Xiaomiao Niu, Hongyao Shen, Guanhua Xu, Linchu Zhang, Jianzhong Fu and Xiaolei Deng
Mg-Al powder mixture was used to manufacture Mg-Al alloy by laser powder bed fusion (LPBF) process. This study aims to investigate the influence of initial Al content and…
Abstract
Purpose
Mg-Al powder mixture was used to manufacture Mg-Al alloy by laser powder bed fusion (LPBF) process. This study aims to investigate the influence of initial Al content and processing parameters on the formability, microstructure and consequent mechanical properties of the laser powder bed fused (LPBFed) component.
Design/methodology/approach
In this study, Al powder with different weight ratio ranged from 3 to 9 per cent was mixed with pure Mg powder, and the powder mixture was processed using different LPBF parameters. Microstructure and compressive properties of the LPBFed components were examined.
Findings
It was found that the presence of Al significantly modified the microstructure and improved the mechanical properties of the LPBFed components. Higher volume of ß-Al12Mg17 precipitates was produced at higher initial Al content and higher laser energy density. For this reason, the a-Mg was significantly refined and the compressive strength was improved. The highest yield compressive strength achieved was 279 MPa when using Mg-9 Wt. % Al mixture.
Originality/value
This work demonstrates that LPBF of Mg-Al powder mixture was a viable way to additively manufacture Mg-Al alloy. Both Al content and processing parameters can be modified to control the microstructure and mechanical properties of the LPBFed components.
Details
Keywords
Hongyao Shen, Xiaoxiang Ye, Guanhua Xu, Linchu Zhang, Jun Qian and Jianzhong Fu
During the 3D printing process, the model needs to add a support structure to ensure structural stability. Excessive support structure reduces printing efficiency and results in…
Abstract
Purpose
During the 3D printing process, the model needs to add a support structure to ensure structural stability. Excessive support structure reduces printing efficiency and results in material cost. A flexible support platform for 3 D printing has been designed. It can form an external support structure to replace the original support structure. This paper aims to study the influence of a model’s build orientation on properties when the model is printed on the platform, aiming to provide users with suitable solutions.
Design/methodology/approach
A fitness function for estimating the support structure with a support length is constructed. The particle swarm optimization (PSO) algorithm is modified and applied to find the build orientation that minimizes the support structure. However, when the model is printed on the platform, the build orientation of the minimum support structure enhances the complexity of the working path, resulting in an increase of printing time, which needs to be avoided. This paper applies a multi-objective particle swarm optimization (MOPSO) algorithm to minimize the support structure while minimizing printing time. The Pareto solution is obtained by the algorithm.
Findings
It is found that the model that has the cantilever structure can reduce more support structure after optimization on the platform, when there is surface quality requirement. When there is no limit, the modified algorithm can minimize the support structure of each model. Considering support structure and printing time, the MOPSO algorithm can easily get optimization results to guide the practical work.
Originality/value
This paper optimizes the model’s build orientation on the flexible support platform by PSO, thereby reducing material cost and improving work efficiency.
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Edgar Marcillo-Yepez, Theodoros Skevas, Kelsi Stubblefield, Chung-Ho Lin and Soheila Abachi
This study investigates the determinants of consumers’ willingness to pay (WTP) for black walnuts in the US.
Abstract
Purpose
This study investigates the determinants of consumers’ willingness to pay (WTP) for black walnuts in the US.
Design/methodology/approach
The study uses data from a 2023 survey of 916 US consumers and applies an ordered logit regression analysis to assess the determinants of WTP.
Findings
Income, consumption frequency and awareness of the health benefits of black walnuts significantly influence WTP. Moreover, 57% of individuals in our sample are willing to pay more for black walnuts than the current market price for English walnuts, the main competitor, highlighting a substantial market opportunity for black walnuts.
Originality/value
The demand for nuts, both domestically and globally, has seen a remarkable increase in recent years, largely driven by their perceived health benefits across various consumer segments. However, not all nut varieties have experienced commensurate growth, leading to a need for detailed analysis of consumer preferences, particularly for nuts with slower growth trajectories, such as those within the walnut industry. Within the walnut industry, black walnuts (Juglans nigra) stand out with unique production and commercialization dynamics – sourced predominantly from wild trees, boasting distinctive flavors and health benefits, yet facing significant challenges such as limited commercial scale, lower yields and the presence of only one processor in the US. These factors highlight the substantial market potential for black walnuts and make studying this unique crop essential for stakeholders across the nut industry who are interested in enhancing the competitiveness of the black walnut industry.