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1 – 3 of 3Swee Leong Sing, Wai Yee Yeong, Florencia Edith Wiria, Bee Yen Tay, Ziqiang Zhao, Lin Zhao, Zhiling Tian and Shoufeng Yang
This paper aims to provide a review on the process of additive manufacturing of ceramic materials, focusing on partial and full melting of ceramic powder by a high-energy laser…
Abstract
Purpose
This paper aims to provide a review on the process of additive manufacturing of ceramic materials, focusing on partial and full melting of ceramic powder by a high-energy laser beam without the use of binders.
Design/methodology/approach
Selective laser sintering or melting (SLS/SLM) techniques are first introduced, followed by analysis of results from silica (SiO2), zirconia (ZrO2) and ceramic-reinforced metal matrix composites processed by direct laser sintering and melting.
Findings
At the current state of technology, it is still a challenge to fabricate dense ceramic components directly using SLS/SLM. Critical challenges encountered during direct laser melting of ceramic will be discussed, including deposition of ceramic powder layer, interaction between laser and powder particles, dynamic melting and consolidation mechanism of the process and the presence of residual stresses in ceramics processed via SLS/SLM.
Originality/value
Despite the challenges, SLS/SLM still has the potential in fabrication of ceramics. Additional research is needed to understand and establish the optimal interaction between the laser beam and ceramic powder bed for full density part fabrication. Looking into the future, other melting-based techniques for ceramic and composites are presented, along with their potential applications.
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Keywords
Tiebing Shi, Robert Guang Tian, Cindy Zhiling Tu and Chi Lo Lim
This study aims to explore how two affective factors (i.e. brand attachment and consumer affinity) influence host country consumers' responses to an international brand alliance…
Abstract
Purpose
This study aims to explore how two affective factors (i.e. brand attachment and consumer affinity) influence host country consumers' responses to an international brand alliance (IBA).
Design/methodology/approach
A two (brand attachment: high vs low) × two (consumer affinity: high vs low) factorial experiment was conducted with 336 US university students. The partial least squares structural equation modeling (PLS-SEM) method was used to test the conceptual model.
Findings
(1) Pre-attachment to the host brand and consumer affinity for the country-of-origin (COO) of the foreign partner brand positively influence attitudes toward the IBA. (2) Attitudes toward the IBA positively influence post-attachment to the host brand, intention to buy the IBA product and willingness to recommend the IBA product. (3) Pre-attachment to the host brand positively influences post-attachment to the host brand.
Originality/value
This study extends the literature on factors influencing attitudes toward IBAs by finding the significant influences of pre-attachment to the host brand and consumer affinity for the COO of the foreign partner brand on host country consumers' responses to IBAs.
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– An engine component made from 1Cr18Ni9Ti alloy to be used underwater was the subject of the present research investigation.
Abstract
Purpose
An engine component made from 1Cr18Ni9Ti alloy to be used underwater was the subject of the present research investigation.
Design/methodology/approach
A stereomicroscope, a metallurgical microscope, a microhardness tester and an electron energy dispersion spectroscope were used to observe cross-sections of the alloy’s microstructure at different locations, as well as its overall corrosion behavior.
Findings
The corrosion of the 1Cr18Ni9Ti alloy, attributed to welding, cold processing and plastic deformation processes, was investigated together with an analysis of the chemical composition of the corrosion products and microsclerometry of the cross-sections. It was revealed that defects such as shrinkage cavities and porosity, often were observed to occur in the welding fusion zone. During cold processing treatments, work hardening was induced in the surface layer. Corrosion products consisted of oxides, chlorides and sulfides, with oxides as the dominant component. The high chromium content of d-ferrite had resulted in chromium depletion in nearby phase boundaries, which had led to oxidation and corrosion at these boundaries. As the electrode potential of d-ferrite is different to that of austenite, it is possible for a galvanic couple to develop between the two phases, leading to differential rates of corrosion attack.
Originality/value
Methods are proposed to improve corrosion resistance by improving the quality of the surface overlaying processes and by adopting special surface treatment techniques.
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