Effects of Specific Pressure and the Dual Refiner on Microstructure of the Squeeze-Cast 2024 Aluminum Alloy Drive Hollow Shaft

2014 ◽  
Vol 487 ◽  
pp. 153-156
Author(s):  
Cai He Fan ◽  
Yue Bing Zhu
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Mass Fraction ◽  
Squeeze Casting ◽  
Specific Pressure ◽  
Lower Mass ◽  
2024 Aluminum Alloy ◽  
Hollow Shaft ◽  
Squeeze Cast ◽  
Average Grain Size

Effects of specific pressure and the dual refiner of Al-5Ti-1B and Al-10RE on microstructure of the hollow 2024 aluminum alloy drive shaft prepared by squeeze casting in express locomotive were investigated in this paper. With the increasing specific pressure, the ɑ-A1 primary grains became rounder and smaller. With the specific pressure up to 120 MPa, the average grain size of the ɑ-A1 primary grains and the average equivalent roundness were 38 μm and 0.75 respectively. When the dual refiner was adopted, the average grain size of the alloy decreased obviously with a lower mass fraction of A1-5Ti-1B and a higher mass fraction of Al-10RE. However, no obvious change was detected in the average equivalent roundness. The roundness value ranged from 0.62 to 0.72. With the dual refiner of 1wt% Al-5Ti-1B and 3wt% Al-10RE, the average grain size of the alloy and the average equivalent roundness were 26 μm and 0.71 respectively.

Effects of Casting Temperature and RE Refiner on Microstructure of the Squeeze-Cast Al-Zn-Mg-Cu Alloy Drive Hollow Shaft

2013 ◽  
Vol 779-780 ◽  
pp. 78-83 ◽  
Author(s):  
Cai He Fan ◽  
Yue Bing Zhu ◽  
Na Yang
Keyword(s):  
Grain Size ◽  
Temperature Increase ◽  
Squeeze Casting ◽  
Drive Shaft ◽  
Casting Temperature ◽  
Hollow Shaft ◽  
Squeeze Cast ◽  
Cu Alloy ◽  
Average Grain Size ◽  
Variation Range

Effects of casting temperature and RE refiner on microstructure of the hollow Al-Zn-Mg-Cu alloy drive shaft prepared by squeeze casting ( in express locomotive) were investigated in this paper. As the casting temperature increase from 720°C up to 780°C, the average grain size of the α-A1 primary grains increased from 32μm up to 51μm, and the average equivalent roundness changed irregularly. Meanwhile the variation range was not big and the roundness value ranged from 0.63 to 0.72. With the casting temperature up to 780°C, the average equivalent roundness was 0.71. When the refiner was adopted, the average grain size of the alloy decreased obviously. However, no obvious change was detected in the average equivalent roundness, which ranged from 0.73 to 0.78. With the refiner of 3wt% Al-10RE, the average grain size of the alloy and the average equivalent roundness were 35μm and 0.77, respectively.

scholarly journals A Physical-Based Plane Stress Constitutive Model for High Strength AA7075 under Hot Forming Conditions

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 314
Author(s):  
Fulong Chen ◽  
Haitao Qu ◽  
Wei Wu ◽  
Jing-Hua Zheng ◽  
Shuguang Qu ◽  
...  
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Plane Stress ◽  
Metal Forming ◽  
Electron Backscatter Diffraction ◽  
High Strength ◽  
Material Model ◽  
Hot Forming ◽  
Industrial Processing ◽  
Average Grain Size

Physicallybased constitutive equations are increasingly used for finite element simulations of metal forming processes due to the robust capability of modelling of underlying microstructure evolutions. However, one of thelimitations of current models is the lack of practical validation using real microstructure data due to the difficulties in achieving statistically meaningful data at a sufficiently large microstructure scale. Particularly, dislocation density and grain size governing the hardening in sheet deformation are of vital importance and need to be precisely quantified. In this paper, a set of dislocation mechanics-based plane stress material model is constructed for hot forming aluminum alloy. This material model is applied to high strength 7075 aluminum alloy for the prediction of the flow behaviorsconditioned at 300–400 °C with various strain rates. Additionally, an electron backscatter diffraction (EBSD) technique was applied to examine the average grain size and geometrical necessary dislocation (GND) density evolutions, enabling both macro- and micro- characteristics to be successfully predicted. In addition, to simulate the experienced plane stress states in sheet metal forming, the calibrated model is further extended to a plane stress stateto accuratelypredict the forming limits under hot conditions.The comprehensively calibrated material model could be used for guidinga better selection of industrial processing parameters and designing process windows, taking into account both the formed shape as well as post formed microstructure and, hence, properties.

scholarly journals Experimental Investigation and Optimization of the Semisolid Multicavity Squeeze Casting Process for Wrought Aluminum Alloy Scroll

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5278
Author(s):  
Yi Guo ◽  
Yongfei Wang ◽  
Shengdun Zhao
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Process Parameters ◽  
Squeeze Casting ◽  
Shrinkage Porosity ◽  
Optimal Process ◽  
Squeeze Pressure ◽  
Wrought Aluminum

