Paper Title:
Mechanical Properties of Alumina Matrix Composites due to a Combination of Sr- and Ca-Hexaluminates
  Abstract

Alumina matrix composites have been successfully used in a wide range of applications for decades. Even alumina itself provides several desirable properties e.g. strength, chemical and thermal stability together with hardness, its toughness is still to be concerned. An addition of some intermediate phases such as alkali earth hexaluminates can enhance fracture toughness according to their unique morphology. This work investigated a variation in mechanical properties of alumina as a presence of two types of dispersed phases: strontium hexaluminate and calcium hexaluminate. The preformed hexaluminate compounds were prepared from a powder mixture of the alkali earth carbonates and alumina. The preformed hexaluminates were then added into alumina, followed by pressureless sintered at 1600 oC for 2 hours in air. A change in mechanical properties of alumina according to types and amount of additives as well as the ratio of calcium hexaluminate to strontium hexaluminate compounds on was studied. The composites with the relative density of at least 93%TD were achieved. Both hexaluminates resulted in a significant increase in fracture toughness relative to the monolithic alumina while they slightly affected on hardness and strength. When the ratio of calcium hexaluminate to strontium hexaluminate in alumina matrix was considered, a rise in fracture toughness strongly depended on the fraction of calcium hexaluinate. The calcium hexaluminate tended to be more efficient additive in order to strengthen alumina than that of the strontium ones

  Info
Periodical
Edited by
Takashi Goto, Yi-Bing Cheng and Takashi Akatsu
Pages
102-105
DOI
10.4028/www.scientific.net/KEM.484.102
Citation
W. Buggakupta, "Mechanical Properties of Alumina Matrix Composites due to a Combination of Sr- and Ca-Hexaluminates", Key Engineering Materials, Vol. 484, pp. 102-105, 2011
Online since
July 2011
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Eniko Volceanov, Ştefania Motoc, Adrian Volceanov, Rodica M. Neagu, Cristian Coman
2283
Authors: Doreya M. Ibrahim, Amani A. Mostafa, T. Khalil, J. Bossert
821
Authors: Oleg Vasylkiv, Yoshio Sakka, Valeriy Skorokhod
Abstract:The 0.75 to 3 mol% Y2O3-stabilized tetragonal ZrO2 and Al2O3/Y-TZP nano-composite ceramics with 0.2 to 0.7 wt% of alumina were produced by a...
615
Authors: Isabel M. Martins, Claudino Xavier, Maria Helena Mendonça, Manuela Oliveira
Abstract:Previous studies had shown that a promising material could be obtained by mixing aluminium-rich sludge with slate powder (with Al2O3:SiO2...
1695
Authors: Bao Yu Du, Bo Zhao, Tie Lin Duan
Chapter 6: Mechanical Design and Manufacture Technology (2)
Abstract:Physical and mechanical properties as well as microstructure of zirconia toughened alumina ceramics with different zirconia content were...
485