Suppression of Fatigue Crack Propagation of Duralumin by Cavitation Peening

Abstract

It was demonstrated in the present paper that cavitation peening which is one of the mechanical surface modification technique can suppress fatigue crack propagation in duralumin. The impacts produced when cavitation bubble collapses can be utilised for the mechanical surface modification technique in the same way as laser peening and shot peening, which is called “cavitation peening”. Cavitation peening employing a cavitating jet in water was used to treat the specimen made of duralumin Japanese Industrial Standards JIS A2017-T3. After introducing a notch, fatigue test was conducted by a load-controlled plate bending fatigue tester, which has been originally developed. The fatigue crack propagation behavior was evaluated and the relationship between the fatigue crack propagation rate versus stress intensity factor range was obtained. From the results, the fatigue crack propagation rate was drastically reduced by cavitation peening and the fatigue life of duralumin plate was extended 4.2 times by cavitation peening. In addition, the fatigue crack propagation can be suppressed by 88% in the stable crack propagation stage by cavitation peening.

Keywords

• fatigue cracks
• aluminium alloys
• cavitation
• shot peening
• standards
• stress analysis
• fatigue testing
• plates (structures)
• fatigue crack propagation suppression
• cavitation peening
• mechanical surface modification technique
• cavitation bubble collapses
• laser peening
• shot peening
• cavitating jet
• duralumin Japanese Industrial Standards
• JIS A2017-T3
• notch test
• load-controlled plate bending fatigue tester
• fatigue crack propagation behavior
• fatigue crack propagation rate
• stress intensity factor range
• fatigue life