Thermal barrier coatings with novel architectures for diesel engine applicationsShow others and affiliations
2020 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 396, article id 125950Article in journal (Refereed) Published
Abstract [en]
The increased demands for higher efficiency and environmentally friendly diesel engines have led to a continuous search for new coating processing routes and new ceramic materials that can provide the required properties when applied on engine components such as pistons and exhaust manifolds. Although successful in gas turbine applications, thermal barrier coatings (TBCs) produced by suspension plasma spraying (SPS) processes have not been employed so far in the automotive industry. This work aims to achieve a better understanding of the role of thermal conductivity and thermal effusivity on the durability of SPS TBCs applied to pistons of diesel engines. Three different coating architectures were considered for this study. The first architecture was yttria-stabilized zirconia (YSZ) lamellar top coat deposited by APS (Atmospheric Plasma Spray) and used as a reference sample in this study. The second architecture was a columnar SPS top coat of either YSZ or gadolinium zirconate (GZO) while the third architecture was an SPS columnar top coat, “sealed” with a dense sealing layer deposited on the top coat. Two types of sealing layers were used, a metallic (M) or a ceramic thermal spray layer (C). Laser Flash Analysis (LFA) was used to determine the thermal conductivity and thermal effusivity of the coatings. Two different thermal cyclic tests were used to test the TBCs behavior under cyclic thermal loads. Microstructure analysis before and after the thermal cyclic tests were performed using SEM in different microstructures and materials. The thermal cyclic test results were correlated with coatings microstructure and thermophysical properties. It was observed that the columnar coatings produced by SPS had an enhanced service life in the thermal cyclic tests as compared to the APS coatings.
Place, publisher, year, edition, pages
Elsevier, 2020. Vol. 396, article id 125950
Keywords [en]
Diesel engine, Gadolinium zirconate, Sealing coating, Suspension plasma spray, Yttria stabilized zirconia, Architecture, Automotive industry, Cyclic loads, Diesel engines, Exhaust manifolds, Gas industry, Microstructure, Pistons, Plasma jets, Plasma spraying, Testing, Thermal conductivity, Yttrium oxide, Zirconia, Atmospheric plasma spray, Diesel engine applications, Gas turbine applications, Microstructure analysis, Suspension plasma spraying, Thermal barrier coating (TBCs), Yttria-stabilized zirconias (YSZ), Thermal barrier coatings
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:hj:diva-50099DOI: 10.1016/j.surfcoat.2020.125950ISI: 000540175000022Scopus ID: 2-s2.0-85085597713Local ID: HOA JTH 2020;JTHMaterialISOAI: oai:DiVA.org:hj-50099DiVA, id: diva2:1454563
Funder
Swedish Energy Agency2020-07-172020-07-172020-08-12Bibliographically approved