Effect of heat treatment on some mechanical properties of 7075 aluminium alloy

Materials Research

Adeyemi Dayo Isadare²  Bolaji Aremo¹  Mosobalaje Oyebamiji Adeoye¹  Oluyemi John Olawale¹  Moshood Dehinde Shittu¹ 

[1] ,Prototype Engineering Development Institute Ilesa,Nigeria

关键词: 7075 aluminium;    microsegregation;    precipitation hardening;    annealing;    magnesium alloy;    strength;   

DOI  :  10.1590/S1516-14392012005000167

来源: SciELO

【 摘 要 】

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 during rapid cooling. It was also found out that age hardening and annealing heat treatment operation eliminated these microsegregations and improve mechanical properties of 7075 Al alloy. It is concluded that microsegregation can be eliminated by rapid solidification and appropriate heat treatment process.

【 授权许可】

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