Search Results for round disks

Trepanning is used in at least four distinct production applications: round disks, large shallow through holes, circular grooves, and deep holes. This article provides an overview of the first three applications. It describes the machines, tools, techniques, and cutting fluids used for deep-hole trepanning. The article contains a table that lists speeds and feeds for the deep-hole trepanning of various steels with high-speed tool steels and carbide tools.

This article presents the three levels of investigations of distortion engineering. On Level 1, the parameters and variables influencing distortion in every manufacturing step must be identified. More than 200 parameters can affect distortion. The design of experiments approach allows for the investigation of larger numbers of parameters by a limited number of samples, and can be structured into system analysis, test strategy, test procedure, and test evaluation. Level 2 focuses on understanding the distortion mechanisms by using the concept of distortion potential and its carriers. Distortion engineering aims to compensate distortion using the so-called compensation potential (Level 3). Level 3 discusses the measures to improve homogeneity, and respectively the symmetry, of the carriers of the distortion potential. The article also discusses the compensation of the resulting size and shape changes of the existing asymmetries by well-directed insertions of additional inhomogeneity/asymmetries in one or more of the distributions of the carriers.

This article provides the basics of overall quench process distortion. It describes the influence of quenching processes on the generation of distortion. Examples for the distortion behavior of different types of components are presented. Then, comparisons between different quenching processes are provided. The article presents some possibilities for minimization of shape changes by the quenching process itself. Several suggestions are given for quenching processes in evaporating fluids. An example is provided for out-of-roundness reduction for rings by well-defined inhomogeneous quenching in a gas nozzle field. Another example shows how intensive and high-speed quenching can help to reduce the bending of shafts with an asymmetrical cross-section. The last example shows the result when external loads and nonsymmetric quenching act together. The article also presents test samples for the judgment about distortion potential arising from heat treatment equipment.

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.

Electron beam machining (EBM) uses a focused beam of high-velocity electrons to remove material. This article provides a description of equipment used for EBM and discusses the process characteristics, applications, advantages, and disadvantages of electron beam drilling.

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.

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.

Bars, structural shapes, and long parts are straightened by bending, twisting, or stretching. This article describes the straightening of bars, shapes, and long parts by material displacement, heating, and presses. It explains the process of parallel-roll straightening, automatic press roll straightening, moving-insert straightening, parallel-rail straightening, and epicyclic straightening. The article concludes with a discussion on straightening in bar production.

Finishing refers to a wide variety of processes that generally involve material removal in one form or another to generate surfaces with specific geometries, tolerances, and functional or decorative characteristics. This article discusses four major finishing methods, namely, abrasive machining, electropolishing, mass finishing, and shot peening. In each case, it describes subtypes, process variations, and the associated equipment.

This article addresses the important variables in erosion, such as particle impact velocity; particle impact angle; particle size, shape, and material; and ambient temperature. It describes four erosion test methods: the gas-blast method, a method using a centrifugal accelerator test rig, the wind-tunnel test, and the whirling arm test. The article also details the various test methods used to measure impact velocity of particle and data analysis and interpretation of these four methods.

This article focuses on friction and wear of automotive and aircraft brakes. It provides a comparison of friction and wear behaviors, frictional characteristics, and frictional performance of the friction materials. The article describes the components of brake friction materials and the classifications of brake lining materials. It discusses the effect of formulation compositions and manufacturing processes and the effect of braking operation conditions. The article provides information on aircraft brake linings, which operate under a wide range of kinetic energy conditions. The morphology effect of graphite on automotive brake drum and disk is explained. The article also describes the characteristics of specific wear rates for both normal and local cast iron in automotive brake drums and disk rotors. It provides information on noises, vibrations, and harshness caused by brake pads. The article concludes with information on physical and chemical testing of brakes and toxicity of brake formulation and regulations.

Wear, a form of surface deterioration, is a factor in a majority of component failures. This article is primarily concerned with abrasive wear mechanisms such as plastic deformation, cutting, and fragmentation which, at their core, stem from a difference in hardness between contacting surfaces. Adhesive wear, the type of wear that occurs between two mutually soluble materials, is also discussed, as is erosive wear, liquid impingement, and cavitation wear. The article also presents a procedure for failure analysis and provides a number of detailed examples, including jaw-type rock crusher wear, electronic circuit board drill wear, grinding plate wear failure analysis, impact wear of disk cutters, and identification of abrasive wear modes in martensitic steels.

Engineered components fail predominantly in four major ways: fracture, corrosion, wear, and undesirable deformation (i.e., distortion). Typical fracture mechanisms feature rapid crack growth by ductile or brittle cracking; more progressive (subcritical) forms involve crack growth by fatigue, creep, or environmentally-assisted cracking. Corrosion and wear are another form of progressive material alteration or removal that can lead to failure or obsolescence. This article primarily covers the topic of abrasive wear failures, covering the general classification of wear. It also discusses methods that may apply to any form of wear mechanism, because it is important to identify all mechanisms or combinations of wear mechanisms during failure analysis. The article concludes by presenting several examples of abrasive wear.

Semisolid metal (SSM) processing is a special die casting process, where partially solidified metal slurry is injected into a die cavity to form die cast components. This article discusses the flow behavior of an SSM slurry with emphasis on viscosity, rheological behavior, and yield stress. It illustrates the microstructural formation of semisolids under forced convection. The article concludes with an illustration that compares two SSM processes, namely, thixocasting and rheocasting.

This article focuses on the effects of mechanical plasticity on workability; that is, process control of localized stress and strain conditions to enhance workability. It describes the nature of local stress and strain states in bulk forming processes, leading to a classification scheme, including testing procedures and specific process measurements, that facilitate the application of workability concepts. Using examples, the article applies these concepts to forging, rolling, and extrusion processes. The stress and strain environments described in the article suggest that a workability test should be capable of subjecting the material to a variety of surface strain combinations. By providing insights on fracture criteria, these tests can be used as tools for troubleshooting fracture problems in existing processes, as well as in the process development for new product designs.

The article provides a discussion on the parameters influencing abrasive wear and the elements and standards of abrasion wear tests. It emphasizes the general test procedures, advantages, and limitations of various types of abrasive wear testing. Wear testing for scratch wear, dry abrasion against fixed particles, dry abrasion against loose particles, wet abrasion against fixed or loose particles, gouging-abrasion, small particle erosion, impact abrasion, slurry abrasion, and microabrasion, are also discussed.

Radial forging is a process performed with four dies arranged in one plane that can act on a piece simultaneously. This article explains the types of radial forgings and describes the advantages and disadvantages of radial forging over open-die cogging/forging. The article discusses the parameters involved in product shape control. It also provides examples that illustrate the versatility and capabilities of the radial forge machine.