Process Optimisation and Tribological Behaviour Studies on Surface Modified Al 6061-T6 Alloy Deposited with WS2 Solid Lubricant Layer Through Electrical Discharge Approach

Abstract

In this present work, an attempt has been made to deposit the WS 2 layer on the Al 6061-T6 alloy surface through the electrical discharge deposition (EDD) technique. Specified deposition parameters, namely powder concentration (C p ), pulse-on time (P on ), and gap voltage (V g ) with various levels considered during the EDD process. The experimentation was performed for analysing the results of deposition parameters on material deposition rate (MDR), surface roughness (SR), microhardness (MH), layer thickness (LT), and surface characteristics of the WS 2 layer were examined. The results addressed the various intermetallic compounds formed on the deposited surface. A multi-objective optimisation using Box-Behnken design of response surface methodology was utilised to conduct the deposition process. To predict and optimise the appropriate MDR, SR, MH, and LT, the quadratic model was developed using regression analysis and analysis of variance. Based on the developed model, the interaction effects of deposition parameters on the EDD process were explored. The optimal depositing parameters are determined by maximising the MDR and MH and minimising the SR and LT. The validation test results confirm that experimental data are good in agreement with the predicted results, and hence, the model is feasible to predict the responses adequately. The tribological study was carried out for the optimised condition, and surface characteristics on the worn-out surface were analysed. When compared to the base material, the obtained results show a lower coefficient of friction and specific wear rate.

Numerical Simulation of the Coating Process of some Metals by Electrical Discharge Deposition

“…The maximum value obtained is in agreement with mean value of experimental data of EDD in air [14]. Fm= q (v0 x B) = q vp B sin α [N], (7) where: q is the electric charge [C]; vp -particle velocity [m/s]; B -magnetic flux density [T]; α -the angle between vp and B vectors directions. The localization of released particles (Np) after passing through magnetic field is represented by Poincaré maps in correspondence with the three cut planes previously defined -Fig.…”

“…For example, WS2 was deposited on an aluminum alloy (Al 6061-T6). The results pointed out that by coating, the friction coefficient was reduced, and the wear resistance was improved [7]. Another example was WC-Cu coating from powder compacted electrode on Mg alloy (AZ31B Mg) that improved the friction coefficient and the wear resistance.…”

Wear characteristics and sustainability of WS2 solid lubricant deposited layer on Al 6061-T6 substrate under the dry sliding conditions

“…WS 2 was deposited on an Al 6061-T6 surface to conduct the tribological study. The selected deposition criteria are 8.7 g/L of WS 2 concentration, 72 µs of spark-on time, and 23 V of gap voltage, as determined by previous research [21]. The macroscopic view of Al 6061-T6 sample before and after WS 2 deposition is shown in Figure 2 (b,c).…”

Electric discharge coating process: a critical review with potential application

“…They reported surface defects, existence elements, phase recognition and surface roughness of coated layer. Rajeshshyam R et al [105] developed a solid lubricant coating on aluminium alloy by powder mixed EDC and powder concentration influence on coat layer thickness and it ranges from 35 μm to 55 μm. Arun I et al [106] developed a powder mixed EDC of silicon powder on a steel substrate and reported that the coated layer thickness increases with increase of powder concentration.…”