Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Author: search.filters.author.Medabalimi, S.Subject: search.filters.subject.High temperature wear

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Effect of Microwave Hybrid Heating on High-Temperature Adhesive Wear Behavior of High-Velocity Oxygen Fuel-Sprayed WC-CrC-Ni and WC-Co/NiCrFeSiB Coatings
    (Springer, 2023) Medabalimi, S.; Ananthu, M.R.; Gudala, S.; Ramesh, M.R.
    HVOF-processed coatings are chemically inhomogeneous and are not metallurgically bonded to the substrate. As a result, components coated with HVOF experience considerable material degradation during sliding wear. Microwave hybrid heating (MHH) is a novel surface modification technique for modifying the as-sprayed properties of the coating. Hence, this paper investigates and compares the wear and frictional behavior of HVOF as-sprayed coatings against MHH samples of WC-CrC-Ni and WC-Co/NiCrFeSiB coatings at elevated temperatures. MHH had a significant impact on wear rate and coefficient of friction by optimizing the porosity, integrated oxide phases and intersplat cohesion strength of the coatings. A modified domestic oven was used to perform MHH on HVOF-coated samples for 5 min at 1200 °C. Wear tests were performed using a pin-on-disk tribometer from room temperature to 200, 400, and 600 °C with Al2O3 disk as a counterface. SEM/EDS and XRD were utilized to examine the microstructural characterization of the coatings and substrate. Both the coatings showed higher wear resistance than the substrate at all temperatures. The WC-Co/NiCrFeSiB coating produced an oxide layer on the worn surfaces and integrated WC, CoWO4, and Fe2SiO4 splats, enhancing wear resistance. The MHH WC-CrC-Ni coating formed Cr2O3 and NiWO4 phases on the worn surfaces, increasing the intersplat cohesion strength between matrix and carbide splats, lowering the overall wear rate. After MHH, the wear rate of a substrate and WC-CrC-Ni coating was 3.5 and 1.12 times more at room temperature and 8.07 and 2.92 times more at 600 °C than WC-Co/NiCrFeSiB coating. © 2022, ASM International.
  • No Thumbnail Available
    Item
    Microstructure and elevated temperature wear behavior of HVOF-sprayed SS304L stainless-steel coating
    (Springer Nature, 2025) Medabalimi, S.; Gudala, S.; Rokkala, U.; Hebbale, A.M.; Ramesh, M.R.
    The paper aims to investigate the performance of the SS304L stainless steel coating on wear properties by varying load, temperature and velocity. Stainless-steel coatings were fabricated by high-velocity oxy-fuel spraying (HVOF) on superfer800. Surface morphology, elemental distribution and phase analysis were expressed by SEM, EDS, and XRD, respectively. The porosity, average surface roughness, and average microhardness of HVOF stainless steel coating are 2%, 7 µm, and 1167 ± 54 HV0.3, respectively. The wear rate of stainless-steel coating is 0.5 × 10?3 mm3/m at 600 °C with 20 N loads, which is about 16 times lower than the substrate. Adhesion and abrasion are the main wear mechanisms of HVOF stainless steel coatings during high-temperature tests. Comparing to superfer800 substrate, stainless steel coatings showed superior wear resistance at all the loads, temperature and velocities. © The Author(s) 2025.