International Journal of Surface Science and Engineering (7 papers in press)

Regular Issues

• Effect of nitrogen ion implantation dose on microstructure and mechanical properties of TiNiCu alloy for orthodontic applications  
  by Bohang Zhu, Jiaze Wang, Tianyi Zhao, Hongbo Liu, Dan Chen, Huimin Zhou 
  Abstract: To improve the clinical performance of TiNiCu orthodontic archwires, friction must be reduced without compromising superelasticity, thereby ensuring sustained force delivery. In this study, nitrogen ion implantation was employed to modify the alloy surface. The influence of implantation dose on its microstructure, tribological behaviour and superelastic stability was systematically investigated. Results showed that a nitride-rich modified layer formed near the surface, with the phase evolving from Ti2N to TiN as the dose increased. At 1.0-1.5 x 1018 ions/cm2 (10-15 h), the friction coefficient decreased by approximately 90% and the wear rate by 65.3%. The austenite finish temperature (Af) remained between 32 and 35 C, which is below the oral temperature, indicating a fully austenitic state during clinical use. This modification enhanced wear resistance and superelastic cyclic stability, thereby providing experimental guidance for developing low-friction TiNiCu orthodontic archwires.
  Keywords: TiNiCu alloy; nitrogen ion implantation; wear resistance; friction coefficient; cyclic stability; surface modification.
  DOI: 10.1504/IJSURFSE.2026.10080272
   
  
• Effect of machining parameters on surface integrity of brake lining based on pneumatic cutting method  
  by Canyue Jiang, Juan Hou, Lubo Zhen 
  Abstract: In order to investigate the cutting characteristics of brake lining and the crucial influence of machining parameters on surface integrity of the material, the pneumatic cutting method is presented. The experimental results show that the time-domain characteristic of the pneumatic cutting signal includes three distinct phases, and the verified mathematical model applying to evaluate the amplitude spectrum characteristics of the cutting force signals demonstrates the majority of the cutting energy concentrated below 1 Hz. Additionally, the minimum defect area in the cross-section can reach about 6.3% of the entire cross-sectional area by utilising the blade with thickness of 1.5 mm, which indicates that using the blade with the maximum thickness of 2 mm and hardness higher than 55.4 HRC would be beneficial to obtain better surface integrity of the brake lining cross-section in 1.8 s and to protect work health and environment.
  Keywords: surface integrity; brake lining; pneumatic cutting; mathematical model; amplitude spectrum.
  DOI: 10.1504/IJSURFSE.2026.10080658
   
  
• Tribological characteristics and wear mechanisms of alumina wollastonite reinforced resin-based dental composite  
  by Meetu Nag 
  Abstract: Dental composites are restorative materials designed to replicate the mechanical strength and aesthetic appearance of natural teeth. However, their performance is often limited by frictional damage during mastication. In this study, specimens were synthesised using a BisGMA-TEGDMA matrix with constant wollastonite loading and varying alumina content. Wear behaviour was evaluated using a pin-on-disc tribometer under varying normal load, sliding velocity, and sliding time. The specific wear rate was quantified and analysed using a Taguchi design of experiments and analysis of variance (ANOVA). The results shows that increasing alumina content reduces the SWR. Scanning electron microscopy of the worn surfaces indicates a transition from severe abrasive wear to relatively less wear. The optimised wear condition was achieved at 8 wt% alumina, 75 N normal load, 250 rpm sliding velocity, and 30 min sliding time. Overall, these findings demonstrate the effect of alumina and wollastonite fillers in enhancing the wear resistance.
  Keywords: dental composites; specific wear rate; wear mechanism; tribological characteriisation.
  DOI: 10.1504/IJSURFSE.2026.10080659
   
  
• ANN simulation for prediction of wear rate and coefficient of friction of Ni-P-TiO2 composite coated piston ring  
  by M. Malathi, J. Herbert Mabel, R. Rajendran 
  Abstract: This study explores the development and performance of nickel-phosphorus (Ni-P) coatings integrated with titanium dioxide (TiO2) submicron particles for piston ring applications. The composite coatings Ni-P/TiO2 were deposited on piston ring substrates using an electroplating technique, with the TiO2 concentration optimised to enhance surface properties. The coatings were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDAX) to examine the microstructure, phase composition, and elemental distribution. Mechanical properties such as wear resistance, coefficient of friction (CoF) and hardness were evaluated using tribological analysis and micro hardness testing. The results showed that adding TiO2 particles at a concentration of 10 g/L significantly enhanced the corrosion resistance, hardness, wear resistance, and CoF of the Ni-P composite coatings. However, increasing the concentration beyond this level led to a decrease in hardness, likely due to particle agglomeration. The artificial neural network (ANN) technique was applied to predict the wear rate and CoF of the Ni-P/TiO2 reinforced composite. This advancement suggests that Ni-P/TiO2 composite coatings can be effectively used to predict the wear rate and CoF of piston rings and thereby estimate the service life of the piston ring.
  Keywords: artificial neural network; ANN; electro-co-deposition; composite coating; nickel phosphorus; TiO2; wear.
  
