Influence of Cooling Rate on the Size of the Precipitates and Thermal Characteristic of Al-Si Cast Alloys

2006 ◽  
Vol 15-17 ◽  
pp. 59-64 ◽  
Author(s):  
Rafal Maniara ◽  
Leszek Adam Dobrzański ◽  
Jerry Sokolowski ◽  
Wojciech Kasprzak ◽  
Witold T. Kierkus
Keyword(s):  
Cooling Rate ◽  
Solidus Temperature ◽  
Thermal Characteristic ◽  
Solidification Process ◽  
Crystallization Curve ◽  
Dendrite Coherency Point ◽  
Cast Alloys ◽  
Main Observation ◽  
Coherency Point ◽  
Work Effect

In this work effect of cooling rate on the size of the grains, SDAS, β phases and thermal characteristic results of Al-Si cast alloys have been described. The solidification process was studied using the cooling and crystallization curve at cooling rate ranging from 0,1 °Cs-1 up to 1 °Cs-1. The main observation made from this work was that when cooling rate is increased the aluminum dendrites nucleation temperature and solid fraction at the dendrite coherency point increases, which implies that mass feeding is extended. In addition to that, it was observed that solidus temperature and size of the β phases decreases when cooling rate increases. Investigations were showed, that the thermal modification could be quantitatively assessed by analysis of the crystallization curve.

Effects of Melt Treatment on Dendrite Coherency of A357 Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 3886-3890
Author(s):  
Zhong Wei Chen ◽  
Pei Chen ◽  
Li Fan
Keyword(s):  
Thermal Analysis ◽  
Growth Rate ◽  
Cooling Rate ◽  
Solid Fraction ◽  
Dendrite Growth ◽  
A357 Alloy ◽  
Dendrite Coherency Point ◽  
Melt Treatment ◽  
Coherency Point ◽  
Dendrite Coherency

The Dendrite Coherency Point (DCP) of A357 alloy was determined after different melt treatments by double thermocouples, and the coherency solid fraction (fscoh) was calculated by thermal analysis. The results of dendrite coherency properties show that fscoh values increase with increased cooling rate for A357 alloy. For A357 alloys, fscoh values increase after grain refined and melt superheat treatment. The coherency point was found to be dependent on not only the morphology of the dendrites but also the dendrite growth rate.

Influence of Cooling Rate on the Size of the Precipitates and Thermal Characteristic of Al-Si Cast Alloys

2006 ◽  
pp. 59-64
Author(s):  
Rafal Maniara ◽  
Leszek A. Dobrzański ◽  
Jerry Sokolowski ◽  
Wojciech Kasprzak ◽  
Witold T. Kierkus
Keyword(s):  
Cooling Rate ◽  
Thermal Characteristic ◽  
Cast Alloys

Thermal Profile and Microstructure of Wrought Aluminium 7075 for Semisolid Metal Processing

2020 ◽  
Vol 17 (2) ◽  
pp. 7842-7850
Author(s):  
N. A. Razak ◽  
A. H. Ahmad ◽  
M. R. Maarof
Keyword(s):  
Cooling Rate ◽  
Solidus Temperature ◽  
Solidification Process ◽  
Graphite Crucible ◽  
Cooling Curve ◽  
Data Logger ◽  
Quick Method ◽  
Solidification Temperature ◽  
Open Atmosphere ◽  
Significant Difference

Thermal analysis (TA) is a non-damaging and quick method to check the molten metal’s condition preceding to casting. This paper aims to present the relationship between fraction solid and temperature by utilising cooling curve analysis (CCA), to acquire correct processing parameters for wrought aluminium 7075 in semisolid condition. An induction furnace was used to heat a graphite crucible containing wrought aluminium 7075 alloy up to the temperature of 750 °C. A calibrated Chromel-Alumel K-type thermocouple was placed at the centre of the crucible and was submerged to 15 mm in the melt. The solidification temperature and time were measured by Data Logger GL-220. Normal, intermediate, and high cooling rate conditions were achieved when the crucible was left in an open atmosphere, in an open atmosphere with additional minimum airflow, and in an open atmosphere with the maximum airflow, respectively. It was found that the normal cooling rate was estimated at 2.23 °C/s, the intermediate cooling rate was calculated at 2.88 °C/s while the high cooling rate was recorded at 3.20 °C/s. The increase in cooling rate conditions has a significant effect on the changes of phases during solidification process where it leads to the decreased in liquidus, eutectic and solidus temperature. The microstructure feature was found to have a significant difference with the variation of cooling rates where higher cooling rate led to smaller primary grain size.

scholarly journals Study of the Effect of Carbon on the Contraction of Hypo-Peritectic Steels during Initial Solidification by Surface Roughness

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 982 ◽  
Author(s):  
Dazhi Pu ◽  
Guanghua Wen ◽  
Dachao Fu ◽  
Ping Tang ◽  
Junli Guo
Keyword(s):  
Surface Roughness ◽  
Cooling Rate ◽  
Solidification Process ◽  
Casting Process ◽  
Continuous Casting Process ◽  
Peritectic Steel ◽  
Laser Confocal Microscope ◽  
Initial Solidification

In the continuous casting process, the shrinkage of the peritectic phase transition during the initial solidification process has an important influence on the surface quality of peritectic steel. The initial solidification process of 0.10C%, 0.14C%, and 0.16C% peritectic steels was observed in situ by a high temperature laser confocal microscope, and the contraction degree during initial solidification was characterized by surface roughness. The results showed that under the cooling rate of 20 °C/s, the surface roughness value Ra(δ/γ) of 0.10C% peritectic steel was 32 μm, the Ra(δ/γ) value of 0.14C% peritectic steel was 25 μm, and the Ra(δ/γ) value of 0.16C% peritectic steel was 17 μm. With increasing carbon content, the contraction degree of the δ→γ transformation decreased, and the value of the surface roughness Ra(δ/γ) declined. Therefore, surface roughness can characterize the contraction degree of the δ→γ transformation in the initial solidification process of peritectic steel under the condition of a large cooling rate.

Cooling rate dependence of solidification for liquid aluminium: a large-scale molecular dynamics simulation study

2016 ◽  
Vol 18 (26) ◽  
pp. 17461-17469 ◽  
Author(s):  
Z. Y. Hou ◽  
K. J. Dong ◽  
Z. A. Tian ◽  
R. S. Liu ◽  
Z. Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Cooling Rate ◽  
Simulation Study ◽  
Large Scale ◽  
Solidification Process ◽  
Molecular Dynamics Method ◽  
Dynamics Simulation ◽  
Liquid Aluminium ◽  
Dynamics Method

The effect of the cooling rate on the solidification process of liquid aluminium is studied using a large-scale molecular dynamics method.

Sign in / Sign up

Export Citation Format

Share Document