TRIBOLOGY INTERNATIONAL
·
2021
·
IF 4.872
Na Wang,Honggang Wang,Junfang Ren,Gui Gao,Gengrui Zhao,Yawen Yang,Jinqing Wang
Environmental-friendly polytetrafluoroethylene@silica (PTFE@SiO 2 ) composite particles characterized by core-shell structure were synthesized. The tests demonstrated that the synthesized particles had good dispersibility and stability in poly-α-olefin 6 (PAO6) and its corrosion resistance was better than zinc dialkyl dithiophosphate (ZDDP). The extreme pressure (EP) and tribological tests evidenced that PTFE@SiO 2 particles possessed superior EP and anti-wear (AW) properties, which could enhance the wear-resistance and load-bearing capacities of PAO6 in high efficiency, whereas the tribological performance was greatly affected by the load. Besides, EP tests for different kinds of base oils demonstrated that the addition of PTFE@SiO 2 particles could significantly improve the bearing capacity of these base oils, and the corresponding performances were also better than ZDDP. Scanning electron microscope and X-ray photoelectron spectrum characterizations proved that there was an organic-inorganic co-extruded transfer film generated on the worn surface, and a possible lubrication mechanism on this basis was also put forward.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2026
·
IF 7.6
Na Hu,Yilong Ren,Yao Wu,Gaoyu Wang,Ping Chen,Yi Zhang
Stress-triggered MoS 2 /PAO6@UF microcapsules enabled high-load PTFE/epoxy liners with stable lubrication under step-loading up to 7.5 kN. • MoS₂ fraction tuned friction–wear performance, achieving 0.056 COF and 6.4 × 10 -8 wear rate. • A dynamic lubrication interface consisting of PAO6 oil film, MoS 2 solid film, and PTFE transfer film was revealed. Self-lubricating spherical plain bearings are key components in aircraft flight-control systems, and their moldable liners must provide stable lubrication under high-load conditions. However, it remains challenging to achieve low friction, low wear, and durable transfer-film protection in epoxy-based self-lubricating liner materials. In this study, Stress-triggered solid–liquid microcapsules consisting of a polyalphaolefin (PAO6)/MoS₂ lubricant core and a urea–formaldehyde (UF) shell were fabricated by in situ polymerization and subsequently incorporated with polytetrafluoroethylene (PTFE) into an epoxy matrix to prepare self-lubricating liner composites. The resulting microcapsules were denoted as MoS₂/PAO6@UF microcapsules. The microcapsules showed spherical morphologies, an average particle size of 6–7 μm, and good thermal stability below 200 °C. Under 1500 N and 100 rpm, the composite containing 5 wt.% MoS 2 in the microcapsule core exhibited the lowest coefficient of friction of 0.056, whereas the composite containing 10 wt.% MoS 2 achieved the lowest wear rate of 6.4 × 10 -8 mm 3 /(N·m). Step-loading tests showed that the composites maintained effective lubrication up to 6.5–7.5 kN, indicating good high-load-bearing capability. Optical microscopy, FTIR, XPS, and Raman analyses confirmed the formation of a composite lubricating interface composed of released PAO6, a PTFE transfer film, and a MoS 2 solid lubricating film. The PAO6 oil film reduced interfacial shear, the PTFE transfer film stabilized the lubricating interface, and the MoS 2 solid lubricating film provided load-bearing support. These results establish a stress-triggered, three-component lubrication strategy for high-load, moldable epoxy liners.
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Ruichen Zhang,Luyao Wang,Chunjian Duan,Shengmao Zhang,Liyong Niu,Pingyu Zhang,Zhijun Zhang,Seeram Ramakrishna,Chuanping Gao
The service life of self-lubricating spherical plain bearing (SLSPB) is heavily dependent on tribological property of polymeric liner between inside and outer ring. To meet urgent needs, such as ultra-long service life and harsher working conditions, enhancing SLSPB liner's tribological property is an effective option. Herein, different from conventional microcapsules, a novel nanocapsule containing nano-oil was successfully prepared mainly based on excellent tribological performance of Poly alpha olefin (PAO6, base oil) containing copper nanoparticles (Cu NPs) and pore canal and slow-release advantage of hollow mesoporous silicon nanocapsules (HMSNCs, hm -SiO 2 NCs). The results show that as-prepared PAO6/Cu@ hm -SiO 2 NCs have an average diameter of ∼150 nm and a content of 40 wt% Cu-nano-oil; when its content is 15 wt%, friction coefficient (COF) and wear rate ( W R ) of Epoxy resin (EP, as basic material of SLSPB) can be reduced by 88 % (0.74 → 0.09) and 99 % (47.312 × 10 −6 mm 3 /Nm to 0.646 × 10 −6 mm 3 /Nm), respectively. For one thing, such results have a close relationship with a synergistic effect among nano-oil, hm -SiO 2 NPs and EP resin. For another, a high-performance tribofilm with a gradient structure also plays a critical role, and this structure is closely associated with the size effect of DDP-Cu NPs, hm -SiO 2 nanoparticles, and PAO6/Cu@ hm -SiO 2 NCs. The corresponding tribological mechanism is also systematically investigated according to various surface and chemical analyses. The findings may pave a new strategy to enhance tribological property of polymer-based rubbing pairs, and contribute to designing a high-performance (such as ultra-long serve life, superior tribological performance, etc.) SLSPB liner.
