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Thin Films for Cutting Tools
Published in Fredrick Madaraka Mwema, Tien-Chien Jen, Lin Zhu, Thin Film Coatings, 2022
Fredrick Madaraka Mwema, Tien-Chien Jen, Lin Zhu
The materials for HSM tools should possess properties that can withstand operating conditions such as temperature and applied forces. Some of these materials include cemented carbides (including other materials coated with carbides as they have improved hardness), polycrystalline diamond, ceramics, and polycrystalline cubic boron nitride.
Materials
Published in Ansel C. Ugural, Youngjin Chung, Errol A. Ugural, Mechanical Engineering Design, 2020
Ansel C. Ugural, Youngjin Chung, Errol A. Ugural
Selection of a material that has good resistance to wear and erosion very much depends on the hardness and the surface condition. Hardness is the ability of a material to resist indentation and scratching. The kind of hardness considered depends on the service requirements to be met. For example, gears, cams, rails, and axles must have a high resistance to indentation. In mineralogy and ceramics, the ability to resist scratching is used as a measure of hardness. The indentation hardness, generally used in engineering, is briefly discussed in this section.
Rock properties with respect to wear
Published in H.J.R. Deketh, Wear of Rock Cutting Tools, 2020
The results of hardness tests depend not only on the nature of the material but also on the nature of the test itself. Tests, like the Vickers or Brinell hardness tests, which take the indentation diameter of an imprint of a sphere or pyramid, pressed with a prescribed load and period of time into the test body, are, as a measure of hardness, completely different from tests like Rosiwal’s hardness test, which uses the loss of material after grinding the test body with abrasive powder as a measure of hardness or the Mohs hardness test, which uses the ability of one mineral to scratch another as a measure of hardness. Diamond, which cannot be scratched by any other mineral and is thus the hardest, has a hardness value of 10. Talc, which cannot scratch any other mineral, has a value of 1. In Table 2 the hardnesses of some minerals according to three test methods of different nature are listed (Verhoef et al. 1990). It can be seen that the hardness scales are not linearly related.
Composite material from waste poly (ethylene terephthalate) reinforced with glass fiber and waste window glass filler
Published in Green Chemistry Letters and Reviews, 2023
Biruk Gedif Worku, Tessera Alemneh Wubieneh
Hardness is the resistance of a material to deformation, particularly permanent deformation, indentation, or scratching. The Rockwell, Brinell, and Viker hardness are the most common testing techniques. For this research, Rockwell hardness testing (BROOKS Hardness Tester MAT10/RAB) is used. As shown in Figure 5(a) Rockwell hardness testing, (b) the gauge position before minor load, and (c) the gauge position after minor load. The specimen is prepared by fulfilling the requirement prescribed by the ASTM E384 standards (23). Since the order of the numbers is reversed on the dial gauge, a shallow impression on a hard material will result in a high number while a deep impression on a soft material will result in a low number. In this paper B scale (1/16 in. ball indenter and 100 kg load) with the normal tester was used.
Influence of surface roughness on concrete nanoindentation
Published in European Journal of Environmental and Civil Engineering, 2020
Typical NI tests consist of establishing contact between a sample and an indenter of which the mechanical properties and geometry are known. During indentation, the force acting on the indenter as the control variable and the corresponding penetration depth are continuously applied and recorded. Commonly, an indentation load-depth curve with loading, holding and unloading periods is used. According to the indentation load-depth curve (see Figure 3), the stiffness, the hardness and the indentation modulus can be calculated respectively. Commonly, the indentation modulus, representing the elastic properties of material and indenter tip, is related to the elastic modulus and Poisson’s ratio of the local material for a homogeneous isotropic elastic material (Fischer-Cripps, 2002; Oliver & Pharr, 1992). When the modulus of different phases in concrete is calculated by statistical nanoindentation method, the values of Poisson’s ratio of different phases are needed. In the course of calculation, according to the results of literature (Constantinides & Ulm, 2004; Sorelli et al., 2008), the values of different phases are shown in Table 2. The hardness is related to the yield strength of the local material, and the hardness to yield strength ratio depends on the material type.
Tribological Performance of Si3N4-PTFE Composites Prepared by High-Pressure Compression Molding
Published in Tribology Transactions, 2020
Dapeng Gu, Shouyao Liu, Suwen Chen, Kefeng Song, Bingchao Yang, Deng Pan
Hardness is normally regarded as one of the key factors that impacts wear resistance (34). However, various hardness test methods suit different materials and are not directly comparable. Therefore, Vickers hardness and shore hardness are respectively introduced as hardness testing methods. The hardnesses of 100(1-x)Si3N4-100xPTFE-EP composites and 100(1-x)Si3N4-100xPTFE composites are reported in Figure 5. The values of Vickers hardness and shore hardness decrease with an increase in PTFE mass fraction. Furthermore, the shore hardness of 100(1-x)Si3N4-100xPTFE-EP composites is almost 10 HD higher than that of 100(1-x)Si3N4-100xPTFE composites under the same PTFE mass fraction. The dispersion of EP in 100(1-x)Si3N4-100xPTFE-EP composites is a 3D network structure (as seen in Figure 2a), connecting and fixing Si3N4 and PTFE particles. Hence, the deformation caused by external forces can be decreased.