Plasma Spraying of Functionally Graded ZrO2/NiCoCrAlY Coating System Using Composite Powders

K.A. KhorY.W. Gu

Abstract

Pre-alloyed and plasma spheroidized composite powders were used as the feed-stock in the plasma spraying of functionally graded ZrO2/NiCoCrAlY coatings. The ball milling parameters of the composite powders and the plasma spraying parameters for preparing FGM coatings were optimized in order to obtain the best performance for the thermal barrier coatings. Microstructure, physical, mechanical and thermal properties of ZrO2/NiCoCrAlY FGM coatings were investigated and compared with those of traditional duplex coatings. Results showed that the advantages of using prealloyed composite powders in plasma spraying were to ensure chemical homogeneity and promote uniform density along the graded layers. Microstructure observation showed the gradient distribution of ZrO2 and NiCoCrAlY phases in the coating and no clear interface was found between two adjacent different layers. Oxidation of elements in Ni alloy occurred during plasma spray and the so-formed Al2O3 and Cr2O3 combined with ZrO2 in a wide range of proportions. The bond strength of FGM coatings was about twice than that of the duplex coatings. Results also indicate that the thermal cycling resistance of FGM coating was much better than that of the duplex coating.

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.

© 2021 Meta ULC. All rights reserved