Deep-cryogenic-treatment-induced phase transformation in the Al-Zn-Mg-Cu alloy

• Published in: International journal of minerals, metallurgy and materials Vol. 22; no. 1; pp. 68 - 77
• Main Authors: Li, Chun-mei, Cheng, Nan-pu, Chen, Zhi-qian, Guo, Ning, Zeng, Su-min
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 2015; Springer Nature B.V; School of Materials Science and Engineering, Central South University, Changsha 410083, China
• Subjects: Al-Zn-Mg-Cu系合金; Alloy systems; Aluminum; ALUMINUM ALLOYS (50 TO 99 AL); Aluminum base alloys; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Copper; Corrosion and Coatings; Cryogenic treatment; DCT; Electron microscopy; First principles; Glass; Guinier Preston zone; High resolution electron microscopy; Magnesium; Materials Science; MATHEMATICAL ANALYSIS; MECHANICAL PROPERTIES; Metallic Materials; Microstructure; MICROSTRUCTURES; Natural Materials; Phase transformations; Phase transitions; Precipitation; PROPERTIES; Surfaces and Interfaces; Thin Films; Tribology; Zinc; 低温处理; 深冷处理; 电子显微镜观察; 相变; 第一性原理计算; 诱导; cryogenic treatment; microstructure; aluminum alloys; phase transformation
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-015-1045-7

An aluminum alloy （Al-Zn-Mg-Cu） subjected to deep cryogenic treatment （DCT） was systematically investigated. The results show that a DCT-induced phase transformation varies the microstructures and affects the mechanical properties of the Al alloy. Both Guinier-Preston （GP） zones and a metastableη′phase were observed by high-resolution transmission electron microscopy. The phenomenon of the second precipitation of the GP zones in samples subjected to DCT after being aged was observed. The viability of this phase transfor-mation was also demonstrated by first-principles calculations.