Skip to main content Accessibility help

Processing-Microstructure-Property Relations in Anisotropic Thermal Sprayed Composites

  • Weiguang Chi (a1), Vasudevan Srinivasan (a2), Atin Sharma (a3), Sanjay Sampath (a4) and Richard Gambino (a5)...


Thermal spray is a significantly advanced but inherently complex deposition process that involves successive impingement of molten droplets on a substrate to form coating with a ¡°brick-wall¡± layered structure. The anisotropic microstructure of coatings is very sensitive to processing conditions and has significant influence on the properties. This study aims to understand the processing-microstructure-thermal property correlation of thermally sprayed coatings. Thermal transport properties of three coating systems forming composites with pores (yttria stabilized zirconia (YSZ) -Air), a second phase (Mo-Mo2C) and a graded material (YSZ-NiCrAlY) are interpreted from the point of view of microstructure and chemical composition. In the case of YSZ-Air composite, results indicate that porosity contribution from 20-35% decreases the thermal conductivity by 50-70% of the bulk value. For the intrinsic composite of Mo and Mo2C, which coexist as stable phases, thermal conductivity increases significantly with 1.75wt% carbon addition since it reduces formation of MoO2 during processing, but decreases with 3.5wt% carbon addition. This is attributed to larger carbide retention in the latter. For the discrete layered and graded composites of YSZ-NiCrAlY, which are made up of varying fractions of these two constituents, thermal conductivity decreases sharply up to 40wt% YSZ and then more gradually with increasing YSZ content. This paper examines these experimental findings by treating the these complex coatings as multiphase composites.



Hide All
1. Morf, E., U.S. Patent 28001 A. D. (1912).
2. Wang, Z., Kulkarni, A., Deshpande, S., Nakamura, T., and Herman, H., Acta Materialia. 51, 53195334 (2003).10.1016/S1359-6454(03)00390-2
3. Chi, W., Sampath, S., and Wang, H., Journal of Thermal Spray Technology. 15, (2006).10.1361/105996306X146730
4. Sampath, S., Jiang, X. Y., Matejicek, J., Prchlik, L., Kulkarni, A., and Vaidya, A., Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing. 364, 216231 (2004).10.1016/j.msea.2003.08.023
5. Kulkarni, A., Wang, Z., Nakamura, T., Sampath, S., Goland, A., Herman, H., Allen, J., Ilavsky, J., Long, G., Frahm, J., and Steinbrech, R. W., Acta Materialia. 51, 24572475 (2003).10.1016/S1359-6454(03)00030-2
6. Smith, L. N., and Lobb, C. J., Physical Review B. 20, 36533658 (1979).10.1103/PhysRevB.20.3653
7. Sampath, S., and Wayne, S. F., Journal of Thermal Spray Technology. 3, 282288 (1994).10.1007/BF02646273
8. Prchlik, L., Sampath, S., Gutleber, J., Bancke, G., and Ruff, A. W., Wear. 249, 11031115 (2001).10.1016/S0043-1648(01)00839-0
9. Padture, N. P., Gell, M., and Jordan, E. H., Science. 296, 280284 (2002).10.1126/science.1068609
10. Sampath, S., Smith, W. C., Jewett, T. J. and Kim, H., Materials Science Forum. 308–311, p 383388 (1999).10.4028/
11. Sampath, S., Herman, H., Shimoda, N., and Saito, T., MRS Bulletin. 20, 2731 (1995).10.1557/S0883769400048880



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed