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Tribological mechanism of carbon group nanofluids on grinding interface under minimum quantity lubrication

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0733-z

摘要: Carbon group nanofluids can further improve the friction-reducing and anti-wear properties of minimum quantity lubrication (MQL). However, the formation mechanism of lubrication films generated by carbon group nanofluids on MQL grinding interfaces is not fully revealed due to lack of sufficient evidence. Here, molecular dynamic simulations for the abrasive grain/workpiece interface were conducted under nanofluid MQL, MQL, and dry grinding conditions. Three kinds of carbon group nanoparticles, i.e., nanodiamond (ND), carbon nanotube (CNT), and graphene nanosheet (GN), were taken as representative specimens. The [BMIM]BF4 ionic liquid was used as base fluid. The materials used as workpiece and abrasive grain were the single-crystal Ni–Fe–Cr series of Ni-based alloy and single-crystal cubic boron nitride (CBN), respectively. Tangential grinding force was used to evaluate the lubrication performance under the grinding conditions. The abrasive grain/workpiece contact states under the different grinding conditions were compared to reveal the formation mechanism of the lubrication film. Investigations showed the formation of a boundary lubrication film on the abrasive grain/workpiece interface under the MQL condition, with the ionic liquid molecules absorbing in the groove-like fractures on the grain wear’s flat face. The boundary lubrication film underwent a friction-reducing effect by reducing the abrasive grain/workpiece contact area. Under the nanofluid MQL condition, the carbon group nanoparticles further enhanced the tribological performance of the MQL technique that had benefited from their corresponding tribological behaviors on the abrasive grain/workpiece interface. The behaviors involved the rolling effect of ND, the rolling and sliding effects of CNT, and the interlayer shear effect of GN. Compared with the findings under the MQL condition, the tangential grinding forces could be further reduced by 8.5%, 12.0%, and 14.1% under the diamond, CNT, and graphene nanofluid MQL conditions, respectively.

关键词: grinding     minimum quantity lubrication     carbon group nanofluid     tribological mechanism    

Study on tribological and electrochemistry properties of metal materials in H2O2 solutions

Chengqing YUAN, Li YU, Jian LI, Xinping YAN

《机械工程前沿(英文)》 2012年 第7卷 第1期   页码 93-98 doi: 10.1007/s11465-012-0313-8

摘要:

Hydrogen peroxide (H2O2) is a kind of ideal green propellant. It is crucial to study the wear behavior and failure modes of the metal materials under the strong oxidizing environment of H2O2. This study aims to investigate the wear of rubbing pairs of 2Cr13 stainless steel against 1045 metal in H2O2 solutions, which has a great effect on wear, the decomposition and damage mechanism of materials. The comparison analysis of the friction coefficients, wear mass loss, worn surface topographies and current densities was conducted under different concentrations of H2O2 solutions. There were significant differences in the tribological and electrochemistry properties of the rubbing pairs in different H2O2 solutions.

关键词: hydrogen peroxide     wear     corrosion     wear mechanism    

Facile synthesis of polyaniline nanorods to simultaneously enhance the mechanical properties and wear resistance of epoxy composites

《化学科学与工程前沿(英文)》 2023年 第17卷 第9期   页码 1254-1266 doi: 10.1007/s11705-023-2297-3

摘要: To enhance the mechanical properties and wear resistance of epoxy resin, polyaniline nanorods were first synthesized using a facile route, and then introduced into the epoxy matrix to yield composites via solution mixing. Several measurements were conducted to investigate the phase structures and compositions of polyaniline nanorods, and their positive influences on the mechanical and tribological properties of epoxy resin were also characterized. The results confirmed that the as-synthesized polyaniline exhibited representative rod-like morphologies and dispersed well in the epoxy matrix, leading to significant enhancements in the tensile strength and elastic modulus of epoxy composites. The highest values of 110.33 MPa and 2.04 GPa were obtained by adding 5%–7% polyaniline nanorods, which were 43% and 62% higher than the pure sample, respectively. The wear rate was increased first and then decreased along with polyaniline nanorods, presenting the lowest value of 2.12 × 10−5 mm3·Nm–1 by adding 5% filler, which was markedly reduced by ca. 70% compared to the control sample. Finally, the possible wear mechanism was proposed and discussed in detail. This study tried to broaden the applications of polyaniline nanorods in the field of tribology.

