Search Results for wear-resistant applications

Structural applications for advanced ceramics include mineral processing equipment, machine tools, wear components, heat exchangers, automotive products, aerospace components, and medical products. This article begins with an overview of the wear-resistant applications and the parameters affecting wear of ceramics, namely, hardness, thermal conductivity, fracture toughness, and corrosion resistance. The next part of the article addresses temperature-resistant applications of advanced ceramics. Specific applications of ceramic materials addressed include cutting tools, pump and valve components, rolling elements and bearings, paper and wire manufacturing, biomedical implants, heat exchangers, adiabatic diesel engines, advanced gas turbines, and aerospace applications.

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

This article discusses the physical metallurgy of cast cobalt alloys with an emphasis on the crystallography, compositions, phases and microstructure, and properties. Cobalt alloys are cast by several different foundry methods. The article describes the argon-oxygen decarburization and continuous casting process. It provides information on castability and quality of the casted alloys. The article details the postcasting treatment, including heat treatment, hot isostatic pressing, and coatings. It summarizes the applications of cast cobalt alloys.

Cemented carbides belong to a class of hard, wear-resistant, refractory materials in which the hard carbide particles are bound together, or cemented, by a ductile metal binder. Cermet refers to a composite of a ceramic material with a metallic binder. This article discusses the manufacture, composition, classifications, and physical and mechanical properties of cemented carbides. It describes the application of hard coatings to cemented carbides by physical or chemical vapor deposition (PVD or CVD). Tungsten carbide-cobalt alloys, submicron tungsten carbide-cobalt alloys, and alloys containing tungsten carbide, titanium carbide, and cobalt are used for machining applications. The article also provides an overview of cermets used in machining applications.

Cobalt finds its use in various applications owing to its magnetic properties, corrosion resistance, wear resistance, and its strength at elevated temperatures. This article discusses the mining and processing of cobalt and cobalt alloys. It describes the types of cobalt alloys, including wear-resistant alloys, high-temperature alloys, corrosion-resistant alloys, and special-purpose alloys. The article provides data on the chemical composition, mechanical properties, and physical properties of these alloys. Further, it provides information on the uses of cobalt in superalloys, cemented carbides, magnetic materials, low-expansion alloys, and high-speed tool steels.

This article summarizes some general alloy groupings by application or major characteristics. The groupings include cast rotor, general-purpose, elevated-temperature, wear-resistant, moderate-strength, high-strength, and high-integrity die casting alloys and cast aluminum alloys bearings. A table lists selected applications for aluminum casting alloys.

Hardfacing refers to the deposition of a specially selected material onto a component in order to reduce wear in service as a preventative measure or return a worn component to its original dimensions as a repair procedure. This article provides information on various hardfacing materials, namely, iron-base overlays, chromium carbide-based overlays, nickel- and cobalt-base alloys, and tungsten carbide-based metal-matrix composite overlays. It discusses the types of hardfacing processes, such as arc welding processes, and laser cladded, oxyacetylene brazing and vacuum brazing processes. The arc welding processes include shielding metal arc welding, gas metal arc welding/flux cored arc welding, gas tungsten arc welding, submerged arc welding, and plasma transferred arc welding. The article also reviews various factors influencing the selection of the appropriate hardfacing for specific applications.

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.

The use of thermal spray coatings to restore worn surfaces has provided a significant improvement in surface performance due to improved wear resistance. This article discusses the general use of thermal spray coatings in reducing predominant types of wear, namely, abrasive wear, erosive wear, adhesive wear, and surface fatigue.

This article discusses the classification of wear based on the presence or absence of effective lubricants, namely, lubricated and nonlubricated wear. Variations in ambient temperature, atmosphere, load, and sliding speed, as well as variations in material bulk composition, microstructure, surface treatment, and surface finish of steel are also considered. The article discusses the types, wear testing, wear evaluation, and hardness evaluation of abrasive wear. It describes the selection criteria of steels for wear resistance. The article also describes the importance of hardness and microstructure as factors in resistance to wear. It provides a discussion on the resistance of various materials to wear in specific applications. The wear resistance of austenitic manganese steels is also discussed. The article discusses the applications of phosphate coatings, wear-resistant coatings, and ion implantation. It concludes with information on interaction of wear and corrosion.

