Journal of Engineering Science and Technology (Dec 2018)
CHARACTERIZATION OF ABRASIVE WEAR PROPERTIES OF PLASMA SPRAYED ALUMINA AND YSZ COATINGS ON ALUMINIUM 6061 SUBSTRATE
Abstract
On the embarked journey of curtailing heat losses and dwindling wear in internal combustion engines and gas turbines, Thermal Barrier Coatings (TBCs) play a prominent role. As TBC increase the efficiency of the engine by reducing heat losses. Review of the literature reveals one of the favoured techniques for the application of TBC is by atmospheric plasma spraying and delving of wear characteristics of TBC by plasma spraying are to be effectuated. To fill this research void, the investigation is carried out with a three-layered TBC on aluminium 6061 base/substrate material. The substrate was first coated with a metallic bond material (Al 25Fe7Cr5Ni) and above that, a cermet bond material (Al2O3 30(Ni20Al)) was applied. The third top layer was a pure ceramic coat, which encompasses the mixture of pure alumina (Al2O3) and Yttria-Stabilized Zirconia (YSZ; ZrO28Y2O3) in equal proportions. The topcoat thickness of pure ceramic was varied (100, 200 and 300 µm) and the coated samples were subjected to various studies (microstructure, XRD analysis, porosity and abrasive wear). Conscientious inquests of results divulge reliance of coefficient of friction and wear on loading conditions, initially wear is by the result of abrasion and once the bond coat was revealed it is by adherence and wear rate decreases with increase in load. Feasibility of Al2O3 and ZrO28Y2O3 as a thermal barrier coating was espied and enhanced wear characteristics emanated.
