Xiaoliang Liu, Gai Zhao and Jinhao Qiu
The purpose of this paper is to investigate the effect of laser surface texturing on the tribological properties of polyimide composites and the output performance of traveling…
Abstract
Purpose
The purpose of this paper is to investigate the effect of laser surface texturing on the tribological properties of polyimide composites and the output performance of traveling wave rotary ultrasonic motor.
Design/methodology/approach
The surface texturing on polyimide composites specimens were fabricated by laser ablation process of different dimple densities, and then the tribological properties were tested by a flat-on-flat tribometer under dry conditions. Finally, the output performance of the traveling wave rotary ultrasonic motor was tested to verify the effectiveness of dimples surface texturing.
Findings
The results show that surface texturing can greatly enhance the friction coefficient of contact interface, especially the specimen with a dimple density of 7.06 per cent exhibited the highest friction coefficient among the specimens. When the input voltage is 500 V, the output power, locked-rotor torque and output torque of ultrasonic motor with textured PI of 7.06 per cent dimple density as friction material at the speed of 100 r/min increased by 13.8, 19 and 12.8 per cent compared to that of the untextured PTFE, respectively. When the ultrasonic motor reverses, the output performance is increased by 20.9, 40.3 and 17.7 per cent, respectively.
Originality/value
Surface texturing is an effective way to improve the friction behavior of polyimide composites and then correspondingly enhance the energy conversion efficiency and output performance of the traveling wave rotary ultrasonic motor.
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Xiaoliang Liu, Jinhao Qiu and Gai Zhao
This paper aims to investigate the effect of frictional materials and surface texture on the energy conversion efficiency and the mechanical output performance of the ultrasonic…
Abstract
Purpose
This paper aims to investigate the effect of frictional materials and surface texture on the energy conversion efficiency and the mechanical output performance of the ultrasonic motor (USM).
Design/methodology/approach
A newly designed testing system was set up to measure the mechanical output performance of the USM. The influence of different frictional materials on the output performance of the USM was studied under the same assembly process and parameters. The surface texture was fabricated by laser ablation processing. The effects of surface texture and input parameters on the energy conversion efficiency and mechanical output performance of the USM were studied.
Findings
The results show that polyimide (PI) composites as frictional material can significantly improve the output performance of the USM compared to polytetrafluoroethylene (PTFE) composites. When the pre-load is 240 N, the energy conversion efficiency of the USM using textured PI composites as frictional material can reach 41.93 per cent, increased by 29.21 per cent compared to PTFE composites, and the effective output range of the USM is increased to 0.7-1.1 N m. Besides, the pre-load and surface texture have a great influence on the output performance of the USM.
Originality/value
PI composites can improve the mechanical output performance of the USM. Surface texture can also improve the interface tribological properties and the energy conversion efficiency based on the advanced frictional materials, which will contribute to the increment of the output performance of the USM under the same input conditions.
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Yuanhao Yu, Jingfu Song, Gai Zhao and Qingjun Ding
This paper aims to study the effect of different rare earth oxide on the tribological properties of polyimide (PI) nanocomposites based on the CNT and GO reinforcements.
Abstract
Purpose
This paper aims to study the effect of different rare earth oxide on the tribological properties of polyimide (PI) nanocomposites based on the CNT and GO reinforcements.
Design/methodology/approach
The PI nanocomposites filled with different rare earth oxide based on the carbon nanotubes and graphene oxide were designed and prepared by hot press sintering. The mechanical and tribological properties of PI nanocomposites were carried out, and their reinforcement mechanisms were discovered.
Findings
Rare earth oxide had a weak influence on the impact strength of PI nanocomposites. Filling La2O3 can dramatically reduce the friction coefficient and wear rate of PI nanocomposites.
Originality/value
The PI nanocomposites filled with rare earth oxide based on the CNT and GO reinforcements were designed, and their mechanical and tribological properties were studied.
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Qingjun Ding and Gai Zhao
The purpose of this paper is to study the mechanism and effect of rare earth oxides on the properties of Cr2O3-TiO2 coating.
