Effect of Heat Treatment on Some Mechanical （热处理对一些机械的影响）.pdfVIP

Materials Research . 2013; 16(1): 190-194 © 2013 DOI: 10.1590/S1516-14392012005000167 Effect of Heat Treatment on Some Mechanical Properties of 7075 Aluminium Alloy a b c Adeyemi Dayo Isadare , Bolaji Aremo , Mosobalaje Oyebamiji Adeoye , c c Oluyemi John Olawale *, Moshood Dehinde Shittu aPrototype Engineering Development Institute Ilesa, Nigeria b Centre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife, Nigeria cDepartment of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria Received: April 14, 2012; Revised: September 3, 2012 This paper reports the effects of annealing and age hardening heat treatments on the microstructural morphology and mechanical properties of 7075 Al alloy. The material was cast in the form of round cylindrical rods inside green sand mould from where some samples were rapidly cooled by early knockout and others gradually cooled to room temperature. From the samples that were gradually cooled some were annealed while others were age hardened. Both the as-cast in each category and heat treated samples were subjected to some mechanical tests and the morphology of the resulting microstructures were characterised by optical microscopy. From the results obtained there is formation of microsegregations of MgZn2 during gradual solidification which was not present dur