This article reviews the factors influencing carburization to improve wear resistance of steel, such as operating temperature, cost, production volume, types of wear, and design criteria. It details the types of wear, namely abrasive wear and adhesive wear. The article discusses the characteristics of carburized steels that affect wear resistance, including hardness, microstructure, retained austenite, and carbides. It also describes the processing considerations for carburization of titanium.

Hardfacing is defined as the application of a wear-resistant material, in depth, to the vulnerable surfaces of a component by a weld overlay or thermal spray process Hardfacing materials include a wide variety of alloys, carbides, and combinations of these materials. Iron-base hardfacing alloys can be divided into pearlitic steels, austenitic (manganese) steels, martensitic steels, high-alloy irons, and austenitic stainless steel. The types of nonferrous hardfacing alloys include cobalt-base/carbide-type alloys, laves phase alloys, nickel-base/boride-type alloys, and bronze type alloys. Hardfacing applications for wear control vary widely, ranging from very severe abrasive wear service, such as rock crushing and pulverizing to applications to minimize metal-to-metal wear. This article discusses the types of hardfacing alloys, namely iron-base alloys, nonferrous alloys, and tungsten carbides, and their applications and advantages.

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.

Abrasive wear is a surface-damage process with material loss caused by hard asperities or abrasive particles occurring when two surfaces are sliding against each other. There are two types of abrasive wear: two-body abrasion and three-body abrasion. This article discusses the abrasive wear mechanism in ductile materials and commonly used testers for evaluating the resistance of materials to abrasive wear. The testers include pin-on-disk, block-on-ring, block-on-drum, and dry sand/rubber wheel abrasion tester. The article reviews the abrasion resistance of metallic materials, ceramic materials, and polymeric materials. It discusses factors that influence abrasive wear, including the environment, hardness, toughness, microstructure, and lubrication.

Cobalt is used as an alloying element in alloys for various applications. This article provides a detailed account of the metallurgy of cobalt-base alloys. It focuses on the compositions, properties, and applications of cobalt-base alloys, which include wear-resistant cobalt alloys, heat-resistant cobalt alloys, and cobalt-base corrosion-resistant alloys. The article also describes the heat treatments such as annealing and aging, for these alloys.

This article provides a general overview of physical and mechanical properties, alloy compositions, applications, and product forms of cobalt-base alloys as wear-resistant, corrosion-resistant, and/or heat-resistant materials. The discussion is largely focused on cobalt-base alloys for wear resistance, as this is the single largest application area of cobalt-base alloys.

Metallic nonelectrolytic alloy coatings produced from aqueous solutions are commercially used in several industries, including electronics, aerospace, medical, oil and gas production, chemical processing, and automotive. Nonelectrolytic coating systems use two types of reactions to deposit metal onto a part: electroless and displacement. This article explains the various types of electroless and dispersion alloy coating systems. It provides information on the processing of parts, process control, deposit analysis, and equipment used for coating nonelectrolytic displacement alloys. The article concludes with a discussion on the safety and environmental concerns associated with nonelectrolytic deposition processes.

In the friction surfacing process, a rotating consumable is brought into contact with a moving substrate, which results in a deposited layer on the substrate. This article describes the process as well as the equipment used. It also provides information on the applications of the friction surface process.

Tribology is the science and technology of interacting surfaces in relative motion or, the study of friction, wear, and lubrication. This article focuses on friction and wear processes that aid in the evaluation and selection of materials, for polymers and some composites used in friction and wear applications. It provides information on friction, types of wear, and lubrication. The article includes a brief description of the friction and wear test methods, laboratory-scale friction, and wear testing, usually performed either to rank the performance of candidate materials for an application or to investigate a particular wear process. It describes the wear tests conducted with/without abrasives and explains the concept of PV limit (where P is contact pressure and V is velocity). The article concludes with references and tables of friction and wear test data for polymeric materials.

Cemented carbides, best known for their superior wear resistance, have a range of industrial uses more diverse than that of any other powder metallurgy product including metalworking and mining tools and wear-resistant components. This article discusses raw materials and manufacturing methods used in the production of cemented carbides, the physical and mechanical properties of carbides, and wear mechanisms encountered in service. Emphasis is placed on tungsten carbide-cobalt (WC-Co) or tungsten carbide-nickel (WC-Ni) materials as used in nonmachining applications. Nominal composition and properties of representative cemented carbide grades and their applications are listed in a table.