Volume 48, No 2, 2026, Pages 324-338
Download full text in PDFResponse Surface Modelling of Friction and Wear Behaviour of Nano-Enhanced Peltophorum Pterocarpum Biodiesel under Boundary Lubrication
Authors:
T. Dayananda Murthy 
,
H. Yogish ,
N.S. Kumaraswam ,
R. Pavankumar
DOI: 10.24874/ti.2168.03.26.06
Received: 30 March 2026
Revised: 6 May 2026
Accepted: 19 May 2026
Published: 15 June 2026
Abstract:
This work investigates the boundary lubrication behaviour of Peltophorum pterocarpum biodiesel enhanced with MoS₂ nanoparticles through statistically planned pin-on-disc experiments and response surface modelling. The biodiesel satisfied the principal ASTM D6751 and EN 14214 property limits considered in this study. MoS₂ nanoparticles with platelet/nanosheet morphology and 70-90 nm average particle size were dispersed at 0-150 ppm, while normal load and sliding speed were varied within 10-40 N and 0.25-1.00 m/s, respectively. A Box-Behnken design was used to model coefficient of friction (COF), wear rate, and post-test surface roughness for AISI 52100 steel contacts. COF and wear rate ranged from 0.094-0.132 and 2.30-4.20 x 10⁻⁶ mm³/N·m, respectively. ANOVA showed significant quadratic models for COF (R² = 0.945) and wear rate (R² = 0.902), with nano-additive concentration, load, and speed being the dominant factors. Confirmation testing at 135 ppm MoS₂, 12 N, and 1.00 m/s yielded 0.093 ± 0.002 COF, 2.34 ± 0.09 x 10⁻⁶ mm³/N·m wear rate, and 0.26 ± 0.01 µm roughness, corresponding to 3.33-4.00% absolute prediction errors. XRD and EDS results indicate a thin MoS₂-/oxide-/carbon-containing tribofilm, supporting a lubrication mechanism involving reduced metal-to-metal contact, lower shear at the interface, and partial filling or smoothing of surface asperities.
Keywords:
Biodiesel, MoS2 Nano-additive, Boundary lubrication, Response surface methodology coefficient of friction, wear rate