Abstract
Purpose
The purpose of this paper is to study the mechanism and effect of rare earth oxides on the properties of Cr2O3-TiO2 coating.
Design/methodology/approach
Cr2O3-TiO2 coatings with different proportion of CeO2 were deposited by atmospheric plasma spraying on aluminum alloy 7005. The mechanical, microstructure and tribological properties were studied.
Findings
The addition of CeO2 could improve the micro-hardness; decrease porosity, wear rate and surface roughness of the coating; and increase the bonding strength between the coating and substrate. The wear mechanism is a mixture of abrasive and adhesive wear.
Originality/value
The addition of CeO2 could refine microstructure, and promote the formation of solid solution structure, and then affect the properties of coatings.
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Qingjun Ding, Bo Tian, Gai Zhao, Feng Wang, Huafeng Li and Yunlai Shi
This study systematically investigated the effect of the binary rare earth oxide of La2O3 and Sm2O3 on the properties of the Al2O3/TiO2 (AT) coating, including phase transform…
Abstract
Purpose
This study systematically investigated the effect of the binary rare earth oxide of La2O3 and Sm2O3 on the properties of the Al2O3/TiO2 (AT) coating, including phase transform, wear behavior, etc.
Design/methodology/approach
AT coatings mixed with different components of binary rare earth oxides of La2O3 and Sm2O3 are prepared by atmospheric plasma spraying. The adhesion strength, micro-hardness, phase transition and tribological behavior of coatings are systematically investigated.
Findings
The X-ray diffraction (XRD) analysis shows that phase transformation is obvious after spraying, and a-Al2O3 is almost translated into γ-Al2O3 when La2O3 and Sm2O3 are doped together. Meanwhile, solid solution generated between rare earth oxide and Al2O3/TiO2 coatings results in disappearance of TiO2 and rare earth oxide phase. The photos under the scanning electron microscope (SEM) indicate that binary rare earth oxide could increase the melting degree of powder and decrease porosity of coatings.The increasing of Sm2O3 rarely affect micro-hardness and adhesion strength, and the coating with 4 per cent Sm2O3 and 1 per cent La2O3 exhibits the best wear resistance and lowest friction coefficient among all the samples.
Originality/value
AT coatings mixed with different components of binary rare earth oxide of La2O3 and Sm2O3 are prepared by atmospheric plasma spraying. Binary rare earth oxide could increase the melting degree of powder and decrease porosity of AT coatings.
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Jingfu Song, Gai Zhao, Qingjun Ding and Ying Yang
The purpose of this paper is to investigate the effect of SiO2 on the tribological properties of polytetrafluoroethylene (PTFE) composites from an atomic level.
Abstract
Purpose
The purpose of this paper is to investigate the effect of SiO2 on the tribological properties of polytetrafluoroethylene (PTFE) composites from an atomic level.
Design/methodology/approach
Effect of SiO2 on the tribological properties of PTFE sliding against Cu was studied by molecular dynamics (MD) simulations to explore the inherent mechanisms from an atomic level.
Findings
SiO2 had a higher interaction energy with PTFE than copper, which contributed to an increase of interfacial temperature and velocity with severe adhesive wear on the PTFE molecules.
Originality/value
This study reveals the mechanism of SiO2 on the friction and wear behavior of PTFE by MD simulation.
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Peng Cai, Chengpeng Xu, Fei Zheng, Jingfu Song and Gai Zhao
The purpose of this paper is to investigate the effect of lanthana (La2O3) on the mechanical and tribological properties of polyimide (PI).
Abstract
Purpose
The purpose of this paper is to investigate the effect of lanthana (La2O3) on the mechanical and tribological properties of polyimide (PI).
Design/methodology/approach
The mechanical and tribological properties of PI nanocomposites filled with La2O3 were studied by molecular dynamic simulations to explore the deep mechanisms from an atomic or molecular view.
