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The goal of this study is to investigate the relationships among brand attachment, online source credibility, and severity of negative online information on perceived negative change in brand evaluation and perceived brand risk.

A 2×2×2 experiment was conducted to explore the effects of brand attachment (low or high), online source credibility (low or high), and online information severity (low or high) on perceived negative change in brand evaluation and perceived brand risk.

The results showed that the severity of negative online information affects perceived negative change in brand evaluation and perceived brand risk significantly. However brand attachment can reduce the effects of negative online information on perceived negative change in brand evaluation and perceived brand risk significantly. The results also showed that the effect of the severity of negative online information on perceived negative change in brand evaluation and perceived brand risk is moderated by online source credibility.

In addition to the main effects in the proposed research model, it is the first study to explore the moderating effects of brand attachment and online source credibility on the relationship between negative online information and perceived negative change in brand evaluation and perceived brand risk.

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.

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.

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.

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.