ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The variation of the hardness of a complex Al alloy, of the L70 type, (Al 4% Cu 0.8% Si 0.8% Mg 0.7% Mn 0.5% Fe) with ageing time at 130, 160 and 190° C was measured and correlated with transmission electron microscope observations of preciptate morphology. It was established that the peak hardness, after both 160 and 190° C ageing, was associated with coherentθ′ precipitate particles with a diameter of ∼ 700 Å and the subsequent limited overageing at these temperatures was controlled by the slow growth ofθ′ particles. Measurements ofθ′ particle coarsening at 220° C suggested that the process occurred by Ostwald ripening. In contrast, ageing at 130° C gave a series of hardness—time plateaus, which were ascribed to the sequential precipitation of zones,θ′' andθ′ precipitates.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00737522
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