International Refereed Journal of Engineering and Science (IRJES) ISSN (Online) 2319-183X, (Print) 2319-1821 Volume 6, Issue 7 (July 2017), PP.59-65 www.irjes.com 59 | Page Annealing Response of Aluminum Alloy AA6014 Processed By Severe Plastic Deformation * Sanjeev Sharma 1 , M.Sheik Hassan 2 , Brejesh Kumar 3 1 Department of Mechanical Engineering Amity University Gurgaon Haryana, India, 2 Department of Mechanical Engineering Amity University Gurgaon Haryana, India, 3 Center of Nano Technology Amity University Gurgaon Haryana, India, Corresponding author: *Sanjeev Sharma Abstract: In this paper the study of micro structural stability during annealing with respect to time of conventionally grains (CG) and ultrafine-grained (UFG) of Aluminum AA6014 i s carried out. It has been observed that, the effect of the second phase magnesium-silicon particles in the CG and UFG AA6014 samples leads to a rapid hardness which increases from 40HV10 to 70HV10 within 7 days. Artificial aging shows that the material hardness even increased after 20 hours of annealing at 180°C. In total 30 hours of annealing, the hardness arrives at its maximum and then reduces due to the formation of Mg2Si precipitates, which rise in size and change their coherency. The precipitates cannot efficiently pin the dislocations and act as barriers to the dislocation motion which indicate an overall decrease in the hardness. It also has been found that the ultrafine- grained AA6014 alloy loses its thermal stability at approximately 200°C and recrystallized at 300°C. Thermal stability is strongly dependent on the material purity, second phase particles and/or oxide particles which may break up during rolling and lead to some dispersion strengthening. Keywords: Annealing, Ultra-Fine Grained (UFG), Nano- Structured Material, Severe Plastic Deformation, Accumulative I. INTRODUCTION Severe Plastic Deformation (SPD) techniques [1] such as Equal Channel Angular Pressing (ECAP) [2], High Pressure Torsion (HTP) [3], Cyclic Extrusion Compression (CEC) [4], Repetitive Corrugation and Straightening of sheet metals [5] Continuous Confined Strip Shearing and Mechanical Milling process [6] are have s o m e drawbacks. Firstly, the above pointed out processes are found to be improper to produce bulk materials. Secondly, they required forming with dies, which are quite expensive and also required very high forces. As compared to the above processes, the ARB has no such inadequacies. In order to produce ultrafine grained and/or nano-structured bulk aluminum sheets, the ARB process was at first suggested by Saito et al. [7] then it was modified successfully by Tsuji et al. [8] by producing UFG bulk sheet of interstitial free (IF) steel. The four fundamental controlling factors of the ARB process were annealed temperature, inlet temperature, rolling speed and the percentage of reduction. Among the above four factors, annealed temperature was found to be the most important factor influencing accumulative roll bonding. Saito et al. [9] have carried out the same research with AA5083, IF steel and AA1100. Table i. Chemical Composition Aluminium Alloys Aa6014 % By Weight From the material selection point of view Aluminium alloy AA6014 derives its strength primarily from the precipitation strengthening mechanism of the second phase particles Mg2Si. Another advantage of this allow is hat it does not build any strain marks upon sheet metal forming and it is for this reason usually used for the outer body automobile panels. The chemical composition aluminium alloys AA6014 % by weight can be seen in table 1 [10]. II. EXPERIMENTAL PROCEDURES This section addressed the influence of annealing temperature and time on the micro structural evolution, precipitation kinetics, mechanical properties and thermal stability. Therefore the experimental procedure is divided into three major areas: 1) The influence of precipitates in CG aluminium alloy AA6014: