Study On Impression Creep Behavior Of Aluminium Conductor

The creep resistant of aluminum conductor is very important, related to the transmissionsecurity. In this paper,1A60,1R50and6101aluminum conductor were choosen as theresearch object, and simulation the conductor joint as working condition by impression creep.Under the condition of90-230℃and80-140MPa, the impression creep property of theconductor was investigated by a special apparatus, constructing constitutive equations of thesteady-state impression creep and the impression creep mechanism of the conductor under theexperiment condition can be concluded. The microstructural evolution before and after creepare analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). Theresults are as follows:1)Under the condition of temperature and stress in this study, the stress exponents of theannealed and work hardening1A60aluminium conductor are respectively4.49and4.22, thecreep activation energy are respectively20.0KJ/mol and41.8KJ/mol; the stress exponents ofthe annealed and work hardening1R50aluminium conductor are respectively4.17and3.11,the creep activation energy are respectively33.6KJ/mol and37.4KJ/mol; the stress exponentsof the annealed and work hardening6101aluminium conductor are respectively4.54and3.48,the creep activation energy are respectively76.0KJ/mol and80.7KJ/mol.2)Three kinds of aluminum conductors creep performance study shows that: the creepresistant properties of6101aluminum conductor is the best,the1R50is worse and the1A60isworst; the creep resistant properties of the work-hardening aluminium conductor is better thanthe annealed aluminium conductor.3)There are no new phases was find out after creep experiment in annealed1A60,1R50and6101aluminium conductor. Al12Fe3Si phase were found out exist in the1A60aluminiumconductor matrix, and Al12Fe3Si phase force broken will split matrix, reduced the creepresistance of the1A60aluminium conductor; In1R50aluminium conductor, trace RE andimpurity element in the matrix which formed new globular compound phase(AlFeSiRE), itchanged the impurity phase morphology and reduced the degree of impurity phase splitmatrix, and thus improve the creep resistance of1R50aluminium conductor; The creepresistance of6101aluminium conductor is the best of the three, because of the strengthendingphase Mg2Si improve the strength and creep resistance of the conductor.4) Under the condition of temperature and stress in this study t, the impression creepmechanism of annealed1A60aluminum conductor is dislocation climbing by grain boundaryslipping and the impression creep mechanism of work hardening1A60aluminum conductoris dislocation climbing by aluminum self diffusion; the impression creep mechanism ofannealed1R50aluminum conductor is dislocation climbing by aluminum self diffusion andthe impression creep mechanism of work hardening1R50aluminum conductor is dislocationslipping by aluminum self diffusion; the impression creep mechanism of annealed6101aluminum conductor is dislocation climbing by grain boundary diffusion and the impression creep mechanism of work hardening6101aluminum conductor is dislocation slipping bygrain boundary diffusion.