关键词: epoxy resin     polyaniline nanorods     mechanical property     tribological performance     wear mechanism    

Erratum to: Synthesis of hierarchical nanohybrid CNT@Ni-PS and its applications in enhancing the tribological

《化学科学与工程前沿(英文)》 2022年 第16卷 第10期   页码 1530-1530 doi: 10.1007/s11705-022-2240-5

Effect of electrolyte concentration on the tribological performance of MAO coatings on aluminum alloys

Chao Wang, Jun Chen, Jihua He, Jing Jiang, Qinyong Zhang

《化学科学与工程前沿(英文)》 2020年 第14卷 第6期   页码 1065-1071 doi: 10.1007/s11705-019-1909-x

摘要: Micro-arc oxidation (MAO) is an efficient approach to improve the hardness, wear resistance, and other properties of aluminum alloys. In order to investigate the effect of the electrolyte concentration on the properties of MAO coatings for LY12 alloy, the voltage variation during the MAO process was recorded. The surface morphologies and phase compositions of the coatings produced with different electrolytes were investigated using scanning electron microscopy and X-ray diffraction, respectively. The roughness and thickness of the coatings were measured using a pocket roughness meter and an eddy-current thickness meter, respectively. The tribological performances of the coatings were investigated against GCr15 bearing steel on a ball-on-disc wear tester in open air. The results showed that with an increase in the Na SiO content, the working voltage of the MAO process decreased, the roughness and thickness of the coatings increased significantly, and the relative content of the -Al O phase decreased. With an increase in the KOH content, the working voltage decreased slightly, the roughness and thickness of the coatings increased slightly, and the α- and -Al O phase contents remained unchanged. The friction coefficient and wear rate of the coatings increased with an increase in the Na SiO and KOH concentrations. A decrease in the porosity and roughness and an increase in the α-Al O content of the coatings reduced their wear mass loss.

关键词: aluminum alloy     micro-arc oxidation     coating     electrolyte concentration     tribological performance    

framework-derived whisker-shaped nickel phyllosilicate toward efficiently enhanced mechanical, flammable and tribological

《化学科学与工程前沿(英文)》 2022年 第16卷 第10期   页码 1493-1504 doi: 10.1007/s11705-022-2168-9

摘要: Metal−organic framework-derived materials have attracted significant attention in the applications of functional materials. In this work, the rod-like nickel-based metal−organic frameworks were first synthesized and subsequently employed as the hard templates and nickel sources to prepare the whisker-shaped nickel phyllosilicate using a facile hydrothermal technology. Then, the nickel phyllosilicate whiskers were evaluated to enhance the mechanical, thermal, flammable, and tribological properties of epoxy resin. The results show that adequate nickel phyllosilicate whiskers can disperse well in the matrix, improving the tensile strength and elastic modulus by 13.6% and 56.4%, respectively. Although the addition of nickel phyllosilicate whiskers could not obtain any UL-94 ratings, it enhanced the difficulty in burning the resulted epoxy resin nanocomposites and considerably enhanced thermal stabilities. Additionally, it was demonstrated that such nickel phyllosilicate whiskers preferred to improve the wear resistance instead of the antifriction feature. Moreover, the wear rate of epoxy resin nanocomposites was reduced significantly by 80% for pure epoxy resin by adding 1 phr whiskers. The as-prepared nickel phyllosilicate whiskers proved to be promising reinforcements in preparing of high-performance epoxy resin nanocomposites.

