TEM and DSC Analysis of LT-3 Aluminum Alloy Vacuum Brazing

Abstract:

Crystallization of aluminum alloy directly affects the brazing beam quality. The transmission electron microscopy (TEM) was used to measure lattice parameter of aluminum in the brazing beam. And the differential scanning calorimeter (DSC) was used to measure endothermic and exothermic reaction in the vacuum brazing process. The experiment results indicate that the latent heat of crystallization in the crystallization is –370.7J/g, the critical work of nucleation is 3.82×10－17J, the critical radius of nucleation is 8.69×10－10m, the volume of critical crystal nucleus is 2.75×10－27m3 and the per unit cell in critical crystal nucleus is 43, the number of atoms is 172, in the actual crystallization the number is less than 172.

• Periodical: Advanced Materials Research (Volumes 538-541)
• Pages: 1502-1506
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.538-541.1502
• Online since: June 2012
• Authors: Jing Nian Xu, Xiu Li Cao, Tao Feng, Yong Ang Zhang
• Keywords: Crystallization, LT-3 Aluminum Alloy, Vacuum Brazing

References

[1] William Hoke II, Calvin Amenheuser. Techniques for aluminum brazing in vacuume furnaces. Welding Journal. 72(1993): 65~67

[2] J.R. Terrill, C.N. Cochran, J.J. Stokes, W.E. Haupin. Understanding the mechanisms of aluminum brazing. Welding Journal. 50(1971): 833s~839s

[3] Zhang Yuhua, Shi Chuncheng. Study on vacuum brazing of aluminum alloy. Transactions of the China Welding Institution (in Chinese). 4(1983): 55~71

[4] Pan Xuchun, DusanP.Sekulic. Microstructural characteristics of AA4343/AA3003 Al-alloy sheet brazed joints. The Chinese Journal of Nonferrous Metals (in Chinese). 12(2002): 481~485

[5] Qiu Xiaoming, Yin Shiqiang, Sun Daqian, Chen Zhiming. Thermodynamical analysis on Al eutectic reaction brazing. The Chinese Journal of Nonferrous Metals (in Chinese). 11(2001): 1017~1020

[6] Gu Xiren. Surface Chemistry. Scientific Publishing Company. (1994)