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The effect of solution heat‐treatment time on the fatigue properties of an Al‐Si‐Mg casting alloy
Author(s) -
DAVIDSON C. J.,
GRIFFITHS J. R.,
MACHIN A. S.
Publication year - 2002
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 - 10.1046/j.8756-758x.2001.00490.x
Subject(s) - casting , materials science , alloy , fatigue limit , metallurgy , tension (geology) , composite material , ultimate tensile strength
Experiments have been carried out to investigate whether reducing the solution heat‐treatment time of Al‐7Si‐0.6Mg castings from the currently recommended values adversely affects their fatigue properties. Fatigue endurance tests have been carried out in zero‐tension ( R =0) and measurements made of the casting defects that initiated the fatigue cracks. The work has been limited to stresses that produce a fatigue life of ~10 5 cycles and to two solution–treatment times (8 and 4 h). Two statistical techniques have been applied to the fatigue life data and no effect of solution heat‐treatment time was detected at a confidence level of better than 95%. Similarly, no effect of cyclic test frequency could be detected for tests carried out at 1 and 60 Hz. The conclusions are confirmed by an analysis of the relation between fatigue life and the size of the casting defects that initiated fatigue failure. The scatter in fatigue lives is related to the scatter in the sizes of casting defects in the specimens. It is clear that there is a potential for considerable savings in heat‐treatment costs for castings of the size and shape chosen for the study.