Hot Tearing Susceptibility and Fluidity of Semi-Solid Gravity Cast Al-Cu Alloy

2006 ◽  
pp. 76-79 ◽  
Author(s):  
J. Wannasin ◽  
David Schwam ◽  
J.A. Yurko ◽  
C. Rohloff ◽  
G. Woycik
Keyword(s):  
Hot Tearing ◽  
Cu Alloy ◽  
Semi Solid ◽  
Gravity Cast ◽  
Hot Tearing Susceptibility

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.

The Effect of Y on Microstructure and Properties of Al-5wt.%Cu Based Alloy

2012 ◽  
Vol 522 ◽  
pp. 227-230 ◽  
Author(s):  
Min Li ◽  
Lan Rong Cai ◽  
Peng Xin Liu
Keyword(s):  
Fish Bone ◽  
Hot Tearing ◽  
Solidification Temperature ◽  
Mesh Structure ◽  
Microstructure And Properties ◽  
The Past ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Tearing Resistance ◽  
Hot Tearing Susceptibility

There is a great attention to the usage rate of Al-Cu alloys due to the largely use of Al-5%Cu based alloys in the aerospace industry in the past decades. The improvement of microstructure and properties of Al-5%Cu based alloy by refinement and modification. Specially, the refinement and modification of Al-Cu alloy can be achieved by addition of rare earth. In this paper, the effect of Y on the microstructure and properties of Al-5%Cu based alloy was investigated. The results show that θ (Al2Cu) phases change from mesh structure into fish-bone shape and grains are refined. Y additions promoted the end-solidification temperature and decreased the quantity of eutectic in grain boundaries, and narrowed the crystallization range and increased the hot-tearing resistance and decreased the hot-tearing susceptibility significantly.

Hot Tearing Susceptibility and Fluidity of Semi-Solid Gravity Cast Al-Cu Alloy

2006 ◽  
Vol 116-117 ◽  
pp. 76-79 ◽  
Author(s):  
J. Wannasin ◽  
David Schwam ◽  
J.A. Yurko ◽  
C. Rohloff ◽  
G. Woycik
Keyword(s):  
Liquid State ◽  
Copper Alloys ◽  
High Strength ◽  
Hot Tearing ◽  
Gravity Casting ◽  
Aluminum Copper Alloys ◽  
Semi Solid ◽  
High Superheat ◽  
Constrained Rod Casting ◽  
Hot Tearing Susceptibility

Aluminum-copper alloys offer both high strength and excellent ductility suitable for a number of automotive applications to reduce vehicle weight; however, the alloys are difficult to cast because of their tendency for hot tearing. In this work, semi-solid gravity casting of an aluminum-copper alloy, B206, was conducted in constrained rod casting molds to study the feasibility of using the process to reduce or eliminate hot tearing. To demonstrate the feasibility of gravity casting of the metal slurries, a fluidity test was also conducted. Results show that the hot tearing susceptibility of the aluminum-copper B206 alloy cast in semi-solid state is lower than those cast in liquid state with high superheat temperatures. The grain size of the semi-solid cast Al-Cu samples appears to be finer than those cast in liquid state with high superheat temperatures. In addition, the metal slurries had sufficient fluidity to fill the molds even with low gravity pressures. The results suggest that semi-solid gravity casting is a feasible process to help reduce hot tearing.

Impact of Intensification Pressure and Grain Refiner on the Hot Tearing Susceptibility of a Semi-Solid Cast Al-Zn-Mg-Cu Alloy

2019 ◽  
Vol 285 ◽  
pp. 283-289
Author(s):  
Hai Yue Zhao ◽  
Da Quan Li ◽  
Min Luo ◽  
Stephen P. Midson ◽  
Qiang Zhu
Keyword(s):  
Aluminum Alloys ◽  
Grain Refinement ◽  
Hot Tearing ◽  
Commercial Application ◽  
Cast Aluminum ◽  
Grain Refiner ◽  
Cu Alloy ◽  
Intensification Pressure ◽  
Semi Solid ◽  
The Impact

The commercial application of wrought aluminum alloys to semi-solid casting would be extremely beneficial, as wrought alloys often exhibit better strength-ductility combinations than cast aluminum alloys. Semi-solid casting typically reduces the hot tearing tendency, as it requires a globular microstructure and produces grain refinement, but hot tearing often still occurs during the semi-solid die casting of complex-shaped components produced from wrought alloys. This study examined the impact of intensification pressure and grain refinement on the hot tearing tendency of an Al-Zn-Mg-Cu alloy. Semi-solid slurries were produced using the SEED (Swirled Equilibrium Enthalpy Device) process. A specially designed constrained rod mold was used to evaluate hot tearing. Results showed the tendency for hot tearing decreased with increasing of intensification pressure. Grain refinement (with 0.06Ti) was also found to be beneficial to the elimination of hot tearing.

Tensile Properties and Hot-Tearing Tendencies of 3xxx Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 95-100 ◽  
Author(s):  
Arne Nordmark ◽  
Kjerstin Ellingsen ◽  
Anders U. Johansson ◽  
Mohammed M'Hamdi ◽  
Anne Kvithyld ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Aluminium Alloys ◽  
Solidification Path ◽  
Hot Tearing ◽  
Model Alloy ◽  
Cast House ◽  
Grain Refiner ◽  
Semi Solid ◽  
Set Up ◽  
Hot Tearing Susceptibility

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. 

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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