On the cyclic behavior of cast and extruded aluminum alloys. Part A: Fatigue crack propagation

✍ Scribed by R.J. Stofanak; R.W. Hertzberg; G. Millers; R. Jaccard; K. Donald

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 1012 KB
• Volume: 17
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(83)90113-3

✦ Synopsis

The fatigue crack propagation (FCP) response of a cast and extruded aluminum alloy was examined as a function of mean stress and specimen orientation. The extruded alloy was tested in both the longitudinal and transverse orientation and no difference in FCP response was noted. FCP tests were conducted at R ratios of 0.1,0.5,0.65 and 0.8. In the threshold regime, it was seen that as R ratio increased, &n decreased. In addition, AK,, values determined for the cast alloy were superior to those determined for the extruded alloy at all R ratios examined. The threshold regime was also shown to be KYAX rather than .tjK dependent. At intermediate AK levels, a mean stress effect was seen for both alloys at R ratios less than OS. Crack closure was monitored during testing so that AKErr values could be determined. bKFFF was seen to explain mean stress effects at intermediate AK levels.