Search Results for castings

This article focuses on the specimen preparation procedures of austenitic manganese steels: sectioning, mounting, and grinding. It provides information on macroexamination and microexamination of a fracture surface, the microstructure and special features of austenitic manganese steels, and the alloying elements used.

This article reviews the fatigue and fracture properties of aluminum alloy castings, specifically alloys A356 and A357/D357 (all-T6) and alloy A201-T7, from the perspective of both design and manufacturing considerations. In addition, it provides an overview of the roles played by microstructure, manufacturing processes, test conditions, and casting design in determining the fatigue and fracture properties of aluminum casting alloys.

This article discusses various machining techniques of zinc alloy die castings. These include turning, boring, drilling, reaming, tapping, die threading, milling, and sawing. In addition, the article describes the factors that influence machinability of the zinc alloy die castings.

Steel castings can be made from any of the many types of carbon and alloy steel produced in wrought form. They are divided into four general groups according to composition. Carbon and low-alloy steel castings can meet a wide range of application requirements because composition and heat treatment can be selected to achieve specific combinations of properties, including hardness, strength, ductility, fatigue, and toughness. This article discusses physical, mechanical, and engineering properties as well as fatigue properties and the effects of section size and heat treatment. Highly stressed steel castings for aircraft and for high-pressure or high-temperature service must pass rigid nondestructive inspection.

This article presents a detailed discussion on typical thermal treatment practices for hardening of various aluminum casting alloys. These practices are solution treatment, quenching or cooling, preaging, and artificial aging at an elevated temperature. The aluminum casting alloys considered here are: Al-Cu and Al-Cu-Mg (2xx) alloys, Al-Zn-Mg (7xx) alloys, Al-Si-Mg alloys, Al-Si-Cu, and Al-Si-Cu-Mg alloys.

Hot isostatic pressing (HIP) is used to eliminate porosity in castings. This article provides a history and an overview of the HIP system. It illustrates the reasons for using HIP and discusses the criteria for selecting HIP process parameters. The main mechanisms by which pores are eliminated during HIP are reviewed. The article describes the effect of HIP on the mechanical properties, shape, and structure of castings as well as the effect of inclusions on as-HIPed properties. It examines the problems encountered in HIP and their solution. The article concludes with information on the economics of HIP processing.

The combination of high strength-to-weight ratio, excellent mechanical properties, and corrosion resistance makes titanium the best material choice for many critical applications. This article begins with a description of the historical perspective of titanium casting technology. It discusses the types of molding methods, such as rammed graphite molding and lost-wax investment molding. The article provides information on the casting design, melting, postcasting, and pouring practices. It describes the microstructure and mechanical properties of Ti-6AI-4V alloy. The article examines the product applications of titanium alloy castings. The tensile properties, standard industry specifications, and chemical compositions of various titanium alloy castings are tabulated.

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. Various casting processes, such as rammed graphite casting, static and centrifugal casting, and investment casting are reviewed. The article also provides information on the mechanical and chemical properties of zirconium castings.

This article begins with an overview of classes and applications of gray iron. It discusses the castability of gray iron in terms of section sensitivity and fluidity. The article provides information on the dimensions of prevailing sections recommended for gray irons and reviews the properties and specifications of test bar. Properties of gray iron, such as fatigue limit, pressure tightness, impact resistance, machinability, and dimensional stability, at both room and elevated temperature, are reviewed. Wear behavior of gray iron castings during sliding contact under conditions of normal lubrication is also discussed. The article evaluates the use of alloys and heat treatment to modify as-cast properties. It concludes with information on the physical properties of gray iron castings.

After solidification and cooling, further processing and finishing of the castings are required. This article describes the general operations of shakeout, grinding, cleaning, and inspection of castings, with particular emphasis on automation technology. It illustrates the vertical core knockout machine and the A-frame core knockout machine and lists the advantages and disadvantages of these machines. The article describes the general factors in automated or manual gate removal process. It concludes with discussion on the various types of inspection, such as the liquid penetrant inspection, pressure testing, radiographic inspection, magnetic particle inspection, and ultrasonic inspection.

This article begins with a description of the classes and grades of ductile iron. It discusses the factors affecting the mechanical properties of ductile iron. The article reviews the hardness properties, tensile properties, shear and torsional properties, compressive properties, fatigue properties, fracture toughness, and physical properties of ductile iron and compares them with other cast irons to aid the designer in materials selection. It concludes with information on austempered ductile iron.

This article provides a discussion on ten rules for the effective production of reliable castings. These 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.

This article reviews the graphite morphology, chemical composition requirements, castability, mechanical properties, and corrosion resistance of compacted graphite (CG) irons. It describes the factors affecting the mechanical properties of CG irons. The article also presents the advantages of CG irons.

Malleable iron is a cast ferrous metal that is initially produced as white cast iron and is then heat treated to convert the carbon-containing phase from iron carbide to a nodular form of graphite called temper carbon. This article provides a discussion on the melting practices, heat treatment, microstructure, production technologies, mechanical properties, and applications of ferritic, pearlitic, and martensitic malleable irons.

This article presents a discussion on the melting, pouring, and shakeout practices; composition control; molds, patterns, and casting design; heat treatment; and applications of different classes of nickel-chromium white irons and high-chromium white irons.

Repair welding is a necessary operation for most fabricators and can cost more than the price of the original component if performed improperly. This article provides a discussion on the repair welding of castings for ferrous and nonferrous materials. The discussion focuses on the surface preparation, weld repair process selection, joint selection, filler metal selection, weld repair considerations, deposition techniques, postweld heat treatment, and verification of weld repair quality.

This article discusses the requirements that are typically considered in designing a steel casting. It describes the materials selection that forms a part of process of meeting the design criteria. The article provides information on the material selection guide for five major design applications. It examines the attributes that are specific to the manufacturing of steel castings. The article concludes with information on the various nondestructive examination methods available for ensuring manufacturing quality and part performance in steel castings.

This article discusses the mechanical properties of carbon steels, low-alloy steels, wear-resistant steels, corrosion-resistant steels, heat-resistant steels, and common alloys at both room and elevated temperature. It also provides information on the corrosion-resistant and heat-resistant applications of the common alloys.

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 the 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 foundry alloys for specific casting applications. The article concludes with a discussion on the heat treatment practices and properties of aluminum casting alloys.

The properties of copper alloys occur in unique combinations found in no other alloy system. This article focuses on the major and minor alloying additions and their impact on the properties of copper. It describes major alloying additions, such as zinc, tin, lead, aluminum, silicon, nickel, beryllium, chromium, and iron. The article discusses minor alloying additions, including antimony, bismuth, selenium, manganese, and phosphorus. Copper alloys can be cast by many processes, including sand casting, permanent mold casting, precision casting, high-pressure die casting, and low-pressure die casting. The article provides information on the types of copper castings and tabulates the nominal chemical composition and mechanical properties of several cast alloys.