Electrochemical investigation of calcined agrowastes powders on friction stir processing of aluminium-based matrix composites O.M. Ikumapayi a,⇑ , E.T. Akinlabi a , O.O. Abegunde a , O.S.I. Fayomi b a Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park Kingsway Campus, Johannesburg 2006, South Africa b Department of Mechanical Engineering, Covenant University, Ota, P.M.B 1023, Nigeria article info Article history: Received 6 November 2019 Accepted 14 February 2020 Available online xxxx Keywords: Agrowastes inhibitors Aluminium alloy Corrosion resistance Carbonaceous powders Friction stir processing abstract The ultimate goal of this report was to use eco-friendly calcined agro-waste powders such as coconut shell ash (CSA), cow bone ash (CBA) as well as palm kernel shell ash (PKSA) and to analyze the percentage inhibition performance efficiency (percent IPE) on friction stir processed (FSP) of super strength aluminum alloy 7075-T651. The motive behind this study was to establish whether agro-waste powders could serve as a successful alterative to metallic powders for enhancing as well as corrosion resistance in aluminum alloy 7075-T651. The study reported three different carbonaceous agro-waste powders such as PKSA, CBA and CSA in 3.5 percent NaCl as reinforcements and corrosion prevention and confirmed that PKSA as corrosion susceptible performed better than CBA and CSA under the same environmental factors and can be an acceptable substitute for metallic powders as a corrosion protection. The results established that PKSA has the least corrosion rate of 0.4357 mm/year and this was followed by the rein- forcement from CSA with 0.8291 mm/yr and lastly 1.42284 mm/yr for CBA. In the same vein, reinforcing with PKSA yielded the highest polarization resistance with 1075.6 X and this was followed by the reinforcement of CSA with 564.4 X and CBA of 276.42 X. Ó 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 10th International Conference of Materials Processing and Characterization. 1. Introduction Powders reinforcements have played significant roles in the modification and enhancing the integrity of the properties of the parent materials in metal matrix composites (MMC), ceramic matrix composites (CMC) or polymer matrix composite (PMC). There are two main types of reinforcements that can be applied to enhance the properties of the base materials structurally, mechanically, metallurgically and electrochemically, and this can either come as inorganic (metallic) reinforcement powders or organic (basically agrowastes or industrial wastes) reinforcement powders. Several studies have shown that metallic reinforcement powders such as stainless-steel alloy, titanium alloy, oxides, silicon carbide, graphene, carbon nanotube, nitrides, iron, Aluminate, Boron, graphite, etc., have been used for several decades till date and these powders are not affordable and not easily available for researches. In the quest to go greener, young researchers have ven- tured into using materials that are environmentally friendly with low cost and readily available such as agriculture wastes, e.g. palm kernel shell ash, fly ash, rice husk ash, coconut shell ash and many others that will stand as remarkable preference to metal powders and at the same time offer promising properties that bestowed by the metallic reinforcement powders such as high strength, good corrosion and wear properties, improved hardness, etc. It has been established in the literature that very few works have been carried out using agrowastes powders as reinforcement either in friction stir processing, stir casting, and the like to improve properties. Dinahara et al. [1] used rice husk ask (RHA) and study its effects on surface enhancement and properties integ- rity. It was noted, reinforcing with RHA has significantly enhanced interfacial bonding and tensile properties in aluminium matrix composites (AMC) fabricated by friction stir processing (FSP). Kumar et al. [2] investigated the influence of fly ash on the copper alloy matrix through FSP. In this study, structural, tribological, mechanical and electrochemical properties were investigated. It was established that corrosion and wear behaviours were greatly improved with addition of fly ash. In the same vein, hardness and tensile properties were said to have improved tremendously. Several other researchers have employed fly ash as reinforcement https://doi.org/10.1016/j.matpr.2020.02.906 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 10th International Conference of Materials Processing and Characterization. ⇑ Corresponding author. E-mail address: oikumapayi@uj.ac.za (O.M. Ikumapayi). 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: O. M. Ikumapayi, E. T. Akinlabi, O. O. Abegunde et al., Electrochemical investigation of calcined agrowastes powders on friction stir processing of aluminium-based matrix composites, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.02.906