Mechanical Behavior of AL6061-Pumice Functionally Graded Composite Materials

Kösedağ E., Topuz M., Gökaslan M. Y.

International Pumice and Perlite Symposium, Bitlis, Turkey, 4 - 06 November 2021, pp.27

  • Publication Type: Conference Paper / Summary Text
  • City: Bitlis
  • Country: Turkey
  • Page Numbers: pp.27
  • Van Yüzüncü Yıl University Affiliated: Yes


In thermal barrier applications, the surface exposed to high heat is usually made of ceramic and the other surface

is made of metal. The incompatibility in the thermal expansion coefficient between two materials causes cracks

on the surfaces where metal and ceramics meet, thus decreases in mechanical properties. For this reason,

functionally graded composite material (FGCM) approach has been put forward in order to make the transition

between metal and ceramic more harmonious. In this study, pumice was used as a reinforcement material in the

metal matrix composites (MMCs). Pumice is suitable for use in MMCs because of its very low density, high

hardness and high porosity, especially for thermal insulation applications. 0, 10, 20% pumice-Al6061 MMC and

a FGCM designed as three layers were produced with powder metallurgy method. Vickers hardness and

compression tests were carried out to determine the mechanical properties of MMCs and FGCM. According to the

results, it was understood that the 20% reinforced MMC was 28.1% and 242.7% harder than the 10% reinforced

and non-reinforced, respectively. The 20% reinforced MMC showed 564.5%, 26.8%, 396.4% higher yield strength

than unreinforced, 10% reinforced and FGCM, respectively. FGCM exhibited weaker yield strength compared to

10% and 20% reinforced, and higher yield strength compared to unreinforced Al6061. Finally, it was determined

that the ductility of the material decreased with the increase in the reinforcement ratio. However, it is also

noteworthy that the ductility of FGCM is higher than 10% and 20% reinforced composite.

Keywords: Al6061, Compression test, FGCM, Pumice, Vickers hardness