•  
  •  
 

Journal of Materials Exploration and Findings

Abstract

This paper reports the effects of sample placement during the heat treatment on the microstructural morphology and mechanical properties of 7075 Al alloy such as hardness value and electrical conductivity. The material was in the formed of Al alloy sheets where samples were machined into a square with dimensions of 1.5 x 1.5 inch. The 7075-T0 Al alloy as samples were given heat treatment by precipitation hardening (aging) at temperature 120°C for 24 hours, so it becomes 7075-T6 Al alloy. Samples were subjected to some mechanical tests and the morphology of the resulting microstructures were characterized by optical microscopy. The variable was the placement of samples in the furnace which is based on the differences of the 7075 Al alloy properties, from aging process T0 to T6, in microstructure, hardness value and electrical conductivity even though the tools, materials and treatment given are the same. The study showed that as far as the sample from the furnace door, hardness values were increased while the electrical conductivity decreased and it was proportional to the dispersion of precipitates that occurred.

References

[1] Chee FT and Mohamad RS. Effect of hardness test on precipitation hardening aluminium alloy 6061-T6. Chiang Mai Journal of Science. 2009; 36(3):276-86.

[2] Isadare, A. D., Aremo, B., Adeoye, M. O., Olawale, O. J., & Shittu, M. D. (2012). Effect of heat treatment on some mechanical properties of 7075 aluminium alloy. Materials Research, 16(1), 190–194.

[3] J. T. Staley, Proc. 3rd Int. Conf. on Al. Alloys (eds. L. Arnberg, O. Lohne, E. Nes, N. Ryum), p.107, Norwegian Institute of Technology, SINTEF, Trondheim, Norway (1992).

[4] Machler R, Uggowitzer PJ, Solenthaler C, Pedrazzoli RM and Spiedel MO. Structure, mechanical properties, and stress corrosion behaviour of high strength spray deposited 7000 series aluminium alloy. Materials Science Technology. 1991; 7:447-51.

[5] Du ZW, Sun ZM, Shao BL, Zhou TT and Chen CQ. Quantitative evaluation of precipitates in an Al-Zn-Mg-Cu alloy after isothermal aging. Materials Characterization. 2006; 56:121-8.

[6] Boeing Aircraft Company (BAC) Standard 5602, Heat Treatment of Aluminum Alloys, Boeing Process Specification. Revised 28-AUG-2001.

[7] Salamci E. Ageing behaviour of spray cast Al-Zn-Mg-Cu alloys. Turk Journal of Engineering and Environmental Science. 2001; 25(6):681-686.

[8] Fan X, Jiang D, Meng Q, Zhang B and Wang T. Evolution of eutectic structures in Al-Zn-Mg- Cu alloys during heat treatment. Transactions of Nonferrous Metal Society of China. 2006; 16:577-81. http://dx.doi.org/10.1016/ S1003-6326(06)60101-5

[9] Ringer, S. P., Sakurai, T., & Polmear, I. J. (1997). Origins of hardening in aged Al-Cu-Mg-(Ag) alloys. Acta Materialia, 45(9), 3731–3744.

[10] Boeing Aircraft Company (BAC) Standard 5946, Temper Inspection of Aluminum Alloys, Boeing Process Specification. Revised 09-JUL-2001.

[11] Feng, Z., Yang, Y., Huang, B., Han, M., Luo, X., & Ru, J. (2010). Precipitation process along dislocations in Al–Cu–Mg alloy during artificial aging. Materials Science and Engineering: A, 528(2), 706–714.

[12] Shih, H.-C., Ho, N.-J., & Huang, J. C. (1996). Precipitation behaviors in Al-Cu-Mg and 2024 aluminum alloys. Metallurgical and Materials Transactions A, 27(9), 2479–2494.

[13] Callister WD. Materials science and engineering: an introduction. 4th ed. New York: John Willey and Son Inc.; 1997.

[14] Pankade, S. B., Khedekar, D. S., & Gogte, C. L. (2018). The influence of heat treatments on electrical electrical conductivity and corrosion performance of AA 7075-T6 aluminium alloy. Procedia Manufacturing, 20, 53–58.

[15] Salazar-Guapuriche, M. A., Zhao, Y. Y., Pitman, A., & Greene, A. (2006). Correlation of Strength with Hardness and Electrical Conductivity for Aluminium Alloy 7010. Materials Science Forum, 519-521, 853–858.

[16] Chen, Gang & Chen, Qiang & Wang, Bo & Du, Zhi-ming. (2015). Microstructure Evolution and Tensile Mechanical Properties of Thixoformed High Performance Al-Zn-Mg-Cu Alloy. Metals and Materials International. 21. 897-906. 10.1007/s12540-015-5139-6.

[17] Goloborodko, Alexandre & Ito, Tsutomu & Yun, Xiaoyong & Motohashi, Y. & Itoh, Goroh. (2004). Friction Stir Welding of a Commercial 7075-T6 Aluminum Alloy: Grain Refinement, Thermal Stability and Tensile Properties. MATERIALS TRANSACTIONS. 45. 2503-2508. 10.2320/matertrans.45.2503.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.