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5285 |
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Thursday, June 08, 2017, Hall 26 4:40 PM Wear & Corrosion Protection |
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Development of HVOF-sprayed TiC-FeCrAl coatings |
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Giovanni Bolelli / Department of Engineering "Enzo Ferrari", University of Modena and Reggio Emilia, Italy Luca Lusvarghi/ Department of Engineering Enzo Ferrari , University of Modena and Reggio Emilia, Italy Pietro Puddu/ Department of Engineering Enzo Ferrari , University of Modena and Reggio Emilia, Italy Rinaldo Rigon/ Ecor Research SpA, Italy Paolo Sassatelli*/ University of Modena and Reggio Emilia, Italy |
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This study is motivated by the need to devise sustainable alternatives to conventional hardmetal compositions based on WC-Co(Cr) and Cr3C2-NiCr for wear and corrosion protection of mechanical components. W and Co are indeed often regarded as critical raw materials , due to their scarce, insecure supply coupled to their strategic economic importance. Moreover, health and safety issues are posed by the handling of powder materials containing Ni (a suspect inhalation carcinogen and a toxic, allergenic substance), Co (a cat. IB inhalation carcinogen), or WC-Co mixtures (where the synergistic effect between the two constituents causes harmful reactions when inhaled). In this study, a TiC-based hardmetal powder with a Fe-alloy matrix, free of critical or health-hazardous materials, was synthesized by ball milling and deposited onto stainless steel plates by a H2-fuelled Diamond Jet 2600 HVOF torch, under various deposition conditions. The microstructure, phase composition and micromechanical properties of the coatings were characterized by (FEG)-SEM + EDX, XRD, micro- and nano-indentation techniques, respectively. Rotating ball-on-disk tests against Al2O3 spheres (at room temperature and at 400 °C) and steel-wheel abrasion tests (using corundum particles) were respectively employed to investigate the sliding and abrasive wear resistance of the coatings. The results were compared to those of reference HVOF-sprayed WC-10Co4Cr and Cr3C2-25NiCr coatings, and the wear mechanisms were assessed by microstructural investigation of wear scars and wear debris by SEM+EDX and micro-Raman spectroscopy. |