Microstructure, billet surface quality and tensile property of (Al2O3+Al3Zr)p/Al composites in situ synthesized with electromagnetic field

The current study investigated the effects of different strength Electromagnetic Field (EMF) exposure (250 µT, 500 µT, 1000 µT) on the commercially important decapod, edible crab (Cancer pagurus, Linnaeus, 1758). Stress related parameters were measured (l-Lactate, d-Glucose, Total Haemocyte Count (THC)) in addition to behavioural and response parameters (shelter preference and time spent resting/roaming) over 24 h periods. EMF strengths of 250 µT were found to have limited physiological and behavioural impacts. Exposure to 500 µT and 1000 µT were found to disrupt the l-Lactate and d-Glucose circadian rhythm and alter THC. Crabs showed a clear attraction to EMF exposed (500 µT and 1000 µT) shelters with a significant reduction in time spent roaming. Consequently, EMF emitted from MREDs will likely affect crabs in a strength-dependent manner thus highlighting the need for reliable in-situ measurements. This information is essential for policy making, environmental assessments, and in understanding the impacts of increased anthropogenic EMF on marine organisms.

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In-Situ Laser Polishing Additive Manufactured AlSi10Mg: Effect of Laser Polishing Strategy on Surface Morphology, Roughness and Microhardness

Materials ◽

10.3390/ma14020393 ◽

2021 ◽

Vol 14 (2) ◽

pp. 393

Author(s):

Jiantao Zhou ◽

Xu Han ◽

Hui Li ◽

Sheng Liu ◽

Shengnan Shen ◽

...

Keyword(s):

Surface Quality ◽

Molten Pool ◽

Surface Defects ◽

Polished Surface ◽

Transient Model ◽

Surface Evolution ◽

Powder Bed ◽

Laser Polishing ◽

Surface Morphologies

Laser polishing is a widely used technology to improve the surface quality of the products. However, the investigation on the physical mechanism is still lacking. In this paper, the established numerical transient model reveals the rough surface evolution mechanism during laser polishing. Mass transfer driven by Marangoni force, surface tension and gravity appears in the laser-induced molten pool so that the polished surface topography tends to be smoother. The AlSi10Mg samples fabricated by laser-based powder bed fusion were polished at different laser hatching spaces, passes and directions to gain insight into the variation of the surface morphologies, roughness and microhardness in this paper. The experimental results show that after laser polishing, the surface roughness of Ra and Sa of the upper surface can be reduced from 12.5 μm to 3.7 μm and from to 29.3 μm to 8.4 μm, respectively, due to sufficient wetting in the molten pool. The microhardness of the upper surface can be elevated from 112.3 HV to 176.9 HV under the combined influence of the grain refinement, elements distribution change and surface defects elimination. Better surface quality can be gained by decreasing the hatching space, increasing polishing pass or choosing apposite laser direction.

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Effects of low-frequency electromagnetic field on the surface quality of 7050 aluminum alloy ingots during the hot-top casting process

International Journal of Minerals Metallurgy and Materials ◽

10.1007/s12613-011-0417-x ◽

2011 ◽

Vol 18 (2) ◽

pp. 165-168 ◽

Cited By ~ 4

Author(s):

Xiang-jie Wang ◽

Jian-zhong Cui ◽

Yu-bo Zuo ◽

Zhi-hao Zhao ◽

Hai-tao Zhang

Keyword(s):

Electromagnetic Field ◽

Aluminum Alloy ◽

Surface Quality ◽

Low Frequency ◽

Casting Process ◽

Hot Top ◽

7050 Aluminum Alloy

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Microstructure and Tensile Property of Zn-Al Alloy Reinforced with Titanium Produced by Electrolysis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.1415 ◽

2009 ◽

Vol 79-82 ◽

pp. 1415-1418 ◽

Cited By ~ 6

Author(s):

Shu Qing Yan ◽

Jing Pei Xie ◽

Wen Yan Wang ◽

Ji Wen Li

Keyword(s):

Grain Size ◽

Tensile Property ◽

Heterogeneous Nucleation ◽

Titanium Content ◽

Small Dimension ◽

Al Alloy ◽

Exotic Particles ◽

Titanium Aluminum ◽

High Dispersity

In this study, some low-titanium aluminum alloys produced by electrolysis were prepared and the effect of various titanium contents on microstructure and tensile property of Zn-Al alloy was investigated. The test results showed that addition of titanium by electrolysis is an effective way to refine the grain size of Zn-Al alloy. As the titanium content is 0.04 wt%, the grain size becomes to be a minimum value and the tensile property of the alloy reaches to the maximum. Electrolysis showed that titanium atoms are to be some inherent particles in low-titanium aluminum alloy. These titanium atoms enter into the aluminum melt liquid and spread to the whole melt rapidly under stirring action of electromagnetic field of the electric current. The heterogeneous phase nuclei are high melting TiC and TiAl3 particles formed from in-situ precipitating trace C and Ti during cooling process. These in-situ precipitating heterogeneous nucleation sites with small dimension, high dispersity, cleaning interface and fine soakage with melt, have better capacity of heterogeneous nucleation than of exotic particles. It may inhibit grain growth faster and more effective in pinning dislocations, grain boundaries or sub-boundaries.

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