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1 – 4 of 4Xiangou Zhang, Yuexing Wang, Xiangyu Sun, Zejia Deng, Yingdong Pu, Ping Zhang, Zhiyong Huang and Quanfeng Zhou
Au stud bump bonding technology is an effective means to realize heterogeneous integration of commercial chips in the 2.5D electronic packaging. The purpose of this paper is to…
Abstract
Purpose
Au stud bump bonding technology is an effective means to realize heterogeneous integration of commercial chips in the 2.5D electronic packaging. The purpose of this paper is to study the long-term reliability of the Au stud bump treated by four different high temperature storage times (200°C for 0, 100, 200 and 300 h).
Design/methodology/approach
The bonding strength and the fracture behavior are investigated by chip shear test. The experiment is further studied by microstructural characterization approaches such as scanning electron microscope, energy dispersive spectrometer and so on.
Findings
It is recognized that there were mainly three typical fracture models during the chip shear test among all the Au stud bump samples treated by high temperature storage. For solder bump before aging, the fracture occurred at the interface between the Cu pad and the Au stud bump. As the aging time increased, the fracture mainly occurred inside the Au stud bump at 200°C for 100 and 200 h. When aging time increased to 300 h, it is found that the fracture transferred to the interface between the Au stud bump and the Al Pad.
Originality/value
In addition, the bonding strength also changed with the high temperature storage time increasing. The bonding strength does not change linearly with the high temperature storage time increasing but decreases first and then increases. The investigation shows that the formation of the intermetallic compounds because of the reaction between the Au and Al atoms plays a key role on the bonding strength and fracture behavior variation.
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Hailong Du, Zengyao Chen, Xiyan Wang, Yongliang Li, Renshu Yang, Zhiyong Liu, Aibing Jin and Xiaogang Li
The purpose of this paper is to develop new types of anchor bolt materials by adding corrosion-resistant elements for alloying and microstructure regulation.
Abstract
Purpose
The purpose of this paper is to develop new types of anchor bolt materials by adding corrosion-resistant elements for alloying and microstructure regulation.
Design/methodology/approach
Three new anchor bolt materials were designed around the 1Ni system. The stress corrosion cracking resistance of the new materials was characterized by microstructure observation, electrochemical testing and slow strain rate tensile testing.
Findings
The strength of the new anchor bolt materials has been improved, and the stress corrosion sensitivity has been reduced. The addition of Nb makes the material exhibit excellent stress corrosion resistance under –1,200 mV conditions, but the expected results were not achieved when Nb and Sb were coupled.
Originality/value
The new anchor bolt materials designed around 1Ni have excellent stress corrosion resistance, which is the development direction of future materials. Nb allows the material to retain its ability to extend in hydrogen-evolution environments.
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Shi Chen, Zhiyong Han, Qiang Zeng, Bing Wang, Liming Wang, Liuyang Guo and Yimin Shao
Hydro-viscous drive (HVD) clutches are widely used in equipment requiring soft start, such as fans and pumps, to transmit torque and adjust speed by changing the gap distance…
Abstract
Purpose
Hydro-viscous drive (HVD) clutches are widely used in equipment requiring soft start, such as fans and pumps, to transmit torque and adjust speed by changing the gap distance between friction pairs. This paper aims to propose a novel two-parameter evaluation method for HVD during the mixed lubrication stage. The objective is to develop an effective model that establishes the relationship between these parameters and the actual surface topography.
Design/methodology/approach
In the presented methods, the fractal features of the real manufacturing surface are calculated based on the power spectrum function by the ultra-depth three-dimensional microscope. After that, the hybrid friction model of the friction plate is established based on mixed elasto-hydrodynamic lubrication theory, boundary friction model and fractal theory. Then the torque and load bearing characteristics of the clutch are obtained, and the influences of the surface fractal features are investigated and discussed. Finally, the Weierstrass–Mandelbrot function is adopted for the surface topography characterization and evaluation.
Findings
The results indicate that the proposed method exhibits good accuracy, while the speed difference between the friction pair exceeds 2,500 rpm. It is concluded that this paper proposed a way to evaluate the torque and loading capacity of HVD considering the real manufacturing surface topography and is helpful for surface optimization.
Originality/value
The originality and value of this study lie in its development of a novel torque and load bearing capacity evaluation method for HVD in mixed lubrication stage, considering manufacturing surface topography and describing the real manufacturing surface.
