core blows, shrinkage damage, convection damage, segregation, residual stress, and location points.
Dross, Melt Loss, and Fluxing of Light Alloy Melts
Authors: Groteke Daniel E. , Neff David V.
Published: December 2018

Dross, which is the oxide-rich surface that forms on melts due to exposure to air, is a term that is usually applied to nonferrous melts, specifically the lighter alloys such as aluminum or magnesium. This article describes dross formation, economic implications of dross, in-plant enhancement or recovery of dross, and ways to reduce dross formation. It discusses the influence of melter type on dross generation and the influence of charge materials and operating practices on melt loss. Fluxing is a word applied in a broad sense to a number of melt treating methods. The article discusses in-furnace treatment with chemical fluxes.
Aluminum and Aluminum Alloy Castings
Authors: Fred Major J.
Published: December 2018

This article begins with a discussion on the effects of alloying and impurity elements on the properties of aluminum cast alloys and their chemical compositions. It describes various means of structural control, namely, chemistry control, control of element ratios based on the stoichiometry of intermetallic phases, and control of solidification conditions. The article discusses the modification and grain refinement of aluminum-silicon alloys by the use of modifiers and refiners to influence eutectic and hypereutectic structures in aluminum-silicon alloys. It provides information on the foundry alloys for specific casting applications. The article concludes with a discussion on the heat treatment practices and properties of aluminum casting alloys.
Zirconium and Zirconium Alloy Castings
Authors: Sutherlin Richard C.
Published: December 2018

This article describes typical foundry practices used to commercially produce zirconium castings. The foundry practices are divided into two sections, namely, melting and casting. The article discusses various melting processes, such as vacuum arc skull melting, induction skull melting, and vacuum induction melting, and various casting processes, such as rammed graphite casting, static and centrifugal casting, and investment casting. It explains the evaluation and testing of the process. The article provides information on the mechanical and chemical properties of zirconium castings.
Casting Design Issues and Practices
Authors: Stoll H.W.
Published: December 2018

This article focuses on casting design in general and on sand and permanent mold aluminum casting in particular. It examines the casting design process from a variety of design and processing perspectives. Excessive design iterations can adversely impact the casting design. The article summarizes several strategies for improving the traditional casting design process. It also proposes some possible approaches for implementing these strategies. The article presents a vision for the development of comprehensive casting design guidelines along with specific development objectives.
Introduction to Machining Processes
Authors: Black J. T.
Published: December 2018

This article provides an overview of the independent and dependent variables of a machining process. Independent variables include workpiece material, specific machining processes, and tool materials and geometry. Cutting force and power, surface finish, and tool wear and failure are some dependent variables discussed. The article also describes the relations between the input variables and process behavior.
Tool Wear and Tool Life
Authors: Kendall L. Alden
Published: December 2018

Cutting tool wear is a production management problem for manufacturing industries. It occurs along the cutting edge and on adjacent surfaces. This article describes steady-state wear mechanisms, tertiary wear mechanisms, and tool replacement. It provides information on tool failure and its consequences. The article details the modeling of tool wear by using the Taylor's tool life equation. The article concludes with information on the requirements of a successful tool life testing program: the test plan objective, designing the test, conducting the test, analyzing the results, and applying the results.
Ceramics
Authors: Komanduri Ranga , Samanta Shyam K.
Published: December 2018

Ceramics are materials with the potential for a wide range of high-speed finishing operations and for high removal rate machining of difficult-to-machine materials. This article describes the production process, composition, properties, and applications of ceramic tool materials. It presents a comprehensive discussion on the properties and composition of alumina-base tool materials, including alumina and titanium carbide, alumina-zirconia, and silicon carbide whisker reinforced alumina, and silicon nitride base tool materials.
Tool Condition Monitoring Systems
Authors: Stockline Larry E.
Published: December 2018

In-process tool monitoring systems can electronically detect excessive tool wear or warn of impending tool failure to lessen machine downtime and prevent the production of out-of-tolerance parts. This article discusses the sensing technology available for manufacturing applications, as wells as the advantages and disadvantages of this technology. It describes the roles of the three basic elements to any modern sensing system: sensing source, signal amplifier, and microprocessor or translator. The article reviews two case studies from two different ends of the metal removal spectrum, broaching and drilling, to emphasize the cost effectiveness of using a tool condition monitoring system.
Grinding Equipment and Processes
Authors: Ault William N.
Published: December 2018

Metal is removed from the workpiece by the mechanical action of irregularly shaped abrasive grains in all grinding operations. This article discusses three primary components of grinding wheels, namely, abrasive (the cutting tool), bond (the tool holder), and porosity or air for chip clearance and/or the introduction of coolant. It describes the compositions and applications of coated abrasives and types of grinding fluids, such as petroleum-base and mineral-base cutting oils, water-soluble oils, synthetic fluids, semisynthetic fluids, and water plus additives. The article concludes with information on different types of grinding processes, namely, rough grinding, precision grinding, surface grinding, cylindrical grinding, centerless grinding, internal grinding, and tool grinding.
Electrochemical Grinding
Authors: Phillips Robert E.
Published: December 2018

This article describes the various characteristics of electrochemical grinding (ECG). It discusses grinding methods that can be performed with ECG components, namely, the electrolyte delivery and circulating system, the electrolyte, the DC power supply, grinding wheel, and the workpiece. Grinding, surface grinding, internal grinding, form grinding, and cylindrical grinding are discussed. The article also lists the advantages, disadvantages, and applications of ECG.
Electrostream and Capillary Drilling
Authors: Newton M. Anthony
Published: December 2018

This article describes the applications, process capabilities, and limitations and advantages of electrostream and capillary drilling. It describes equipment and tooling used for electrostream and capillary drilling. These include electrostream and capillary drilling machines, power supplies, electrolyte system, part holding fixtures, cathode holders, and cathode tubes. Key process parameters for electrostream and capillary drilling are also discussed.
Thermal Energy Method
Authors: Fisher Thomas
Published: December 2018

This article discusses the principles of operation, capabilities, and limitations of the thermal energy method of deburring, with illustrations.
Introduction and Basic Theory of Wear
Authors: Lim S.C. , Batchelor Andrew W. , Lim C.Y.H.
Published: December 2018

This article provides a summary of the concepts discussed in the articles under the Section “Introduction and Basic Theory of Wear” in ASM Handbook, Volume 18, Friction, Lubrication, and Wear Technology.
Transition Metal Dichalcogenide-Based (MoS2, WS2) Coatings
Authors: Scharf T.W.
Published: December 2018

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 MoS2 and WS2 coatings. It discusses the rolling-torque behavior and applications of vapor-deposited pure and composite MoS2 and WS2 coatings. The article concludes with information on various forms of TMD lubrication, namely, oils, greases, microparticle and nanoparticle additives.