Tribomechanical insight into carbide-laden hybrid suspension-powder plasma-sprayed Tribaloy T400 composite coatings
2020 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 396, article id 125957Article in journal (Refereed) Published
Abstract [en]
Tribaloy T400 (CoCrMoSi) caters to heavy-duty industrial tribological demands, but exhibits low fracture toughness with compromised resistance to crack propagation owing to the disparity in % Laves phases. In response to this limitation, hybrid suspension-powder plasma-sprayed novel Cr3C2 (d50 of 3.8 ÎŒm)/TiC (d50 of 2.2 ÎŒm) reinforced T400 (average powder size of 10â45 ÎŒm) coatings are deposited on grit-blasted SSAB Domex®350 LA steel. Continuous, adherent and co-existing lamellar T400-carbide coatings of 100 ÎŒm thickness were revealed in microstructure analysis. Intermetallic CoMoSi/Co3Mo2Si Laves and eutectic Co7Mo6/Co2Mo7 phases in T400 in addition to Cr3C2/TiC characteristic phases are confirmed via X-ray diffraction study. T400-Cr3C2 and T400-TiC have exhibited enhancement in elastic modulus (E) by 39%, and 36%, Vickers hardness (Hv) by 68%, and 82.5%; which consequently elucidates the augmentation in plasticity index (re) by 15.7% and 26.7%, and the drop in maximum displacement amplitude (hmax) by 14.9% and 19.8%, respectively, in T400-Cr3C2 and T400-TiC with reference to T400 (E of 135.2 GPa, Hv of 6.3 GPa, re = 0.318, and hmax = 1947 nm). A subsequent surmised fretting Hertzian contact diameter in T400-Cr3C2 ( 95.43 ÎŒm)/T400-TiC ( 96.1 ÎŒm) evaluated against T400 ( 106.9 ÎŒm) from optical profilometry indicates an improved damage tolerance. A contact area-based wear model, proposed herein to assess wear on a rough surface, further justifies the wear characteristics. Furthermore, synergistic L929 cell viability is recorded in T400-Cr3C2 (by 46%) and T400-TiC (by 30%) when compared with the control (+ve) disk. To conclude, suspension-powder plasma-sprayed T400-Cr3C2/T400-TiC composite coatings allude potential application in wear-resistant articulating surfaces by eliciting significantly enhanced micro-hardness through refined microstructure retention, improved fretting wear resistance by forming protective tribofilm, and augmented cellular response. © 2020 Elsevier B.V.
Place, publisher, year, edition, pages
2020. Vol. 396, article id 125957
Keywords [en]
Carbides; Cobalt compounds; Composite coatings; Fracture toughness; Microhardness; Microstructure; Molybdenum compounds; Plasma jets; Powder coatings; Silicon; Silicon compounds; Sprayed coatings; Titanium carbide; Tribology; Vickers hardness; Wear of materials; Wear resistance, Articulating surfaces; Maximum displacement; Microstructure analysis; Optical profilometry; Plasticity indices; Refined microstructure; Wear characteristics; X-ray diffraction studies, Plasma spraying, Hybrid suspension-powder plasma spray, Fretting wear
National Category
Manufacturing, Surface and Joining Technology
Identifiers
URN: urn:nbn:se:hv:diva-15733DOI: 10.1016/j.surfcoat.2020.125957ISI: 000540175000023Scopus ID: 2-s2.0-85085643022OAI: oai:DiVA.org:hv-15733DiVA, id: diva2:1460342
Note
Funders;DST (Department of Science and Technology), Govt. of India(DST/SJF/ETA-02-2016-17)
2020-08-242020-08-242021-04-19Bibliographically approved