Effect of thermal and surface chemical treatment on the cyclic oxidation behavior of 7039 aluminum alloy used in aerospace armor applications Yahya Ali Fageehi a , Rajasekaran Saminathan a,⇑ , Gunasekaran Venugopal b , James Valder c , Hemanth Kumar d , K.S. Ravishankar e a Mechanical Engineering, Jazan University, Jazan 45142, Saudi Arabia b Materials Science, Central University, Thiruvarur 610005, India c Mechanical Engineering, SJEC (VTU), Mangaluru 575028, India d Physics, Bharat Institute of Higher Education and Research, Chennai 600 073, India e Metallurgical and Materials Engineering, N.I.T.K, Surathkal, Karnataka 575025, India article info Article history: Received 28 August 2020 Received in revised form 18 September 2020 Accepted 20 September 2020 Available online xxxx Keywords: Cyclic oxidation test 7039 aluminium alloy Artificial aging Ceramic coating Aerospace armor applications abstract 7039 Aluminum alloy is subjected to artificial aging (T6 treatment) at temperatures namely 80, 100, 120, 140, 160 °C for various time periods up to 100 h. Based on the Brinell Hardness measurements the arti- ficially aged alloys are categorized into three groups namely under aged, peak aged and overaged based. The specimens from the alloy groups are further subjected to cyclic oxidation measurements at temper- atures namely 100, 200 and 300 °C. The cyclic oxidation measurements in atmospheric air, revealed that the pre temperature history of the artificially aged alloy has an influence on the cyclic oxidation behavior of the 7039 Aluminum alloy as the under aged alloy showed greater tendency for cyclic oxidation. A sur- face chemical treatment is employed to coat the alloy by CeO 2 ceramic coating through chemical bath technique. Cyclic oxidation tests, X-RD and SEM analysis of the 7039 Aluminum alloy specimens with and without ceramic coatings are carried out. Interestingly, the ceramic coated 7039 Aluminum alloy showed greater resistance to oxidation when compared to that of artificially aged alloy specimens. Ó 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Second International Conference on Recent Advances in Materials and Manufacturing 2020. 1. Introduction The concept of designing aluminum alloys is attracting the attention of the researchers recently in real time engineering appli- cations due to various types of industrial needs require alloys of different tailor made properties. Depending on the end properties alloying elements like Cu, Si, Mn, Mg, Zn etc., are alloyed with Alu- minum in recent decades to develop variety of aluminum alloys for various engineering applications [1]. The most important factor among all necessary parameters in alloy design is the strength to weight ratio deciding the applicability of the alloy in various indus- trial applications. There is a great potential for the Aluminum based materials in advancing fields like aerospace engineering, nano technology etc., due the combination of superior properties and also the reliability [2]. Among the recently developed alloys the 7xxx series alloys are of ternary nature with alloying elements like Zn, Mg and Si etc. They possess very good mechanical proper- ties and heat treatable to achieve desirable mechanical strength depending on the end applications. Among 7xxx Aluminum alloys, 7039 Aluminum alloy is unique due its high strength and energy absorption capacity and hence it is known as aerospace Armor grade alloy [3–5]. Subjecting the Aluminum alloy to heat treatment in order to improve its strength has a greater influence on its ductility, oxida- tion and corrosion resistance. Eventually there is a need to study the effect of heat treatment processes on the other characteristics of the Aluminum alloys [6,7]. In particular, study on cyclic oxida- tion resistance of the alloys used in engineering applications where thermal fatigue is one of the major cause of failures in the struc- tures during real time utility, is receiving greater attention [8,9]. Understanding the reaction kinetics in thermodynamically assisted oxidation process at high temperatures is very essential in order to further concentrate on the development of techniques to minimize its effect on the mechanical properties of the alloy [10,11]. Many https://doi.org/10.1016/j.matpr.2020.09.547 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Second International Conference on Recent Advances in Materials and Manufacturing 2020. ⇑ Corresponding author. E-mail addresses: rajasekaran.saminathan@gmail.com, rsaminathan@jazanu. edu.sa (R. Saminathan). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: Y. Ali Fageehi, R. Saminathan, G. Venugopal et al., Effect of thermal and surface chemical treatment on the cyclic oxidation behav- ior of 7039 aluminum alloy used in aerospace armor applications, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.09.547