Retrogression and re-ageing of 7075 aluminium alloy: microstructural characterization

• Type: Article in International Scientific Journal
• Date: 1999

Authors

Viana, F (Author) FEUP; Pinto, AMP (Author) Other; Santos, HMC (Author) Other; Lopes, AB (Author) Other

Journal

Title: Journal of Materials Processing Technology

Vol. 93

Pages: 54-59

ISSN: 0924-0136

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 115 Citations

ISI Web of Science

Scopus - 155 Citations

COMPENDEX

Scientific classification

FOS: Engineering and technology > Civil engineering

Other information

Authenticus ID: P-001-3KE

DOI: 10.1016/s0924-0136(99)00219-8

Abstract (EN): Industrial Summary: The 7075 aluminium alloy presents a low stress corrosion cracking strength when aged to achieve maximum mechanical strength, T6 temper; high stress corrosion cracking strength is attained with overageing, T7 temper; but with loss of mechanical strength. Retrogression and re-ageing treatments improves the stress corrosion behaviour of the alloy whilst maintaining the mechanical resistance of the T6 temper. The microstructures produced by the retrogression and re-ageing treatments were characterized in this study by transmission electron microscopy, electron diffraction and differential scanning calorimetry The precipitation is extremely fine and distributed homogeneously inside the grains, being slightly denser and more stable than that resulting from the T6 temper; whilst the grain boundary precipitation is quite different from that resulting from T6 treatment, the particles being coarser, and much closer to the precipitation resulting from T7 temper. The retrogression temperature is the main property controlling factor; a higher retrogression temperature, increasing the dissolution degree, promotes the formation of more stable precipitates on re-ageing.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6