Premium
CYCLIC FATIGUE OF Al 2 O 3 AND Al 2 O 3 ‐Al 2 TiO 5 COMPOSITES IN DIRECT PUSH‐PULL
Author(s) -
Bartolomé J. F.,
Requena J.,
Moya J. S.,
Li M.,
Guiu F.
Publication year - 1997
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.1997.tb00308.x
Subject(s) - materials science , aluminium , eutectic system , composite material , titanate , ultimate tensile strength , grain size , sintering , aluminium oxides , microstructure , ceramic , biochemistry , chemistry , catalysis
Abstract— A reaction sintering route is developed to produce, “in situ”, composites of alumina‐aluminium titanate using alumina and titania as starting powders. Aluminium titanate, can be formed by a solid state reaction between Al 2 O 3 and TiO 2 at temperatures above the eutectoid temperature of 1280°C. These composites have different grain sizes of alumina matrix and a different quantity and distribution of aluminium titanate according to the heating cycle used. In the present work direct push‐pull tests under cyclic loads have been carried out with both monolithic alumina and alumina‐aluminium titanate composites. It has been found that all the samples show a decrease in tensile strength with the number of applied cycles of loading when plotted in graphical form but the slopes of these graphs for both Al 2 O 3 ‐Al 2 TiO 5 composites are lower than for the alumina specimens. The role of aluminium titanate and the alumina matrix grain size in fatigue crack growth resistance has been studied during push‐pull tests, where failure occurs by catastrophic propagation of small surface cracks after a very short regime of subcritical crack growth. These results have been compared with measurements of slow stable fatigue crack growth rates in Al 2 O3‐Al 2 TiO 5 composites carried out elsewhere with pre‐notched specimens of the compact tension type. These latter tests provide information about the behaviour of significantly long cracks, i.e. cracks that are several millimetres long.