Effect Pouring Temperature on Casting Defect Susceptibility of Hot Tearing in Metal Alloy Al-Si

2015 ◽  
Vol 758 ◽  
pp. 95-99 ◽  
Author(s):  
Akhyar Hasan ◽  
Suyitno
Keyword(s):  
Mold Temperature ◽  
Metal Alloy ◽  
Hot Tearing ◽  
Metal Casting ◽  
Casting Temperature ◽  
Pouring Temperature ◽  
Index Analysis ◽  
Defect Susceptibility ◽  
Casting Industry ◽  
Hot Tearing Susceptibility

Hot tearing is one of metal casting defects and often found in the casting products such as cracks on the surface. Solidifaction metal causes a thermal contraction and shrinkage, when the contraction and shrinkage occurs if a metal alloy is restrained by mold design, it will effect hot tearing. Hot tearing is influenced by several factors, including the chemical composition of the alloy, the casting temperature, mold temperature, mold constraint, fast or slow solidifaction, non uniform solidifaction, and so on. This study aimed to obtain a certain temperature that cause the maximum of hot tearing defects, so it can be recommended to the metal casting industry in aluminum-silicon material to avoid the casting temperature. Three variations of the casting temperature used in this study including 710 oC, 760 oC and 810 oC. The material used in this study is an alloy of Al-1.19% Si (percent by weight). The method used is a visual method using mold CRCM (Constrain Casting Rod Modified) Horizontal used for the index analysis of HTS (Hot tearing Susceptibility). The results gotten include the hot tearing increases with the increasing of casting temperature, and it decreases with the decreasing the casting pouring. The maximum of hot tearing index is 45 HTS at 760 oC for casting temperature. Tear formed on products from smooth categories (hairline cracks) to the complete categories (broken specimen).

Slurry Preparation and Hot Tearing Susceptibility of A201 Aluminum Alloy in Rheological Die Casting

2019 ◽  
Vol 285 ◽  
pp. 311-317 ◽  
Author(s):  
Jun Zhen Gao ◽  
Qiang Zhu ◽  
Da Quan Li ◽  
Xiao Gang Hu ◽  
Min Luo ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Die Casting ◽  
Mold Temperature ◽  
Hot Tearing ◽  
Cast Aluminum Alloy ◽  
Cast Aluminum ◽  
Intensification Pressure ◽  
Semi Solid ◽  
Index Value ◽  
Hot Tearing Susceptibility

A201 alloy is the strongest cast aluminum alloy, but it is considered one of the most difficult aluminum alloys to cast due to its susceptibility to hot tearing during solidification. Semi-solid casting, which characterizes fine near-globular or non-dendritic grains and relatively narrow solidification range, is potential to reduce hot cracking tendency of alloys. In this present work, semi-solid slurries of A201 alloy were prepared using Swirled Enthalpy Equilibrium Device (SEED) technique and then injected into a self-designed high pressure hot tearing mold. The microstructures of A201 semi-solid slurries with different pouring temperatures were examined. Effects of different casting pressures on the hot tearing sensitivity of A201 have been investigated. This study finds that SEED is capable of producing satisfying A201 semi-solid slurries. Lower pouring temperatures produce A201 semi-solid slurries with finer and rounder grains as well as more uniform microstructure distribution. Increasing the intensification pressure significantly decreases the hot treating tendency of A201 alloy. When the pressure reaches to 90 MPa and the mold temperature of about 250 °C, the hot tearing susceptibility (HTS) index value is nearly zero, which means almost no surface cracks are found in the semi-solid A201 die casting parts.

Effects of Copper Content and Mold Temperature on the Hot Tearing Susceptibility of Mg-7Zn-xCu-0.6Zr Alloys

2018 ◽  
Vol 49 (6) ◽  
pp. 3444-3455 ◽  
Author(s):  
Ye Zhou ◽  
Pingli Mao ◽  
Zhi Wang ◽  
Yizhou Li ◽  
Zheng Liu ◽  
...  
Keyword(s):  
Copper Content ◽  
Mold Temperature ◽  
Hot Tearing ◽  
Hot Tearing Susceptibility

scholarly journals Effect of Returnable Material in Batch on Hot Tearing Tendency of AlSi9Cu3 Alloy

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1583
Author(s):  
Justyna Kasińska ◽  
Marek Matejka ◽  
Dana Bolibruchová ◽  
Michal Kuriš ◽  
Lukáš Širanec
Keyword(s):  
Raw Materials ◽  
Qualitative Evaluation ◽  
Hot Tearing ◽  
Material Content ◽  
Negative Effect ◽  
Increased Sensitivity ◽  
Materials Used ◽  
Shape Complexity ◽  
Tear Propagation ◽  
Hot Tearing Susceptibility

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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