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Palmqvist Method
The Palmqvist method, or the Palmqvist toughness test, (after Sven Robert Palmqvist) is a common method to determine the fracture toughness for cemented carbides. In this case, the material's fracture toughness is given by the critical stress intensity factor In fracture mechanics, the stress intensity factor () is used to predict the stress state ("stress intensity") near the tip of a crack or notch caused by a remote load or residual stresses. It is a theoretical construct usually applied to a h ... KIc. Approach The Palmqvist-method uses the lengths of the cracks from a number of Vickers indentions to determine the fracture toughness. The Palmqvist fracture toughness is given by :K_ = 0.0028\sqrt\sqrt in units of MPa\sqrt{\text{m, where HV is the Vickers hardness in N/mm2 (or MPa) (i.e., 9.81 x numerical HV), P is the indentation load in N (typically 30 kgf is used) and T is the total crack length (mm) after application of the indenter. Notes Materials testing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture Toughness
In materials science, fracture toughness is the critical stress intensity factor of a sharp crack where propagation of the crack suddenly becomes rapid and unlimited. A component's thickness affects the constraint conditions at the tip of a crack with thin components having plane stress conditions and thick components having plane strain conditions. Plane strain conditions give the lowest fracture toughness value which is a material property. The critical value of stress intensity factor in mode I loading measured under plane strain conditions is known as the plane strain fracture toughness, denoted K_\text. When a test fails to meet the thickness and other test requirements that are in place to ensure plane strain conditions, the fracture toughness value produced is given the designation K_\text. Fracture toughness is a quantitative way of expressing a material's resistance to crack propagation and standard values for a given material are generally available. Slow self- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cemented Carbide
Cemented carbides are a class of hard materials used extensively for cutting tools, as well as in other industrial applications. It consists of fine particles of carbide cemented into a composite by a binder metal. Cemented carbides commonly use tungsten carbide (WC), titanium carbide (TiC), or tantalum carbide (TaC) as the aggregate. Mentions of "carbide" or "tungsten carbide" in industrial contexts usually refer to these cemented composites. Most of the time, carbide cutters will leave a better surface finish on a part and allow for faster machining than high-speed steel or other tool steels. Carbide tools can withstand higher temperatures at the cutter-workpiece interface than standard high-speed steel tools (which is a principal reason enabling the faster machining). Carbide is usually superior for the cutting of tough materials such as carbon steel or stainless steel, as well as in situations where other cutting tools would wear away faster, such as high-quantity product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Organization For Standardization
The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in Article 3 of the ISO Statutes. ISO was founded on 23 February 1947, and (as of November 2022) it has published over 24,500 international standards covering almost all aspects of technology and manufacturing. It has 809 Technical committees and sub committees to take care of standards development. The organization develops and publishes standardization in all technical and nontechnical fields other than electrical and electronic engineering, which is handled by the IEC.Editors of Encyclopedia Britannica. 3 June 2021.International Organization for Standardization" ''Encyclopedia Britannica''. Retrieved 2022-04-26. It is headquartered in Geneva, Switzerland, and works in 167 countries . The three official languages of the ISO are English, F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sven Robert Palmqvist
Sven (in Danish and Norwegian, also Svend and also in Norwegian most commonly Svein) is a Scandinavian first name which is also used in the Low Countries and German-speaking countries. The name itself is Old Norse for "young man" or "young warrior". The original spelling in Old Norse was ''sveinn''. Over the centuries, many northern European rulers have carried the name including Sweyn I of Denmark (Sven Gabelbart). An old legend relates the pagan king Blot-Sven ordered the execution of the Anglo-Saxon monk Saint Eskil. In medieval Swedish, "sven" (or "sven av vapen" (sven of arms)) is a term for squire. The female equivalent, Svenja, though seemingly Dutch and Scandinavian, is not common anywhere outside of German-speaking countries. Sven can also be spelled with W, Swen, but is pronounced as Sven. The Icelandic version of Sven/Svend is Sveinn (); the Faroese version is Sveinur (). Entertainment and music * Sven Einar Englund, Finnish composer * Sven Epiney, Swiss tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stress Intensity Factor
In fracture mechanics, the stress intensity factor () is used to predict the stress state ("stress intensity") near the tip of a crack or notch caused by a remote load or residual stresses. It is a theoretical construct usually applied to a homogeneous, linear elastic material and is useful for providing a failure criterion for brittle materials, and is a critical technique in the discipline of damage tolerance. The concept can also be applied to materials that exhibit ''small-scale yielding'' at a crack tip. The magnitude of depends on specimen geometry, the size and location of the crack or notch, and the magnitude and the distribution of loads on the material. It can be written as: :K = \sigma \sqrt \, f(a/W) where f(a/W) is a specimen geometry dependent function of the crack length, , and the specimen width, , and is the applied stress. Linear elastic theory predicts that the stress distribution (\sigma_) near the crack tip, in polar coordinates (r,\theta) with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vickers Hardness Test
The Vickers hardness test was developed in 1921 by Robert L. Smith and George E. Sandland at Vickers Ltd as an alternative to the Brinell method to measure the hardness of materials. The Vickers test is often easier to use than other hardness tests since the required calculations are independent of the size of the indenter, and the indenter can be used for all materials irrespective of hardness. The basic principle, as with all common measures of hardness, is to observe a material's ability to resist plastic deformation from a standard source. The Vickers test can be used for all metals and has one of the widest scales among hardness tests. The unit of hardness given by the test is known as the Vickers Pyramid Number (HV) or Diamond Pyramid Hardness (DPH). The hardness number can be converted into units of pascals, but should not be confused with pressure, which uses the same units. The hardness number is determined by the load over the surface area of the indentation and not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Materials Testing
Materials testing is used to assess product quality, functionality, safety, reliability and toxicity of both materials and electronic devices. Some applications of materials testing include defect detection, failure analysis, material development, basic materials science research, and the verification of material properties for application trials. This is a list of organizations and companies that publish materials testing standards or offer materials testing laboratory services. International organizations for materials testing These organizations create materials testing standards or conduct active research in the fields of materials analysis and reliability testing. * American Association of Textile Chemists and Colorists (AATCC) * American National Standards Institute (ANSI) * American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) * American Society of Mechanical Engineers (ASME) * ASTM International * Federal Institute for Materials Research and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
