An investigation on solidification path and hot tearing tendency of Mg−2Zn−3Y−xAl alloys

2019 ◽  
Vol 50 (12) ◽  
pp. 1471-1483
Author(s):  
G. Zhang ◽  
Z. Liu ◽  
Y. Wang ◽  
S. Liu ◽  
P. Mao
2007 ◽  
Vol 539-543 ◽  
pp. 380-385 ◽  
Author(s):  
Hiromi Nagaum ◽  
Satoru Suzuki ◽  
T. Okane ◽  
T. Umeda

The effect of Fe content on hot tearing of the high-strength Al-Mg-Si alloy was systematically investigated. In this study, a thermodynamic calculation software Thermo-Calc was used to calculate the solidification path under the non-equilibrium condition, and the mechanical properties of this alloy have also been investigated during solidification using an electromagnetic induction heating tensile machine. In order to confirm the calculation results of solidification path, a quenching test also was carried out. By using the Thermo-Calc, the sequence of crystallization, crystallization temperature of formed phases and their crystallized amount were systematically investigated for each alloy in which Fe content was changed. Furthermore, by comparing the fracture surfaces of the tensile testing sample and DC billet, the temperature range of crack initiation of the alloy was examined. Comparing the temperature range of crack initiation with the crystallization phase and its crystallization order, Fe content of high-strength Al-Mg-Si alloy influenced hot tearing significantly owing to the crystallization behavior of α(AlFeMn).


2014 ◽  
Vol 794-796 ◽  
pp. 95-100 ◽  
Author(s):  
Arne Nordmark ◽  
Kjerstin Ellingsen ◽  
Anders U. Johansson ◽  
Mohammed M'Hamdi ◽  
Anne Kvithyld ◽  
...  

A set-up for tensile testing in the mushy zone allowing for studies of semi-solid mechanical behavior is available at SINTEF. A hot-tearing experimental set-up has recently been developed allowing for investigation of the hot-tearing susceptibility of industrial aluminium alloys and effects of e.g. alloying composition and grain-refiner. Load and temperature are registered during constrained solidification giving information on the mechanical behavior of the alloy during solidification. Two crack-prone alloys in the 3xxx-series (A and B) have been investigated using both techniques and the results analyzed using information about solidification path from a thermo-physical model. Alloy B is found to be mechanically weaker in the interval most susceptible to hot-tearing in agreement with cast-house experience. This study shows that the experimental techniques combined with thermo-physical modeling and characterization allow for a better understanding of the hot-tearing sensitivity of the alloys. 


2009 ◽  
Vol 46 (3) ◽  
pp. 137-152 ◽  
Author(s):  
Mile Djurdjevic ◽  
Glenn Byczynski ◽  
Carola Schechowiak ◽  
Hagen Stieler ◽  
Jelena Pavlovic

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1583
Author(s):  
Justyna Kasińska ◽  
Marek Matejka ◽  
Dana Bolibruchová ◽  
Michal Kuriš ◽  
Lukáš Širanec

The main reason for the use of returnable material, or recycled alloys, is a cost reduction while maintaining the final properties of the casting. The casting resulting quality is directly related to the correct ratio of commercial grade alloy and alloy made by remelting the returnable material in the batch. The casting quality is also affected by the purity of the secondary raw materials used, the shape complexity and the use of the casting itself. The presented article focuses on the effect of increasing the returnable material content in the batch on the hot tearing susceptibility of AlSi9Cu3 alloy. Hot tears are a complex phenomenon that combines metallurgical and thermo-mechanical interactions of the cast metal. Hot tearing susceptibility was evaluated on the basis of quantitative (HTS — hot tearing susceptibility index) and qualitative evaluation. The negative effect of returnable material in the batch was already manifested at a 20% content in the batch. The critical proportion of the returnable alloy in the batch can be stated as 50%. The alloy with a 50% returnable material content manifested insufficient results of the HTS index and qualitative evaluation, which means increased sensitivity to tearing. The negative effect of returnable material and the increased sensitivity were also confirmed in the evaluation of the fracture surface and hot tear profile. The microstructure of alloys with 50% and higher proportion of returnable material was characterized by a higher amount of iron phases (mainly Al5FeSi), whose sharp ends acted as critical regions of hot tearing and subsequent hot tear propagation, which had a major impact on the increase in hot tearing susceptibility.


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