研究领域:
材料科学
·
摩擦学
·
聚合物复合材料
·
纳米材料
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Siyuan Wang,Zhao Liang,Ling Liu,Yucheng Cao,Yingliang Cheng,Ding Chen
Despite being regarded as one of the most promising lubricant additives, poor dispersion remains a huge obstacle for graphene applications. To solve this problem, the traditional method is to modify graphene with chemical functionalization under harsh conditions. The present investigation prepared modified reduced graphene oxide by the traditional method (MRGO-1) and microwave-assisted ball milling (MRGO-2). The chemical and structural features of MRGO-1 and MRGO-2 are examined by SEM, TEM, XRD, Raman, FTIR, and TGA analyses. The results indicate the microwave-assisted ball milling enables MRGO-2 to be more efficiently dispersed and functionalized than MRGO-1. MRGO-1 and MRGO-2 were introduced into poly alpha-olefin oil (PAO6) as lubricant additives, and the dispersion and tribological performances were tested. Compared with MRGO-1, the dispersion stability of MRGO-2 is increased by 73.8%. Due to its excellent dispersion performance, MRGO-2 can consistently maintain a low friction coefficient during the friction process, and the average friction coefficient is 49.01% lower than that of MRGO-1. Furthermore, the EDS on the worn area demonstrates the most efficient transfer of MRGO-2 on the friction contact interfaces. Finally, the reasons for the improvement in dispersion stability and tribological properties of graphene by microwave-assisted ball milling are explained.
研究领域:
材料科学
·
化学工程
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2023
·
IF 11.1
Youheng Wang,Xianjun Hou,Longxiang Zhang,Mohamed Kamal Ahmed Ali,Hua Jiang,Yuxin Ma
Nano-materials, given their excellent anti-friction and anti-wear characteristics, have attracted significant attention in tribological applications. However, conventional nano-materials have difficulty meeting the development requirements of the eco-friendly lubricants . In this study, nano biochar derived from sesame stalk was synthesized and used as a lubricant additive in poly-alpha olefin-6 (PAO6). The tribological properties were evaluated by four ball tribological tests with steel and ceramic balls as the friction pair . Following the friction experiment, the worn surface on the steel ball was analyzed by X-ray photoelectron spectrometry . The steel ball friction results showed that the lubricants containing 0.2 wt% nano biochar achieved a maximum wear volume reduction of 46% compared to PAO6, and the friction coefficient decreased by 34.6% for the ceramic balls. Analysis indicated that the enhanced wettability of nano biochar lubricant contributed to improving the anti-wear properties. Characterization of the worn surface revealed that the addition of nano biochar facilitated the formation of strong Fe 3 O 4 tribofilms. This study demonstrated that nano biochar could serve as an environmentally friendly additive in the liquid lubricant industry.
研究领域:
材料科学
·
摩擦学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 8
·2126
·
IF 5.076
Yanjie Chen,Enzhu Hu,Hua Zhong,Jianping Wang,Ayush Subedi,Kunhong Hu,Xianguo Hu
Graphene has been widely used as a lubricating additive to reduce the energy consumption of engines and improve fuel economy because of its unique crystal structure. Herein, graphene (GR) and fluorinated graphene (F-GR) nanoparticles were prepared by ball milling and liquid-phase exfoliation. The SEM/EDS, HRTEM, XPS, Raman spectrometer, X-ray spectrometer, FTIR were used to investigate the morphologies, surface groups, and crystal structure of two kinds of graphene materials. The influence of loads on the tribological properties of two kinds of particles was investigated in Poly Alpha Olefin (PAO6) using a UMT-2 reciprocating tribometer. Results showed that the crystal structure of GR is better than F-GR. F-GR can improve the lubrication performance of PAO6. For PAO6 containing 1 wt% F-GR at 10 N, the average friction coefficient and average wear rate decreased by 12.3% and 87% relative to pure PAO6, respectively. However, the high load resulted in an inconspicuous anti-wear and anti-friction effect. The influence of F-GR on the tribological behavior of PAO6 was more substantial than that of GR. The friction and wear mechanisms attributed to F-GR quickly entered the interface between the friction pairs. Friction-induced F-GR nanosheets mainly took the tribo-chemical reactions to participate in the lubrication film formation and helped achieve a low friction coefficient and wear rate.Keywords:friction modifiers;solid lubricant additives;fluorocarbons;friction mechanisms
研究领域:
材料科学
·
摩擦学
·
纳米技术
·
润滑剂
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）