New evidence on the nature of the metastable S double prime -phase on Al-Cu-Mg alloys

• Published in: Materials chemistry and physics Vol. 130; no. 1-2; pp. 431 - 436
• Main Authors: Novelo-Peralta, O, Figueroa, IA, Lara-Rodriguez, G, Gonzalez, G
• Format: Journal Article
• Language: English
• Published: 17.10.2011
• Subjects: Alloys; Aluminum base alloys; Fourier transforms; High resolution electron microscopy; Orientation; Precipitates; Precipitation; Simulation
• ISSN: 0254-0584
• DOI: 10.1016/j.matchemphys.2011.07.004

Results obtained from high resolution electron microscopy (HRTEM), the resultant fast Fourier transform (FFT) and the simulated electron diffraction patterns (SEDP) presented in this paper provide a better understanding that suggests that there is no S double prime -phase and that the effects attributed to S double prime are explained by consideration of the various variants of the equilibrium S phase on Al-Cu-Mg based alloys (based only on HRTEM analysis). From the 12 orientation variants, only 3 orientations between the matrix and S-phase precipitates were taking into consideration in this study. It was found that the metastable S double prime -phase could be explained as an orientation variant of the equilibrium S-phase (Al2CuMg). It is worth mentioning that the third variant has not been reported in the literature using HTREM, therefore, the incorporation of this variant in the analysis provides an alternative explanation for the experimental evidence previously used as support for the S double prime -phase.