Articles written in Sadhana
Volume 45 All articles Published: 23 July 2020 Article ID 0187
The present sol-gel processes present a surface modification technique for improving the sliding wear resistance characteristics of metallic materials of 2024-T351 aluminum alloy. With the help of dip-coating methods, seven weight% yttria stabilized zirconia (7YSZ) as a top-coat is applied over the air plasma sprayedbond-coated materials, CoNiCrAlY, on aluminum alloys. Thereafter, coating thickness is measured using an optical microscope. Further, sliding wear tests are performed on Pin-On-Disc Friction and Wear test rig as per L16 orthogonal arrays of Taguchi method. Investigations revealed temperature as the most influencing parameter for uncoated samples while temperature and applied load, both for coated samples. In comparison to base metallic alloys, sol-gel derived YSZ coating on the AA2024 surface exhibited better wear resistance, resultedinto the reduction of wear rate.
Volume 46 All articles Published: 6 July 2021 Article ID 0133
Air plasma sprayed (APS) 7weight percent yttria stabilized zirconia (7YSZ) typical thermal barrier coatings are commonly used in aero engine components to protect against thermal fatigue, corrosion, erosion, corrosion-erosion and oxidation phenomenon. In spite of extensive industrial application of 7YSZ coatings, very few works are there on erosion wear performance and its mechanisms on these coatings. In the present work, comparative inspection of the erosion wear behaviors of air plasma sprayed 7YSZ thermal barrier coatings and dip-coated sol-gel processed 7YSZ thermal barrier coatings are carried out. For the sake of comparison erosion of uncoated Inconel 800 superalloys substrate was also studied. Erosion tests were conducted on air jet erosionconditions with alumina erodent materials and process parameters determined as per Taguchi design of experiments at room and high temperature of 850˚C. Erosion wear resistance of non-conventional dip-coating of sol-gel derived 7YSZTBC was found better in comparison to conventional APS YSZ coatings.