Findings
The results showed that the hardness of the PI matrix increased after La2O3 modification with a decrease of 72.4% nanoindentation depth. Besides, the friction coefficient of PI decreased by 72.2% after filling La2O3, and the shear deformation was largely reduced under the same conditions. The adsorption effect of La2O3 on the PI molecular, which reduced the atomic relative concentration, velocity, interaction with counterpart Fe layer and the temperature rise in the frictional interface, contributed to the improvement of the mechanical and tribological performance.
Originality/value
This study reveals the friction and wear mechanism of PI composites filled with rare earth oxide at the nanoscale.
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Introduction: Regulatory technology (Regtech) uses technology and innovative techniques to improve and expedite regulatory compliance procedures across various sectors, notably…
Abstract
Introduction: Regulatory technology (Regtech) uses technology and innovative techniques to improve and expedite regulatory compliance procedures across various sectors, notably the financial industry. This chapter closely examines how Regtech is being used in the financial sector.
Purpose: This study examines the adoption and implementation of Regtech solutions in the financial sector. It aims to identify the leading technologies propelling the adoption of Regtech and the benefits and challenges financial institutions face when implementing Regtech solutions for regulatory compliance.
Need of the Study: The study examines the increasing demand for effective regulatory compliance in the financial sector. Financial institutions seek novel ways to streamline compliance procedures as regulatory complexities increase. This study fulfills the need to examine the adoption of Regtech as a potential solution to enhance regulatory compliance’s efficiency and effectiveness.
Research Methodology: This chapter’s research methodology entails a comprehensive review of existing studies, and examples to collect pertinent data and insights. The current study provides an extensive and comprehensive view of the existing studies. Examining real-world examples provides practical examples and demonstrates the efficacy of Regtech in the financial sector.
Findings: The findings reveal that the adoption of Regtech is gaining momentum in the financial industry, with increasing recognition of its potential benefits. Financial institutions leverage Regtech solutions to automate compliance processes, monitor regulatory changes, and enhance risk management practices. However, technological complexities, regulatory constraints, and data security concerns pose significant hurdles to widespread adoption.
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Tingmei Wang, Gai Zhao and Qihua Wang
A series of polyurethane/bishydroxyl-terminated polydimethylsiloxane composites (PU/BTPDMS) were prepared. The effect of BTPDMS content on the tribological properties of the…
Abstract
Purpose
A series of polyurethane/bishydroxyl-terminated polydimethylsiloxane composites (PU/BTPDMS) were prepared. The effect of BTPDMS content on the tribological properties of the PU/BTPDMS composites was studied. The paper aims to discuss these issues.
Design/methodology/approach
The composites were prepared by a pre-polymer method. The properties were measured with Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA). The friction and wear characteristic of the composites were examined with MRH-3 friction-abrasion testing machine. The worn surfaces of the composites were investigated by scanning electron microscopy (SEM).
Findings
Experimental results indicated that the polyurethane modified with 7 percent BTPDMS had better tribological property than pure PU and other PU/BTPDMS composites in the present study. It exhibits lower coefficient of friction (COF) and lower wear rate value, especially under water lubrication.
Originality/value
The polyurethane was synthesized by a pre-polymer method combination with chemical modification.
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Qiongwei Ye and Baojun Ma
Internet + and Electronic Business in China is a comprehensive resource that provides insight and analysis into E-commerce in China and how it has revolutionized and continues to…
Abstract
Internet + and Electronic Business in China is a comprehensive resource that provides insight and analysis into E-commerce in China and how it has revolutionized and continues to revolutionize business and society. Split into four distinct sections, the book first lays out the theoretical foundations and fundamental concepts of E-Business before moving on to look at internet+ innovation models and their applications in different industries such as agriculture, finance and commerce. The book then provides a comprehensive analysis of E-business platforms and their applications in China before finishing with four comprehensive case studies of major E-business projects, providing readers with successful examples of implementing E-Business entrepreneurship projects.
Internet + and Electronic Business in China is a comprehensive resource that provides insights and analysis into how E-commerce has revolutionized and continues to revolutionize business and society in China.