Search Results for cement carbides

This article discusses the manufacturing steps and compositions of cemented carbides, as well as their microstructure, classifications, applications, and physical and mechanical properties. It provides information on new tool geometries, tailored substrates, and the application of thin and hard coatings to cemented carbides by chemical vapor deposition and physical vapor deposition. The article also discusses tool wear mechanisms and the methods available for holding the carbide tool.

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 soft and ductile metal binder. The performance of cemented carbide as a cutting tool lies between that of tool steel and cermets. Almost 50% of the total production of cemented carbides is used for nonmetal cutting applications. Their properties also make them appropriate materials for structural components, including plungers, boring bars, powder compacting dies and punches, high-pressure dies and punches, and pulverizing hammers. This article discusses the manufacture, microstructure, composition, classifications, and physical and mechanical properties of cemented carbides, as well as their machining and nonmachining applications. It examines the relationship between the workpiece material, cutting tool and operational parameters, and provides suggestions to simplify the choice of cutting tool for a given machining application. It also examines new tool geometries, tailored substrates, and the application of thin, hard coatings to cemented carbides by chemical vapor deposition and physical vapor deposition. It discusses the tool wear mechanisms and the methods available for holding the carbide tool. The article is limited to tungsten carbide cobalt-base materials.

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.

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.

Cemented carbides are extremely important in corrosion conditions in which high hardness, wear resistance, or abrasion resistance is required. This article describes the effect of binder composition and carbide addition on corrosion behavior of cemented carbides. It lists the examples of their uses in corrosion applications. The article provides information on the selection of cemented carbides for corrosion applications and tabulates the corrosion resistance of cemented carbides in various media. It expounds the oxidation resistance of cemented carbides and presents some tips to improve the properties of tungsten carbide cutting tools. The article also details the coating materials and coating processes of cemented carbides.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of one specific type of cemented carbide, tungsten carbide. It also assists in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the brittle fracture, transgranular fracture, intergranular fracture, and crack propagation of the tungsten carbide.

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.

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.

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.

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.

Tungsten, molybdenum, and cemented carbide parts can be produced using several additive manufacturing technologies. This article classifies the most relevant technologies into two groups based on the raw materials used: powder-bed methods, such as selective laser melting, electron beam melting, and binder jet three-dimensional (3-D) printing, and feedstock methods, such as fused-filament fabrication and thermoplastic 3-D printing. It discusses the characteristics, processing steps, properties, advantages, limitations, and applications of these technologies.