关键词: metal−organic framework     nickel phyllosilicate     whisker     epoxy resin     mechanical response     tribological performance     flammable property    

Synthesis of hierarchical nanohybrid CNT@Ni-PS and its applications in enhancing the tribological, curing

Jinian Yang, Yuxuan Xu, Chang Su, Shibin Nie, Zhenyu Li

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1281-1295 doi: 10.1007/s11705-020-2007-9

摘要: Poor interfacial adhesion and dispersity severely obstruct the continued development of carbon nanotube (CNT)-reinforced epoxy (EP) for potential applications. Herein, hierarchical CNT nanohybrids using nickel phyllosilicate (Ni-PS) as surface decorations (CNT@Ni-PS) were synthesized, and the nanocomposites derived from varied mass fractions of EP and CNT@Ni-PS were prepared. The morphological structures, tribological performances, curing behaviors and thermal properties of EP/CNT@Ni-PS nanocomposites were carefully investigated. Results show that hierarchical CNT nanohybrids with homogeneous dispersion and well-bonded interfacial adhesion in the matrix are successfully obtained, presenting significantly improved thermal and tribological properties. Moreover, analysis on cure kinetics proves the excellent promotion of CNT@Ni-PS on the non-isothermal curing process, lowering the curing energy barrier steadily.

关键词: nickel phyllosilicate     surface decoration     tribological property     curing kinetics     thermal performance    

Tribological study on the surface modification of metal-on-polymer bioimplants

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0682-6

摘要: The tribological performance of artificial joints is regarded as the main factor of the lifespan of implanted prostheses. The relationship between surface roughness and coefficient of friction (COF) under dry and lubricated conditions is studied. Results show that under dry test, friction coefficient is not reduced all the time with a decrease in surface roughness. On the contrary, a threshold of roughness value is observed, and frictional force increases again below this value. This critical value lies between 40 and 100 nm in Sa (roughness). This phenomenon is due to the transfer of friction mechanisms from abrasion to adhesion. Under wet test, COF always decreases with reduction in surface roughness. This result is mainly attributed to the existence of a thin layer of lubricant film that prevents the intimate contact of two articulating surfaces, thus greatly alleviating adhesion friction. Furthermore, surface texturing technology is successful in improving the corresponding tribological performance by decreasing friction force and mitigating surface deterioration. The even-distribution mode of texturing patterns is most suitable for artificial joints. By obtaining the optimal surface roughness and applying texturing technology, the tribological performance of polymer-based bioimplants can be greatly enhanced.

关键词: artificial joints     surface roughness     friction     surface texturing    

Application of Cu nanoparticles as N32 base oil additives

Qiang HE, Jun YE, Hongzhao LIU, Jinling LI,

《机械工程前沿(英文)》 2010年 第5卷 第1期   页码 93-97 doi: 10.1007/s11465-009-0083-0

摘要: Cu nanoparticles as N32 base oil additives are studied in the paper and their structure is characterized by transmission electron microscopy (TEM) and X-ray powder diffraction spectroscopy (XRD). The widely used steel-steel friction system is chosen to test the feasibility and practicality of Cu nanoparticles as bearing lubricant additives. The results show that N32 base oil with 0.5% Cu nanoparticle can improve the test sample contact fatigue life than pure N32 base oil.

关键词: Cu nanoparticle     tribological property     contact fatigue     weibull distribution    

Tribological properties of onion like fullerenes and NiFe

Ruixiang WANG,Yihao ZHANG,Haizhou WU

《能源前沿(英文)》 2021年 第15卷 第1期   页码 208-212 doi: 10.1007/s11708-017-0454-x

摘要: A novel way for a compressor to improve its coefficient of performance and enhance its reliability by employing nano-refrigeration lubricant oil was proposed. Onion like fullerenes (OLFs) and NiFe O nano-composites, modified by Span 80, were dispersed in refrigeration oil KFR22 by solid grinding (SG). Morphologies of NiFe O nano-composites were characterized by using transmission electron microscope (TEM). The tribological properties as a refrigeration lubricants additive were investigated using SRV (II), a multi-functional reciprocating friction and wear tester. The results showed that the friction coefficient was decreased from 0.15 to 0.04.

