Surface Topography-Metrology and Properties
·
2024
·Vol. 12
·期 1
·015005
·
IF 2
Jiaqi He,Huijian Li,Huajie Tang,Zihan Guo
Artificial intelligence algorithms including two artificial neural network and two machine learning algorithms were employed to predict the four-ball tribology behavior of MoS2-Al2O3 hybrid nanofluid. MoS2-Al2O3 composite nanoparticles were synthesized using solvothermal method and then dispersed in water-based fluids. 27 groups of tribology tests were conducted according to Box-Behnken experimental design were set as the training groups. The input variables (velocity of friction pairs, test force, test temperature, nanoparticle concentration) and output parameters (friction coefficient, wear scar diameter, wear surface roughness) were selected as the main variables. It was found that the random forest (RF) had better predict accuracy and stability for the four-ball tribology behavior of MoS2-Al2O3 nanofluid than multilayer perceptron (MLP), back propagation (BP) and k-nearest neighbors (KNN) algorithms. Besides, Pearson correlation analysis was carried out to reveal the relationship between input and output as well as different output variables. Through in-depth characterization of worn surface, a tribofilm in the thickness of 15 ∼ 20 nm composed of amorphous phases, ultra-fine nanoparticles and iron compounds was found. Finally, the lubrication mechanism of MoS2-Al2O3 nanofluid were discussed based on analyzing the tribology behavior data and tribofilm structure. Through the above findings, we hope to promote the application and development of artificial intelligence techniques in lubricants design and performance evaluation in the future.
研究领域:
材料科学
·
人工智能
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Jiaqi He,Jianlin Sun,Yanan Meng,Huajie Tang,Ping Wu
Nanofluids containing nanocomposite materials have broad application prospect in lubrication . In the present study, MoS 2 -Al 2 O 3 nanocomposite was synthesized by solvothermal method . Then water-based nanofluid containing MoS 2 -Al 2 O 3 nanoparticles was prepared and it exhibited optimal stability and wettability . The tribological properties of MoS 2 -Al 2 O 3 nanofluid under steel/steel contact were investigated. Through chemical analysis of worn surface, tribochemical reactions occurred and tribofilm generated at friction interface were studied to reveal the lubrication mechanism. The results showed that MoS 2 -Al 2 O 3 nanofluid exhibited outstanding effect on reducing the friction force and wear rate of friction pairs. The superior lubrication performance was partly attributed to the entry and movement of nanoparticles at friction interface. More importantly, due to interfacial tribochemistry , a tribofilm with double layer structure composed of adsorption film and reaction layer was formed on the metal surface , preventing the direct contact of steel surfaces. The adsorption film with a thickness of about 16 nm was predominated by amorphous substrates and crystal phases (ultrafine Al 2 O 3 and MoS 2 debris) embedded in the top. And the reaction layer beneath adsorption film contained high mechanical properties iron oxides (mainly Fe 3 O 4 and Fe 2 O 3 ) and self-lubricating Fe 2 (SO 4 ) 3 , which further alleviated friction and enhanced the wear-resistance of materials.
研究领域:
材料科学
·
摩擦学
·
化学工程
·
机械工程
✓ 已验证
DOI
高影响因子
CATALYSIS TODAY
·
2020
·
IF 5.825
Lei Wang,Haiyan Liu,Yu Fan,Pei Yuan,Deqi Huang,S. Ted Oyama,Tinghai Wang,Xiaojun Bao
In alumina-based catalysts the properties of the alumina support directly influence the structure (size, morphology, orientation, etc.) of the resulting active phase and ultimately determine the performance of the final catalysts. This paper presents a facile and efficient method for γ-Al 2 O 3 to simultaneously expose {111} facets with strong acidity and {110} facets with moderate basicity. It is shown that the metal oxides NiO x and MoO x can be selectively deposited and subsequently sulfided on the respective facets to form a NiS 2 -MoS 2 /Al 2 O 3 catalyst with substantially enhanced activity for thio-etherification reaction. By cooperative action of the active sites on the newly exposed facets, the catalyst is shown to have superior activity over a conventional NiMoS/Al 2 O 3 catalyst in the thio-etherification reaction between ethanethiol and isoamylene (2-methyl-2-butene) to yield ethylamyl thioethers. Our findings show that tuning the physicochemical properties via crystal facet engineering and inducing cooperative catalysis via preferential deposition of active metals open a novel avenue for the rational design and synthesis of high performance catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Manufacturing Processes
·
2020
·
IF 4.086
Jiaqi He,Jianlin Sun,Yanan Meng,Yu Pei
The novel composite material MoS 2 -Al 2 O 3 nanoparticles were synthesized via mussel-inspired chemistry of dopamine. Hot rolling lubrication performance of MoS 2 -Al 2 O 3 in water-based fluid was evaluated using a two-high rolling mill. Results showed that the synthesized MoS 2 -Al 2 O 3 nanofluid exhibited optimum hot rolling lubrication performance. The finish rolling thickness and rolled surface roughness reached lowest. Meanwhile the rolling force and oxide scale thickness of strips were respectively reduced by 26.9 % and 54.2 % compared with base-fluid lubricating condition. The ratio of Fe 2 O 3 in oxide scale has lowered when rolled with nanofluids, owing to the antioxidation effect of nanoparticles during lubrication. MoS 2 has partially oxidized to MoO 3 and the excellent lubrication performance of MoS 2 -Al 2 O 3 nanofluid resulted from the lubricating film formed by these three nanoparticles.
研究领域:
材料科学
·
机械工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Processes
·
2023
·Vol. 11
·期 11
·3181
·
IF 3.5
Chuangchuang Yang,Qiaoling Dai,Anpeng Hu,Hui Yuan,Qinghe Yang
In this present work, a new kind of sulfurized hydrodesulfurization catalyst was synthesized via the hydrothermal treatment of MoS2, NiCO3·2Ni(OH)2·4H2O, and Al2O3precursors, followed by annealing under a H2atmosphere, which does not require a sulfurization process compared to traditional preparation methods. The influence of the annealing temperature and the type of Al2O3precursor on the interactions between MoS2and Al2O3were studied using X-ray fluorescence spectroscopy, X-ray diffraction, N2adsorption–desorption, Raman spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The results indicated an increase in the number of stacked layers of the MoS2catalyst, accompanied by a decrease in the degree of decoration of Ni atoms onto MoS2nanoslabs, as a result of the strengthened MoS2–Al2O3interaction. Subsequently, the efficiency of hydrodesulfurization (HDS) was evaluated using dibenzothiophene as a representative reactant, while establishing a correlation between the structure of the catalyst and its performance. The catalysts, using pseudo-boehmite as the precursor and calcined at 500 °C, synthesized by calcining pseudo-boehmite as the precursor for Al2O3at a temperature of 500 °C and possessing suitable metal–support interactions, exhibited a reduced number of MoS2stacking layers and lateral dimensions, along with an optimal decoration degree of Ni atoms, thereby resulting in the highest level of HDS activity.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）