Load dependence of oxidative wear in metal/ceramic tribocouples in fretting environment

Abstract

a b s t r a c tFor a large number of non-oxide ceramic/metal as well as for non-oxide particulate reinforced composite/metal tribocouples, oxidative wear is reported to play a major role in the overall damage and material removal process. The designing of new materials with improved resistance to oxidative wear requires understanding of the combined effect of the material properties and operating parameters on the wear resistance. In this paper, an analytical model to predict the dependence of the oxidative wear volume on load and sliding velocity is presented. The model is developed using basic chemical kinetics and Hertzian contact mechanics, and is valid for the case of a stable oxide layer. Exponential dependence of wear volume on operating parameters (load, sliding velocity) is predicted in the proposed model. It has been shown to successfully explain the qualitative experimental load dependence of the wear volume for five ceramic/metal tribocouples (Al 2 O 3 /steel, WC-TiC-Co/steel, TiB 2 -MoSi 2 /steel, ASP23 steel/alumina and Ti6Al4V/alumina) that exhibit oxidative wear. The activation energy of the oxidation of metallic counter bodies under fretting conditions was also calculated using the model, which turns out to be significantly lower than in the static conditions.

Wear behaviour and mechanism of different metals sliding against stainless steel counterface

“…9–11 As a result, understanding the wear and frictional behaviour of the metals are confusing and incomparable since operating parameters have significant influence on the wear and frictional behaviour of metals under dry or wet (lubricant) contact conditions. 12–16 In Prasad, 13 friction and wear behaviour of grey cast iron was investigated under different test parameters, i.e. applied load, sliding speed and test environment and the results revealed that the wear loss increases with the sliding velocity and/or applied load increase.…”

Wear Maps and Models in Tribological Damage Analysis of Si3N4 Ceramics with Special Attention to Tribochemical Wear

“…Attempts to develop physically based wear models for ceramics represent a general trend of the direction of future developments. This is shown by the analytical models suggested recently by Tewari et al [51,52]. For high loading fretting conditions a tribochemical wear model (Model 16. in Table. 1.)…”

“…4.) accounting for the thermally activated tribochemical process as suggested by Tewari [52] (see Model 17. in Table. 1. This term introduces the absolute ambient temperature (Ta), the complex modulus (E*) of the friction couple and the thermal conductivity of the disc (kth), the complex radius of the tribocouple (R*), the friction coefficient () and the sliding velocity (v) as the most important factors influencing the rate of the tribochemical process.…”

Tribological Characteristics of Commercial Metals

“…However, the demand for further studies is enormous as there are numerous applications for metals like aluminium, mild steel and copper. The operating parameters have like sliding distance, sliding velocity, applied load, temperature developed at the interface influence the wear mechanism and frictional performance of the materials (Prasad, 2011;Kumar and Bijwe, 2011;Alotaibi et al, 2014b;Tewari, 2012;Yousif, 2013). Kumar and Bijwe (2011) investigated the frictional behavior and wear characteristics of cast iron and found that the progressive loss of material from the surface due to wear increases with increase in applied load.…”