Yu-Xiang Wang, Chia-Hung Hung, Hans Pommerenke, Sung-Heng Wu and Tsai-Yun Liu
This paper aims to present the fabrication of 6061 aluminum alloy (AA6061) using a promising laser additive manufacturing process, called the laser-foil-printing (LFP) process…
Abstract
Purpose
This paper aims to present the fabrication of 6061 aluminum alloy (AA6061) using a promising laser additive manufacturing process, called the laser-foil-printing (LFP) process. The process window of AA6061 in LFP was established to optimize process parameters for the fabrication of high strength, dense and crack-free parts even though AA6061 is challenging for laser additive manufacturing processes due to hot-cracking issues.
Design/methodology/approach
The multilayers AA6061 parts were fabricated by LFP to characterize for cracks and porosity. Mechanical properties of the LFP-fabricated AA6061 parts were tested using Vicker’s microhardness and tensile testes. The electron backscattered diffraction (EBSD) technique was used to reveal the grain structure and preferred orientation of AA6061 parts.
Findings
The crack-free AA6061 parts with a high relative density of 99.8% were successfully fabricated using the optimal process parameters in LFP. The LFP-fabricated parts exhibited exceptional tensile strength and comparable ductility compared to AA6061 samples fabricated by conventional laser powder bed fusion (LPBF) processes. The EBSD result shows the formation of cracks was correlated with the cooling rate of the melt pool as cracks tended to develop within finer grain structures, which were formed in a shorter solidification time and higher cooling rate.
Originality/value
This study presents the pioneering achievement of fabricating crack-free AA6061 parts using LFP without the necessity of preheating the substrate or mixing nanoparticles into the melt pool during the laser melting. The study includes a comprehensive examination of both the mechanical properties and grain structures, with comparisons made to parts produced through the traditional LPBF method.
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Keywords
Usman Tariq, Ranjit Joy, Sung-Heng Wu, Muhammad Arif Mahmood, Asad Waqar Malik and Frank Liou
This study aims to discuss the state-of-the-art digital factory (DF) development combining digital twins (DTs), sensing devices, laser additive manufacturing (LAM) and subtractive…
Abstract
Purpose
This study aims to discuss the state-of-the-art digital factory (DF) development combining digital twins (DTs), sensing devices, laser additive manufacturing (LAM) and subtractive manufacturing (SM) processes. The current shortcomings and outlook of the DF also have been highlighted. A DF is a state-of-the-art manufacturing facility that uses innovative technologies, including automation, artificial intelligence (AI), the Internet of Things, additive manufacturing (AM), SM, hybrid manufacturing (HM), sensors for real-time feedback and control, and a DT, to streamline and improve manufacturing operations.
Design/methodology/approach
This study presents a novel perspective on DF development using laser-based AM, SM, sensors and DTs. Recent developments in laser-based AM, SM, sensors and DTs have been compiled. This study has been developed using systematic reviews and meta-analyses (PRISMA) guidelines, discussing literature on the DTs for laser-based AM, particularly laser powder bed fusion and direct energy deposition, in-situ monitoring and control equipment, SM and HM. The principal goal of this study is to highlight the aspects of DF and its development using existing techniques.
Findings
A comprehensive literature review finds a substantial lack of complete techniques that incorporate cyber-physical systems, advanced data analytics, AI, standardized interoperability, human–machine cooperation and scalable adaptability. The suggested DF effectively fills this void by integrating cyber-physical system components, including DT, AM, SM and sensors into the manufacturing process. Using sophisticated data analytics and AI algorithms, the DF facilitates real-time data analysis, predictive maintenance, quality control and optimal resource allocation. In addition, the suggested DF ensures interoperability between diverse devices and systems by emphasizing standardized communication protocols and interfaces. The modular and adaptable architecture of the DF enables scalability and adaptation, allowing for rapid reaction to market conditions.
Originality/value
Based on the need of DF, this review presents a comprehensive approach to DF development using DTs, sensing devices, LAM and SM processes and provides current progress in this domain.
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Tze-Yin Lim, Choi-Meng Leong, Lucas Tee-Kiat Lim, Bibiana Chiu-Yiong Lim, Rodney Thiam-Hock Lim and Kiat-Sing Heng
This study aims to investigate the factors affecting the intention to visit community-based homestays among young adults in a developing country during the pandemic by…
Abstract
Purpose
This study aims to investigate the factors affecting the intention to visit community-based homestays among young adults in a developing country during the pandemic by incorporating the mediation effect of perceived values and moderation effects of safety and health concerns.
Design/methodology/approach
Data from young adults were gathered via a self-administered questionnaire, and 268 sets of surveys were analysed using partial least squares structural equation modelling.
Findings
The perceived value of community-based homestays among young adults is positively affected by relaxation, learning and entertainment. Perceived value also mediates the relationship between each of the three said motivational push factors and the intention to visit a community-based homestay. The relationship between perceived value and intention to visit community-based homestays among young adults is unaffected by safety and health concerns.
Research limitations/implications
The analysis reveals that relaxation, learning and entertainment are key drivers of intentions to visit rural community-based homestays and that perceived value mediates links between them.
Practical implications
This study benefits the tourism authorities and marketers by enabling them to promote community-based homestays in the country among the young adult market.
Originality/value
This study contributes to the literature by using the motivation theory and model of goal-oriented behaviour to investigate the moderating effects of health and safety concerns on young adults visiting intention. Young adults’ perceived value was also examined to study its mediating effects on visiting intention.