Effect of Sr modification on microstructure and thermal conductivity of hypoeutectic Al−Si alloys

2020 ◽  
Vol 30 (11) ◽  
pp. 2879-2890
Author(s):  
Jun-qi GAN ◽  
Yu-jian HUANG ◽  
Cheng WEN ◽  
Jun DU
Keyword(s):  
Thermal Conductivity ◽  
Sr Modification

scholarly journals Effect of Cooling Rate and Modification by Strontium on the Thermal Conductivity of Al-8Si Alloy

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1334
Author(s):  
Guanyi Wang ◽  
Zhiping Guan ◽  
Jinguo Wang ◽  
Mingwen Ren ◽  
Ruifang Yan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Cooling Rate ◽  
Eutectic Silicon ◽  
Critical Role ◽  
Design Strategy ◽  
Cooling Rates ◽  
Secondary Dendrite Arm Spacing ◽  
Sr Modification ◽  
The Relationship

Cooling rate plays a critical role in determining the thermal conductivity of Al-Si alloys. Although the effect of morphology and size of Si (changed by heat treatment) on its thermal conductivity has been investigated, the effect of cooling rates on thermal conductivity has not been well studied. In this study, we investigated the microstructure of an Al-8Si (with and without modification by Strontium (Sr)) alloy with cooling rates from 46.2 °C/s to 234 °C/s. It was found that the effect of cooling rate on thermal conductivity of Sr modification and Sr-free samples are opposite from each other. As a result, while the cooling rate increased from 46.2 °C/s to 234 °C/s, the calculated thermal conductivity increased from 145.3 MS/m to 151.5 MS/m for Sr-free Al-8Si alloy, and the calculated thermal conductivity was reduced from 187.5 MS/m to 176.7 MS/m for the Sr-modified Al-8Si alloy. By discussing how thermal conductivity correlates with eutectic silicon morphology and secondary dendrite arm spacing, the relationship between cooling rate and thermal conductivity were explained. This work suggests a new design strategy for improving the thermal conductivity of Al-Si hypoeutectic alloys.

HARDNESS AND THERMAL CONDUCTIVITY OF As-Se-Te CHALCOGENIDE GLASSES

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-931-C4-934 ◽  
Author(s):  
M. F. Kotkata ◽  
M.B. El-den
Keyword(s):  
Thermal Conductivity ◽  
Chalcogenide Glasses

A STUDY OF THE Pb PRECIPITATION IN NaCl FROM THERMAL CONDUCTIVITY EXPERIMENTS

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-893-C6-895
Author(s):  
M. Locatelli ◽  
R. Suchail ◽  
E. Zecchi
Keyword(s):  
Thermal Conductivity

THEORY OF THERMAL CONDUCTIVITY IN MOLECULAR CRYSTALS, APPLICATION TO ALCALI CYANIDES

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-247-C6-249 ◽  
Author(s):  
W. Bauernfeind ◽  
J. Keller ◽  
U. Schröder
Keyword(s):  
Thermal Conductivity ◽  
Molecular Crystals

The influence of the addition of ground olive stone on the thermo-mechanical behavior of compressed earth blocks

2020 ◽  
Vol 108 (2) ◽  
pp. 203
Author(s):  
Samia Djadouf ◽  
Nasser Chelouah ◽  
Abdelkader Tahakourt
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Mechanical Behavior ◽  
Agricultural Waste ◽  
Hydraulic Press ◽  
Dry Density ◽  
Olive Stone ◽  
Compressed Earth Blocks ◽  
Clay Matrix ◽  
Earth Blocks

Sustainable development and environmental challenges incite to valorize local materials such as agricultural waste. In this context, a new ecological compressed earth blocks (CEBS) with addition of ground olive stone (GOS) was proposed. The GOS is added as partial clay replacement in different proportions. The main objective of this paper is to study the effect of GOS levels on the thermal properties and mechanical behavior of CEB. We proceeded to determining the optimal water content and equivalent wet density by compaction using a hydraulic press, at a pressure of 10 MPa. The maximum compressive strength is reached at 15% of the GOS. This percentage increases the mechanical properties by 19.66%, and decreases the thermal conductivity by 37.63%. These results are due to the optimal water responsible for the consolidation and compactness of the clay matrix. The substitution up to 30% of GOS shows a decrease of compressive strength and thermal conductivity by about 38.38% and 50.64% respectively. The decrease in dry density and thermal conductivity is related to the content of GOS, which is composed of organic and porous fibers. The GOS seems promising for improving the thermo-mechanical characteristics of CEB and which can also be used as reinforcement in CEBS.

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