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Zhiyong Li, Mingmin Huo, Tingting Huo and Hemin Luo
This study aims to review the diversified existing literature on digital tourism from 2002 to 2023 using bibliometric analysis to present a holistic review of the current…
Abstract
Purpose
This study aims to review the diversified existing literature on digital tourism from 2002 to 2023 using bibliometric analysis to present a holistic review of the current scientific structure of digital tourism and sets the future research agenda.
Design/methodology/approach
A detailed search of 646 SSCI articles collected from the Web of Science Core Collection (WOSCC) database was analysed through CiteSpace.
Findings
The findings indicate that developed countries are at the core of the co-authorship network, although developing countries represented by China increasingly contribute valued research findings. The conceptual structure of digital tourism mainly evolves from exploration (2002–2006), and acceleration (2007–2014), to diversification (2015-2023), with the most recent focus on consumer-oriented value creation and potential technological risks. Three well-established thematic groups have been identified, namely, technological innovation and application, destination digital management and consumer value creation. Constructive insights for future research are also offered, including digital scenarios, digital production and digital governance.
Practical implications
The research helps scholars and practitioners grasp the current issues and needs of digital tourism and provides a guide for policymakers in the tourism industry who seek to intelligently improve tourism performance.
Originality/value
This study thoroughly evaluates 22 years of digital tourism literature through bibliometric analysis. It creates a framework for understanding how digital tourism is theorised and developed and indicates future research directions.
目的
本篇论文旨在使用文献计量法梳理2002–2023年间的数字旅游研究, 提出整体知识架构和未来研究议程。
设计/方法/途径
本篇论文运用CiteSpace对从Web of Science Core Collection (WOSCC)数据库中检索得到的646篇SSCI文献进行分析。
发现
(1)发达国家处于作者合作网络的核心位置, 而以中国为代表的发展中国家持续产出有影响力的研究成果; (2)数字旅游的概念结构演化经历三个阶段:探索期(2002–2006年)、加速期(2007–2014年)以及多样化(2015–2023年), 其中新兴研究热点为顾客导向的价值创造和潜在技术风险; (3)数字旅游研究主题分为三个类型, 即技术创新和应用、目的地数字化管理和顾客价值创造; (4)未来研究方向包括数字情境、数字生产和数字监管。
实践意义
本篇论文有助于学界和业界人士掌握数字旅游产业的现状和需要, 并为政策制定者提供数智化提升旅游业绩效的参考。
独创性
本篇论文通过文献计量法系统回顾了22年间的数字旅游文献, 并进一步提出包含数字旅游演化和未来研究前沿的理论框架。
Finalidad
Este estudio tiene como objetivo revisar la diversa literatura existente sobre turismo digital desde 2002 hasta 2023 utilizando un método de análisis bibliométrico para revisar de manera integral la estructura científica actual del turismo digital y desarrollar una agenda de investigación futura.
Diseño/metodología/enfoque
A partir de una búsqueda detallada de 646 artículos del SSCI recogidos en la colección principal de Web of Science (WOSCC), se analizó la base de datos mediante CiteSpace.
Resultados
Los resultados muestran que los países desarrollados constituyen el núcleo de la red de coautoría, mientras que los países en desarrollo representados por China también contribuyen cada vez más con valiosos resultados de investigación. La estructura conceptual del turismo digital evoluciona principalmente desde la exploración (2002–2006), y la aceleración (2007–2014), hasta la diversificación (2015–2023), centrándose más recientemente en la creación de valor orientada al consumidor y en los posibles riesgos tecnológicos. Se han identificado tres grupos temáticos bien establecidos, a saber, innovación y aplicación tecnológicas, gestión digital de destinos y creación de valor para el consumidor. También se ofrecen ideas constructivas para futuras investigaciones, como los escenarios digitales, la producción y la gobernanza digitales.
Limitaciones/implicaciones practices
La investigación ayuda a estudiosos y profesionales a comprender los problemas y necesidades actuales del turismo digital y proporciona una guía para los responsables políticos del sector turístico que pretenden mejorar de forma inteligente los resultados del turismo.
Originalidad/valor
Este estudio evalúa exhaustivamente 22 años de literatura sobre turismo digital mediante un análisis bibliométrico. Crea un marco para comprender cómo se teoriza y desarrolla el turismo digital e indica futuras direcciones de investigación.
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