Numerical Simulation of Slurry Making Process of 7075 Aluminum Alloy under Electromagnetic Field in Rheocasting Process

2019 ◽  
Vol 285 ◽  
pp. 373-379 ◽  
Author(s):  
Gan Li ◽  
Hong Xing Lu ◽  
Xiao Gang Hu ◽  
Qiang Zhu
Keyword(s):  
Aluminum Alloy ◽  
Solid Fraction ◽  
Temperature Difference ◽  
Lower Cost ◽  
Simulation Method ◽  
7075 Aluminum Alloy ◽  
Compensation Process ◽  
The Common ◽  
Semi Solid ◽  
Slurry Preparation

Rheocasting processes have several technological advantages, such as shorter processing and lower cost than thixocasting processed, while better product quality than conventional die casting. At present, the common alloys used in rheocasting processes are mainly Al-Si alloys which have limited strength. There is a strong demand for higher strength aluminum alloys in industries, for instance the 7075 aluminum alloy. However, the solid fraction of the 7075 aluminum alloy varies significantly with the temperature change in the medium solid fraction range from 0.4 to 0.6, which poses a great challenge to the slurry preparation. The enthalpy compensation process, in which the core was electromagnetic heating in the outside of the metallic crucible containing aluminum alloy melt, has been proposed to reduce the temperature difference within semi-solid slurry in this work. This study used simulation method to analyze the effects of key process parameters on the temperature difference within the 7075 aluminum alloy slurry. The simulation results indicated that semi-solid slurry with medium solid fraction may be obtained and temperature difference may be reduced to less than 4°C.

Characterizing the Effect of Processing Parameters on Temperature Distribution of 7075 Aluminum Alloy Slurry Prepared by Enthalpy Control Process

2022 ◽  
Vol 327 ◽  
pp. 263-271
Author(s):  
Gan Li ◽  
Jin Kang Peng ◽  
En Jie Dong ◽  
Juan Chen ◽  
Hong Xing Lu ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Temperature Difference ◽  
Initial Temperature ◽  
Control Process ◽  
Processing Parameters ◽  
Heating Time ◽  
7075 Aluminum Alloy ◽  
Semi Solid ◽  
7075 Alloy ◽  
Slurry Preparation

There is a strong demand for high-strength aluminum alloys such as 7075 aluminum alloy to be applied for rheocasting industry. The overriding challenge for the application of 7075 alloy is that its solid fraction is very sensitive to the variation of temperature in the range of 40% ~ 50% solid fraction, which inevitably narrows down the processing window of slurry preparation for rheocasting process. Therefore, in this work, a novel method to prepare semi-solid slurry of the 7075 alloy, so called Enthalpy Control Process (ECP), has been developed to grapple with this issue. In the method, a medium-frequency electromagnetic field was applied on the outside of slurry preparation crucible to reduce the temperature difference throughout the slurry. The effect of processing parameters, including heating power, heating time, the initial temperature of crucible and melt weight, on the temperature field of the semi-solid slurry was investigated. The results exhibited that although the all the processing parameters had a great influence on the average temperature of the slurry, heating time was the main factor affecting the maximum temperature difference of the slurry. The optimum processing parameters during ECP were found to be heating power of 7.5 KW, the initial temperature of crucible of 30 °C ~ 200 °C and melt weight of 2 kg.

Effects of Solid Fractions in a Slurry Die Casting Process on Defects of 7075 Aluminum Alloy

2015 ◽  
Vol 752-753 ◽  
pp. 7-10 ◽  
Author(s):  
Waraporn Jumpol ◽  
Jessada Wannasin ◽  
Somjai Janudom ◽  
Rungsinee Canyook ◽  
Thawatchai Plookphol ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Solid Fraction ◽  
Die Casting ◽  
Casting Process ◽  
7075 Aluminum Alloy ◽  
Die Casting Process ◽  
Semi Solid

The effects of Gas Induced Semi-Solid (GISS) in the slurry die casting process on defects of 7075 aluminum alloy were studied, different initial solid fractions with 10, 15, and 20 sec of rheocasting time were investigated. The results showed that the percentage of porosity in semi-solid die casting was smaller than in the liquid die casting. In terms of the initial solid fraction in 7075 aluminum alloy, it was found that the defects were found when the initial solid fraction was high. In addition.

