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Scratch Resistance (scratch + resistance)
Selected AbstractsA New Analytical Model for Estimation of Scratch-Induced Damage in Brittle SolidsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2007Xiaoning Jing Scratch tests are of fundamental interest both for understanding machining-induced damage and for evaluating the scratch resistance of brittle materials. An improved blister field model for the scratch process is proposed where the blister field strength is explicitly determined in terms of the material properties, loading conditions, and geometry of the scratch tool. Additionally, one new expanding cylindrical cavity model is implemented to estimate the plastic zone size surrounding the scratch groove. A quantitative evaluation of the damage zone size is conducted by combining the above two models. The predicted damage zone sizes are in good agreement with the results available elsewhere in literature. [source] Characterization of grooves in scratch resistance testingPOLYMER ENGINEERING & SCIENCE, Issue 10 2008Witold Brostow For a number of polymers with different chemical structures and different properties we have determined scratch resistance and sliding wear (15 scratches along the same groove). We have measured cross section areas after scratching, namely the groove and side top-ridge areas. Nanohardness after scratching was determined using nanoindentation testing both inside and outside the scratching and sliding wear grooves. Three modes of sliding wear are seen: plowing, cutting with debris formation, and densification. The dominating mode depends on the material and is reflected in nanohardness. In polycarbonate (PC) the nanohardness inside and outside the groove are practically the same; the indenter just plows the material aside without debris formation or densification. Thus, the old measure of wear as the weight of the debris formed is not usable for PC; grooves are present but there is no loosened material. By contrast, in brittle materials such as polystyrene there is debris formation and nanohardness inside the groove decreases after 15 scratching runs. A third type of behavior is seen in polyethylene and polypropylene, namely densification caused by scratching; as a result, nanohardness inside the groove increases after 15 passes of the indenter. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers [source] Roles of additives in scratch resistance of high crystallinity polypropylene copolymersPOLYMER ENGINEERING & SCIENCE, Issue 1 2001C. Xiang Scratch behavior in neat and talc-filled high crystallinity polypropylene (PP) copolymers containing various additives is investigated using a cosntant load scratch test and two types of indentation tests (Rockwell and Shore D). The talcfilled PP copolymer exhibits high scratch visibilityand scratch depth. The addition of a nucleating agent or lubricant improves the scratch resistance of the talc-filled PP copolymer. Differential scanning calorimetry, scanning electron microscopy and attenuated total reflectance Fourier transform infrared spectroscopy are used to characterize crystallinity morphology and scratch mechanisms in PP systems. It is found that the scratch resistance of the PP copolymer systems investigated, in terms of scratch depth and scratch visibility, depends mainly on the fracture features generated during the scratch process. The influences of talc, nucleating agent and lubricant on the scratch behavior of PP are discussed. [source] | ||||||||||