关键词: refrigeration lubricants     friction coefficient     nano-composites     reciprocating motion     onion like fullerenes    

Self-sacrificial templating synthesis of flower-like nickel phyllosilicates and its application as high-performance reinforcements in epoxy nanocomposites

《化学科学与工程前沿(英文)》 2022年 第16卷 第4期   页码 484-497 doi: 10.1007/s11705-021-2074-6

摘要: The nanocomposites of flower-like nickel phyllosilicate particles incorporated into epoxy resin were fabricated via an in-situ mixing process. The flower-like nickel phyllosilicate particles were firstly synthesized using a mild self-sacrificial templating method, and the morphology and lamellar structure were examined carefully. Several properties of mechanical, thermal and tribological responses of epoxy nanocomposites were performed. It was demonstrated that adequate flower-like nickel phyllosilicate particles dispersed well in the matrix, and the nanocomposites displayed enhanced tensile strength and elastic modulus but decreased elongation at break as expected. In addition, friction coefficient and wear rate were increased first and then decreased along with the particle content, and showed the lowest values at a mass fraction of 5%. Nevertheless, the incorporated flower-like nickel phyllosilicate particles resulted in the continuously increasing thermal stability of epoxy resin (EP) nanocomposites. This study revealed the giant potential of flower-like particles in preparing high-quality EP nanocomposites.

关键词: nickel phyllosilicate     flow-like structure     mechanical property     thermal stability     tribological performance    

Theory and method of mechanism system design

Huijun ZOU, Qinghua LIANG, Qing ZHANG

《机械工程前沿(英文)》 2010年 第5卷 第4期   页码 399-411 doi: 10.1007/s11465-010-0116-8

摘要: Conceptual design is the most critical and creative phase of design. Recently, increasing attention has been directed to supporting conceptual-level computer aided creative design and its theories and methodologies. Specifically, for conceptual design of mechanical products, this paper presents a novel function solving model for mechanical product design and highlights the importance of systematic synthesis to achieve creative design. Then it builds a framework as a function-effect-process-action- mechanisms (FEPAM) mapping process, which enables creative design on the basis of conceiving different action schemes. After that, several key points are elaborated including 1) representing and decomposition methods of functions and motion behaviors; 2) action scheme representing method based on network plan techniques; and 3) variation and creation methods based on action scheme transformations.

关键词: mechanism system creative design     process model     function solving model     process action procedure     mechanisms knowledge base     principle of mechanism system composition    

Formation mechanism and modeling of surface waviness in incremental sheet forming

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0679-1

摘要: Improving and controlling surface quality has always been a challenge for incremental sheet forming (ISF), whereas the generation mechanism of waviness surface is still unknown, which impedes the widely application of ISF in the industrial field. In this paper, the formation mechanism and the prediction of waviness are both investigated through experiments, numerical simulation, and theoretical analysis. Based on a verified finite element model, the waviness topography is predicted numerically for the first time, and its generation is attributed to the residual bending deformation through deformation history analysis. For more efficient engineering application, a theoretical model for waviness height is proposed based on the generation mechanism, using a modified strain function considering deformation modes. This work is favorable for the perfection of formation mechanism and control of surface quality in ISF.

