Wear studies of spark plasma sintered ZrO 2 reinforced Ti-6Al-4V alloy Lerato Semetse a , Babatunde Abiodun Obadele a,b , Lerato Raganya a,c , Peter Apata Olubambi a a Centre for Nanoengineering and Tribocorrosion, School of Mining, Metallurgy and Chemical Engineering, University of Johannesburg, Doornfontein Campus, Johannesburg 2094, South Africa b Department of Chemical, Materials and Metallurgical Engineering, Botswana International University of Science and Technology, Palapye, Botswana c Light Metals, Materials Science & Manufacturing, Council for Scientific and Industrial Research, Meiring Naudé Road, Brummeria, Pretoria 0185, South Africa article info Article history: Received 4 October 2019 Accepted 10 October 2019 Available online xxxx Keywords: Ti-6Al-4V Composites ZrO 2 Spark plasma sintering Wear Microhardness abstract The aim of this paper is to investigate wear and tribological properties of powder metallurgy processed Ti-6Al-4V with additions of ZrO 2 to produce Ti-6Al-4V/ZrO 2 composites consolidated via spark plasma sintering. The spark plasma sintered compacts were examined using optical microscopy (OM) and scan- ning electron microscopy (SEM) techniques. Dry sliding wear tests were carried out at 5 N and 10 N using a pin-on-disk tribometer. Optical micrographs showed that additions of ZrO 2 to Ti-6Al-4V promoted the formation of agglomerated ZrO 2 -rich particles in the matrix of Ti-6Al-4V. The friction coefficient values were very similar for all compositions, with values ranging between 0.35 and 0.55, with the lowest COF value recorded for Ti6Al4V/5ZrO 2 composite at 10 N applied load. Wear and microhardness results indicate that the hardness and the wear resistance improved with increasing content of ZrO 2 . The lowest surface degradation was observed for Ti-6Al-4V with 10% ZrO 2 . The low wear resistance of Ti-6Al-4V in comparison to Ti-6Al-4V/ZrO 2 composites can be attributed to the low hardness of this alloy. Adding ZrO 2 to Ti-6Al-4V was found to significantly improve the wear and hardness properties of Ti-6Al-4V and may therefore potentially broaden the scope of application and performance of Ti-based materials in critical applications; particularly where wear and friction are critical concerns. Ó 2019 Copyright Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 2nd International Conference on Recent Advances in Materials & Manufacturing Technologies. 1. Introduction Titanium and titanium alloys are known to be very strong, light- weight materials with excellent corrosion resistance; making them choice materials in aircraft parts, implants, heat exchangers, sport- ing equipment, power plants and automotive parts. Properties of titanium are largely dependent on their structure and can thus be grouped into four key categories of alpha, near alpha, a + b and beta structures. Alloying elements like aluminum, vanadium, iron, zirconium, tantalum, molybdenum and many others are com- monly added to titanium to manipulate its structure and proper- ties for various applications. Ti-6Al-4V is an a + b alloy of titanium, containing 6 wt% aluminum and 4 wt% vanadium. This alloy is the most widely used alloy of titanium, accounting for close to 50% usage of all titanium alloys. The aerospace industry accounts for the widest use of Ti-6Al-4V alloy because of its high strength to weight ratio and good high temperature properties. Furthermore, the good corrosion resistance of this alloy makes it incredibly useful in the marine and biomedical fields [1,2]. Many other alloys of titanium and titanium matrix composites are cur- rently being developed to widen the scope of titanium-based materials. Titanium-based materials are reported to have some limitations such as poor wear resistance and limited applicability beyond certain service temperatures [3,4]. Some of these factors have inspired ongoing research in developing new alloys and com- posites based on titanium, employing various processing tech- niques and emerging technologies [5–11]. Reinforcing titanium with second-phase particles to form tita- nium matrix composites (TMCs) has been found to significantly improve its properties. Maseko et al. [12] developed Ti-xZrB 2 com- posites using powder metallurgy and spark plasma sintering (SPS) technique in a bid to improve the hardness of this material for bal- listic applications and for potential use as an armour material. Maja et al. [13] conducted nanoindentation studies of Ti-6Al-4V matrix composites reinforced with TiN. It was discovered that the addition of TiN altered the microstructural morphology, which https://doi.org/10.1016/j.matpr.2019.10.033 2214-7853/Ó 2019 Copyright Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 2nd International Conference on Recent Advances in Materials & Manufacturing Technologies. 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: L. Semetse, B. A. Obadele, L. Raganya et al., Wear studies of spark plasma sintered ZrO 2 reinforced Ti-6Al-4V alloy, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.10.033