Next Article in Journal / Special Issue
Study on the Growth of Holes in Cold Spraying via Numerical Simulation and Experimental Methods
Previous Article in Journal
Study of a Particle Based Films Cure Process by High-Frequency Eddy Current Spectroscopy
Article Menu
Issue 1 (January) cover image

Export Article

Open AccessArticle
Coatings 2017, 7(1), 4; doi:10.3390/coatings7010004

Influence of Isothermal Heat Treatment on Porosity and Crystallite Size in Axial Suspension Plasma Sprayed Thermal Barrier Coatings for Gas Turbine Applications

Department of Engineering Science, University West, Trollhättan 46186, Sweden
*
Author to whom correspondence should be addressed.
Academic Editor: Yasutaka Ando
Received: 15 November 2016 / Revised: 25 December 2016 / Accepted: 26 December 2016 / Published: 28 December 2016
(This article belongs to the Special Issue Thermal Spray Technology)
View Full-Text   |   Download PDF [6325 KB, uploaded 28 December 2016]   |  

Abstract

Axial suspension plasma spraying (ASPS) is an advanced thermal spraying technique, which enables the creation of specific microstructures in thermal barrier coatings (TBCs) used for gas turbine applications. However, the widely varying dimensional scale of pores, ranging from a few nanometers to a few tenths of micrometers, makes it difficult to experimentally measure and analyze porosity in SPS coatings and correlate it with thermal conductivity or other functional characteristics of the TBCs. In this work, an image analysis technique carried out at two distinct magnifications, i.e., low (500×) and high (10,000×), was adopted to analyze the wide range of porosity. Isothermal heat treatment of five different coatings was performed at 1150 °C for 200 h under a controlled atmosphere. Significant microstructural changes, such as inter-columnar spacing widening or coalescence of pores (pore coarsening), closure or densification of pores (sintering) and crystallite size growth, were noticed in all the coatings. The noted changes in thermal conductivity of the coatings following isothermal heat treatment are attributable to sintering, crystallite size growth and pore coarsening. View Full-Text
Keywords: axial suspension plasma spraying; thermal barrier coatings; sintering; pore coarsening; nano-sized pores; crystallite size growth; thermal conductivity axial suspension plasma spraying; thermal barrier coatings; sintering; pore coarsening; nano-sized pores; crystallite size growth; thermal conductivity
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Ganvir, A.; Markocsan, N.; Joshi, S. Influence of Isothermal Heat Treatment on Porosity and Crystallite Size in Axial Suspension Plasma Sprayed Thermal Barrier Coatings for Gas Turbine Applications. Coatings 2017, 7, 4.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Coatings EISSN 2079-6412 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top