STP520: Temperature Dependence of Fatigue Crack Propagation in an Al-2.6Mg Alloy

    Jeglic, F
    Graduate student, and professors, University of Waterloo, Waterloo, Ont.

    Niessen, P
    Graduate student, and professors, University of Waterloo, Waterloo, Ont.

    Burns, DJ
    Graduate student, and professors, University of Waterloo, Waterloo, Ont.

    Pages: 10    Published: Jan 1973


    Abstract

    Fatigue crack propagation has been studied in an Al-2.6Mg alloy between room temperature and 300 C. It is shown that the fatigue crack propagation rate is controlled by volume diffusion. The activation barrier for volume diffusion (Q0) is lowered by the applied stress intensity range ΔK so that QK) = Q0 - C1 log ΔK. The driving force for the process is inversely proportional to the square of the stress intensity range: AK) = C2 ΔK-2. Fatigue crack propagation rate as a function of temperature and stress intensity range is given by daDN=C2ΔK-2exp-[Q0-C1logΔKRT] A special case of this equation is the well-known Paris equation.

    Keywords:

    fatigue (materials), crack propagation, aluminum alloys, stresses, thermal fatigue, cyclic strain, activation energy


    Paper ID: STP38835S

    Committee/Subcommittee: E08.05

    DOI: 10.1520/STP38835S


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