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Hassan Beigee, Hamid Reza | 2015

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 47679 (07)
  4. University: Sharif University of Technology
  5. Department: Materials Science and Engineering
  6. Advisor(s): Ghorbani, Mohammad
  7. Abstract:
  8. Phosphating is one of the most procedures as a final surface treatment or pre-treatment (lubrication and Infrastructure color) is done on ferrous and nonferrous alloys. Phosphate coating on the wire drawing, increase speed of drwing, increase die life, increased resistance to abrasion caused by the friction reduction, reduced maintenance costs and improved surface appearance are combustible and conditions. The aim of this study was to evaluate the effects of variables such as temperature, pH bath, the coating bath components concentration on coating properties and optimize calcium zinc phosphate coating on steel wire, for better lubrication and decrease friction in the wire drawing process. Scanning electron microscopy, X-ray diffraction analysis and wear tests in order to evaluate the morphology of coating, coating structure and wear resistance of the coating was applied. The results of this study showed that by adding calcium ions to phosphating bath, cover with a less porous, fine-grained morphology and low coefficient of friction is created. The use of calcium ions to improve the wire drawing process is effective and causes friction coefficient of around 0.92 (for steel uncoated) to 0.47 for one cationic zinc phosphate coating and 0.21 for zinc Calcium phosphate coating. The structure also includes cover for optimal Hopite phase (plate shape) and phase Scholzite (flower shape) is.be. Based on the results, the best time is 10 minutes and increase time working phosphate coating crystal growth and dissolution of crystals is too much. The coating thickness of about 7 microns, and optimized for coating weight about 18 gr / m2
  9. Keywords:
  10. Friction Coefficient ; Lubrication ; Phosphating ; Low Carbon Steel Wire ; Two Cathionic Phosphate Coating ; Zinc-Calsium Lubricant

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