The effect of grain size on the high-temperature fatigue properties of an Mg–0·8% Al alloy has been studied. A reduction in rupture life occurred when the grain size exceeded the specimen thickness. It is shown that this effect is related to an increase in the initial plastic strain amplitude, caused by an increase in the rate of grain-boundary sliding. It is also established that this deformation mode controls cavity growth and that failure occurs at a critical mean value of the sliding displacement, independent of applied stress and structure.
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References
1.
SkeltonR. P., Phil. Mag., 1966, 14, 563.
2.
WilliamsH. D. and CortiC. W., Metal Sci. J., 1968, 2, 28.
3.
EvansH. E., ibid., 1969, 3, 33.
4.
SkeltonR. P., C.E.G.B. Rep. (RD/B/N.773), 1967.
5.
KösterW., Z. Metallkunde, 1948, 39, 1.
6.
GifkinsR. C., J. Australian Inst. Metals, 1963, 8, 148.
7.
BellR. L. and LangdonT. G., J. Mat. Sci., 1967, 2, 313.
8.
HaddrellV. J., J. Inst. Metals, 1963 –64, 92, 121.