  
• Comparative study of fretting behaviour of nickel-plated and tin-plated copper against brass  
  by Kyungmok Kim 
  Abstract: This article investigates fretting behaviour of tin-plated and nickel-plated copper against brass. Fretting damage is one of critical issues in an automotive battery busbar. Fretting tests with commercial tin-plated and nickel-plated copper busbars were conducted. Two different normal forces (2 N and 4 N) were applied to the contact surface. Frictional force, relative displacement, and electrical contact resistance were simultaneously measured. The energy-based friction coefficient was determined with dissipated energy and actual sliding distance. It was identified that at 2 N, the energy-based friction coefficient of a nickel-plated specimen was approximately 10.7% lower than that of the tin-plated one, while at 4 N, it was approximately 14.4% lower. Fretting tests were interrupted at a critical electrical contact resistance. Then, fretting wear lifetime was defined as the number of cycles at the critical value. It was demonstrated that the nickel-plated specimens exhibited approximately 104% and 131% higher lifetime per unit displacement than the tin-plated specimens at 2 N and 4 N, respectively.
  Keywords: fretting; copper busbar; electrical resistance; nickel-plating; tin-plating; energy-based friction coefficient.
  DOI: 10.1504/IJSURFSE.2026.10081482
   
  
• Water-based superhydrophobic coating based on ODTMS-modified SiO and in synergy with TCNTs/WEP  
  by Bin Du, Xiangtong Jian, Sainan Wang, Kenan Yang, Chenyuan Gao, Jijun Luo, Bangyong Sun, Shisheng Zhou 
  Abstract: Superhydrophobic coatings are promising for self-cleaning, anti-icing, and oil-water separation. However, traditional methods rely on fluorinated compounds and organic solvents, causing environmental pollution, while poor adhesion and low mechanical strength limit their durability. To address these issues, this study develops a fully water-based, fluorine-free coating using ODTMS-modified SiO2 nanoparticles for micro-nano roughness and TCNTs/WEP as an eco-friendly binder. The coating was spray-coated onto substrates, and the sponge was dip-coated. At an optimal 1:1 mass ratio, the coating achieved a water contact angle of 161.7? and retained 153.7? after 500 abrasion cycles, demonstrating excellent mechanical stability. The superhydrophobic sponge exhibited oil adsorption of 48.52-84.92 g/g and maintained > 98% separation efficiency over 20 cycles, and could adsorb both light and heavy oils. This work offers a green, durable, and scalable solution for oily wastewater treatment.
  Keywords: waterborne superhydrophobic coating; superhydrophobic sponge; coating performance; environmental protection; oil-water separation.
  DOI: 10.1504/IJSURFSE.2026.10081593
   
  
• Effects of pin shaft profile modification parameters on the lubrication performance of planetary journal bearings in wind turbine gearboxes  
  by Xudong Chen, Zhongying Xu, Liwen Wang 
  Abstract: Planetary journal bearings in wind turbine gearboxes often suffer from shaft misalignment, edge pressure concentration and asperity contact under low-speed, heavy-load operation. This study proposes a mixed-lubrication model incorporating shaft misalignment, pin-shaft end profile modification, asperity contact and elastic deformation. Hydrodynamic pressure is obtained from the average Reynolds equation, while asperity contact pressure is evaluated using the Greenwood-Williamson model. The influences of modification depth and index on film thickness, pressure and deformation are examined. Results show that end profile modification compensates for end film-thickness loss, shifts the pressure peak away from the axial edge, and substantially lowers edge contact risk. For the representative case with a modification depth of 15 m and a modification index of 1, the maximum contact pressure is reduced by about 95.47% compared with the unmodified bearing. An appropriate depth improves end lubrication, whereas excessive modification weakens the effective load-carrying region; a higher index confines modification to the ends while maintaining central load capacity.
  Keywords: wind turbine gearbox; planetary journal bearing; pin shaft profile modification; misalignment; mixed lubrication; G-W model.
  DOI: 10.1504/IJSURFSE.2026.10081594