Effect of Mg Content on the Precipitation in Al-Mg-Ge Alloys

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Rod-shaped precipitates in Al -1.1 mass% Mg2Ge (balanced) and Al -1.0 mass% Mg2Ge – 0.5 mass% Mg (excess Mg) alloys aged at 523 K were observed by high-resolution transmission electron microscope (HRTEM) to understand their crystal lattices and chemical compositions. Rod-shaped precipitates were parallel to <100> directions of the matrix. There were 2 groups for rod-shaped precipitates in the base alloy, namely, small cross sections about 10 nm and large ones over 20nm in diameter. Small precipitates showed a hexagonal network of bright dots in their HRTEM images, and its crystal lattice was estimated as a hexagonal having a= 0.72 and c= 0.405 nm based on analysis of HRTEM images and selected area electron diffraction (SAED) patterns. This lattice parameter was slight larger than that of the β’-phase in Al-Mg-Si alloy.

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Periodical:

Materials Science Forum (Volumes 561-565)

Main Theme:

Edited by:

Young Won Chang, Nack J. Kim and Chong Soo Lee

Pages:

2049-2052

Citation:

K. Matsuda et al., "Effect of Mg Content on the Precipitation in Al-Mg-Ge Alloys", Materials Science Forum, Vols. 561-565, pp. 2049-2052, 2007

Online since:

October 2007

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$38.00

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