关键词: surface waviness     incremental sheet forming     numerical simulation     formation mechanism     deformation history    

Autogenous healing mechanism of cement-based materials

《结构与土木工程前沿(英文)》   页码 948-963 doi: 10.1007/s11709-023-0960-3

摘要: Autogenous self-healing is the innate and fundamental repair capability of cement-based materials for healing cracks. Many researchers have investigated factors that influence autogenous healing. However, systematic research on the autogenous healing mechanism of cement-based materials is lacking. The healing process mainly involves a chemical process, including further hydration of unhydrated cement and carbonation of calcium oxide and calcium hydroxide. Hence, the autogenous healing process is influenced by the material constituents of the cement composite and the ambient environment. In this study, different factors influencing the healing process of cement-based materials were investigated. Scanning electron microscopy and optical microscopy were used to examine the autogenous healing mechanism, and the maximum healing capacity was assessed. Furthermore, detailed theoretical analysis and quantitative detection of autogenous healing were conducted. This study provides a valuable reference for developing an improved healing technique for cement-based composites.

关键词: autogenous healing     cement-based materials     healing mechanism     aggregation effect    

Optimal design of a linkage–cam mechanism-based redundantly actuated parallel manipulator

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 451-467 doi: 10.1007/s11465-021-0634-6

摘要: A redundantly actuated parallel manipulator (RAPM) with mixed translational and rotational degrees of freedom (DOFs) is challenged for its dimensionally homogeneous Jacobian modeling and optimal design of architecture. In this paper, a means to achieve redundant actuation by adding kinematic constraints is introduced, which reduces the DOFs of the end-effector (EE). A generic dimensionally homogeneous Jacobian is developed for this type of RAPMs, which maps the generalized velocities of three points on the EE to the joint velocities. A new optimization algorithm derived from this dimensionally homogeneous Jacobian is proposed for the optimal design of this type of RAPMs. As an example, this paper presents a spatial RAPM involving linkages and cam mechanisms. This RAPM has 4 DOFs and 6 translational actuations. The linkage lengths and the position of the universal joints of the RAPM are optimized based on the dimensionally homogeneous Jacobian.

关键词: redundant actuation     parallel manipulator     linkage–cam mechanism     Jacobian     optimal design    

标题 作者 时间 类型 操作

Tribological mechanism of carbon group nanofluids on grinding interface under minimum quantity lubrication

期刊论文

Study on tribological and electrochemistry properties of metal materials in H2O2 solutions

Chengqing YUAN, Li YU, Jian LI, Xinping YAN

期刊论文

Facile synthesis of polyaniline nanorods to simultaneously enhance the mechanical properties and wear resistance of epoxy composites

期刊论文

Erratum to: Synthesis of hierarchical nanohybrid CNT@Ni-PS and its applications in enhancing the tribological

期刊论文

Effect of electrolyte concentration on the tribological performance of MAO coatings on aluminum alloys

Chao Wang, Jun Chen, Jihua He, Jing Jiang, Qinyong Zhang

期刊论文

framework-derived whisker-shaped nickel phyllosilicate toward efficiently enhanced mechanical, flammable and tribological

期刊论文

Synthesis of hierarchical nanohybrid CNT@Ni-PS and its applications in enhancing the tribological, curing

Jinian Yang, Yuxuan Xu, Chang Su, Shibin Nie, Zhenyu Li

期刊论文

Tribological study on the surface modification of metal-on-polymer bioimplants

期刊论文

Application of Cu nanoparticles as N32 base oil additives

Qiang HE, Jun YE, Hongzhao LIU, Jinling LI,

期刊论文

Tribological properties of onion like fullerenes and NiFe

Ruixiang WANG,Yihao ZHANG,Haizhou WU

期刊论文

Self-sacrificial templating synthesis of flower-like nickel phyllosilicates and its application as high-performance reinforcements in epoxy nanocomposites

期刊论文

Theory and method of mechanism system design

Huijun ZOU, Qinghua LIANG, Qing ZHANG

期刊论文

Formation mechanism and modeling of surface waviness in incremental sheet forming

期刊论文

Autogenous healing mechanism of cement-based materials

期刊论文

Optimal design of a linkage–cam mechanism-based redundantly actuated parallel manipulator

期刊论文