论文信息 - Improvement of Fatigue Properties by Means of Continuous Cyclic Bending and Annealing in an Al-Mg-Mn Alloy Sheet

Improvement of Fatigue Properties by Means of Continuous Cyclic Bending and Annealing in an Al-Mg-Mn Alloy Sheet

The fatigue properties in the Al-Mg-Mn alloy sheet subjected by the continuous cyclic bending (CCB) and annealing have beeninvestigated.BytheCCBandsubsequentannealing,thegradientmicrostructurewithcoarse-grainedsurfacelayersandﬁne-grainedcentrallayeris produced in the sheet.Thefatiguelife of theCCBentandannealedsheetis 2–4times longerthan that ofthe as-receivedone.Theexistence ofthe coarse-grained surface layers makes the crack propagation rate lower by a factor of 1/2 to 1/3. The fatigue crack growth in the sheetconsisting of such diﬀerent microstructure layers is characterized by the fractography. Further, factors improving the fatigue properties arediscussed.(Received March 25, 2004; Accepted April 23, 2004)Keywords: fatigue, aluminium-magnesium-manganese alloy, continuous cyclic bending, crack propagation, grain size

Hideo Watanabe | Y. Takayama | J. Sasaki | H. Kato

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