Study of Surface Segregation Defect of 7075 Aluminum Alloy in Semi-Solid Squeeze Casting

2015 ◽  
Vol 752-753 ◽  
pp. 3-6 ◽  
Author(s):  
Nonanitta Umudee ◽  
Jessada Wannasin ◽  
Somjai Janudom ◽  
Rungsinee Canyook ◽  
Thawatchai Plookphol ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Solid Fraction ◽  
Surface Segregation ◽  
Squeeze Casting ◽  
7075 Aluminum Alloy ◽  
Cross Sectional ◽  
Liquid Segregation ◽  
Surface Liquid ◽  
The Cross ◽  
Semi Solid

The objective of this present research was to study the surface liquid segregation (SLS) of 7075 aluminum alloy formed by semi-solid squeeze casting together with the gas induce semi-solid technique (GISS). The rheocasting times of 3, 5, 10, and 20 seconds, were used in GISS processes. The cross sectional areas of specimens near the mold were used to measure the surface segregation. The results revealed that longer rheocasting time gave higher amount of solid fraction in the semi-solid slurry. In addition, it was found that when solid fraction increased, the surface segregation increased.

Creep of Rheocast 7075 Aluminum Alloy at 300 °C

2013 ◽  
Vol 372 ◽  
pp. 288-291 ◽  
Author(s):  
Saravut Thongkam ◽  
Sirikul Wisutmethangoon ◽  
Jessada Wannasin ◽  
Suchart Chantaramanee ◽  
Thawatchai Plookphol
Keyword(s):  
Aluminum Alloy ◽  
Creep Rate ◽  
Creep Deformation ◽  
Minimum Creep Rate ◽  
7075 Aluminum Alloy ◽  
Stress Range ◽  
Dislocation Glide ◽  
Semi Solid ◽  
Power Law Creep ◽  
Rupture Strain

Creep of rheocast 7075-T6 aluminum alloy produced by the Gas Induced Semi-Solid (GISS) process was investigated at temperature of 300 °C and stress range of 20-70 MPa and compared to that of wrought 7075-T651 aluminum alloy. The rheocast 7075-T6 alloy exhibited lower minimum creep rate and longer rupture time than the wrought 7075-T651 alloy. The total rupture strain of the rheocast alloy was shorter than that of the wrought one. According to the power law creep, the stress exponents, n of the rheocast 7075-T6 and the wrought 7075-T651 alloys were 5.9 and 7.9 respectively. Based on the determined n values, the creep deformation of both alloys was possibly controlled by the dislocation glide and climb-controlled mechanism.

Addition of Swarf to Produce a Semi-Solid Slurry during High Pressure Die-Casting of AS9U3 Aluminum Alloy

2019 ◽  
Vol 285 ◽  
pp. 271-276
Author(s):  
Hooman Hadian ◽  
M. Haddad-Sabzevar ◽  
Mohammad Mazinani
Keyword(s):  
High Pressure ◽  
Aluminum Alloy ◽  
Solid Fraction ◽  
Die Casting ◽  
Internal Cooling ◽  
High Solid ◽  
Cooling Agent ◽  
High Solid Fraction ◽  
Semi Solid ◽  
Pressure Die Casting

An internal cooling agent is used in rapid slurry forming (RSF) process to produce a high solid fraction slurry for a short period of time. In the process used in this research, the swarf which is known to be a low enthalpy material was added to the melt as the internal cooling agent. During the process, the swarf started to melt and a semi-solid slurry with a relatively high solid fraction was formed. This slurry was formed by exchanging the enthalpies between the low and high enthalpy materials. A commercial Al-Si-Cu alloy, i.e. AS9U3 Aluminum alloy, was used in this investigation. The microscopic examination showed that the Al-Si eutectic colonies start to melt during the melting process of swarf material resulting in the formation of globular Alpha-Al grains due to the multiplication of secondary dendrites arms. The fracture of dendrites arms and the subsequent spheroidization were suggested to be the origin of non-dendritic globular grains in the final microstructure. The amount of primary globular Alpha-phase was measured by the image analysis software. The results showed that during high pressure die-casting of AS9U3 Aluminum alloy using 4 mm thick samples, around 35 percent solid has been formed at the temperature of 580 oC.

K-0738 Dynamic Compressive Mechanical Properties of High Solid Fraction Aluminum Alloy in the Semi-solid State

2001 ◽  
Vol I.01.1 (0) ◽  
pp. 365-366
Author(s):  
Shusuke NAKANO ◽  
Toshiji MUKAI ◽  
Masahide KOHZU ◽  
Shigenori TANABE ◽  
Kenji HIGASHI
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Solid State ◽  
Solid Fraction ◽  
High Solid ◽  
High Solid Fraction ◽  
Semi Solid
Sign in / Sign up

Export Citation Format

Share Document