Influence of Vacancy Formation and Mg Migration on Cracking in Spot Welding AA5754 Alloys

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Al alloys with Mg as the major alloying element constitute a group of non-heat treatable alloys with medium strength, high ductility, excellent corrosion resistance and weldability. However, the segregation of Mg may adversely affect the performance of these materials if they are exposed to rapid heating and cooling environments such as resistance spot welding. The formation and migration of vacancy is an important factor affecting Mg segregation. In this paper, the amount and distribution of Mg were measured by electron probe microanalysis and the vacancy formation energy in AA5754 alloys was measured by positron annihilation lifetime spectroscopy. The results indicated that the segregation of Mg at cracks, occurring under suitable temperature and stress conditions, is related to the formation and migration of vacancies, and may promote crack initiation and propagation.

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Periodical:

Materials Science Forum (Volumes 539-543)

Main Theme:

Edited by:

T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran

Pages:

433-437

Citation:

X. W. Wang et al., "Influence of Vacancy Formation and Mg Migration on Cracking in Spot Welding AA5754 Alloys", Materials Science Forum, Vols. 539-543, pp. 433-437, 2007

Online since:

March 2007

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$38.00

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