Scroll compressors are popularly applied in air-conditioning systems. The conventional fabrication process causes gas and shrinkage porosity in the scroll. In this paper, the electromagnetic stirring (EMS)-based semisolid multicavity squeeze casting (SMSC) process is proposed for effectively manufacturing wrought aluminum alloy scrolls. Insulation temperature, squeeze pressure, and the treatment of the micromorphology and mechanical properties of the scroll were investigated experimentally. It was found that reducing the insulation temperature can decrease the grain size, increase the shape factor, and improve mechanical properties. The minimum grain size was found as 111 ± 3 μm at the insulation temperature of 595 °C. The maximum tensile strength, yield strength, and hardness were observed as 386 ± 8 MPa, 228 ± 5 MPa, and 117 ± 5 HV, respectively, at the squeeze pressure of 100 MPa. The tensile strength and hardness of the scroll could be improved, and the elongation was reduced by the T6 heat treatment. The optimal process parameters are recommended at an insulation temperature in the range of 595–600 °C and a squeeze pressure of 100 MPa. Under the optimal process parameters, scroll casting was completely filled, and there was no obvious shrinkage defect observed inside. Its microstructure is composed of fine and spherical grains.

scholarly journals Aging Behavior of Aluminum Alloy 6082 Subjected to Friction Stir Processing

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 337 ◽  
Author(s):  
Khaled Al-Fadhalah ◽  
Fahad Asi
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Aging Time ◽  
Friction Stir Processing ◽  
Aging Temperature ◽  
Friction Stir ◽  
Average Grain Size ◽  
Different Temperatures ◽  
Equiaxed Grains ◽  
Electron Back Scattered Diffraction

The present work examined the effect of artificial aging on the microstructure, texture, and hardness homogeneity in aluminum alloy AA6082 subjected to friction stir processing (FSP). Aging was applied to FSP samples at three different temperatures (150 °C, 175 °C, and 200 °C) for a period of 1 h, 6 h, and 12 h. Microstructure analysis using optical Microscopy (OM) and Electron Back-Scattered Diffraction (EBSD) indicated that FSP produced fine equiaxed grains, with an average grain size of 6.5 μm, in the stir zone (SZ) due to dynamic recrystallization. Aging was shown to result in additional grain refinement in the SZ due to the occurrence of recovery and recrystallization with either increasing aging temperature and/or aging time. An optimum average grain size of 3–4 μm was obtained in the SZ by applying aging at 175 °C. This was accompanied by an increase in the fraction of high-angle grain boundaries. FSP provided a simple shear texture with a major component of B fiber. Increasing aging temperature and/or time resulted in the formation of recrystallization texture of a Cube orientation. In addition, Vickers microhardness was evaluated for the FSP sample, indicating a softening in the SZ due to the dissolution of the hardening precipitates. Compared to other aging temperatures, aging at 175 °C resulted in maximum hardness recovery (90 Hv) to the initial value of base metal (92.5 Hv). The hardness recovery is most likely attributed to the uniform distribution of fine hardening precipitates in the SZ when increasing the aging time to 12 h.

scholarly journals Synergistic Effect of La and TiB2 Particles on Grain Refinement in Aluminum Alloy

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 600
Author(s):  
Lili Zhang ◽  
Yan Song ◽  
Linjie Yang ◽  
Jiuzhou Zhao ◽  
Jie He ◽  
...  
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Synergistic Effect ◽  
Grain Refinement ◽  
Grain Refining ◽  
Average Grain Size ◽  
Calculation Results ◽  
La Addition ◽  
Tib2 Particles ◽  
Addition Level

Synergistic effect of TiB2 (in form of Al-5Ti-1B) and La on grain refining results in Al-2Cu alloy was investigated. α-Al grains are significantly refined by Al-5Ti-1B. When trace La is added to the melt, further refinement is exhibited. Average grain size and nucleation undercooling of α-Al reduce first and then almost remain unchanged with La addition. Satisfactory grain refining result achieves when La addition level reaches 600 ppm. When more than 600 ppm La is added to the melt, La-rich particles form and the effect of solute La left in matrix on the microstructure almost no longer changes. Theoretical calculation results demonstrate that solute La segregates to Al melt/TiB2 particles interface along with Ti and Cu prior to α-Al nucleation and the synergistic effect of La and TiB2 particles on grain refinement mainly attributes to the enhancement in the potency of TiB2 particles to heterogeneously nucleate α-Al by trace La addition.

scholarly journals Effect of Sc on the Hot Cracking Properties of 7xxx Aluminum Alloy and the Microstructure of Squeeze Castings

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6881
Author(s):  
Yongtao Xu ◽  
Zhifeng Zhang ◽  
Zhihua Gao ◽  
Yuelong Bai ◽  
Purui Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Aluminum Alloy ◽  
Performance Test ◽  
Casting Process ◽  
Hot Cracking ◽  
Hot Tearing ◽  
Average Grain Size ◽  
Cylindrical Parts ◽  
Series Aluminum Alloy

In this paper, the effect of adding the refiner Sc to the high Zn/Mg ratio 7xxx series aluminum alloy melt on the hot tearing performance, microstructure, and mechanical properties of the alloy is studied. The hot tearing performance test (CRC) method is used to evaluate the hot tearing performance of the alloy. The squeeze casting process was used to form solid cylindrical parts to analyze the structure and properties of the alloy. This study shows that the hot cracking sensitivity of the alloy after the addition of the refiner Sc is significantly reduced. The ingot grain size is significantly reduced, and the average grain size is reduced from about 86 μm to about 53 μm. While the mechanical properties are significantly improved, and the tensile strength reduced from 552 MPa is increased to 571 MPa, and the elongation rate is increased from 11% to 14%.

Study on Microstructures and Components Uniformity of 7050 Aluminum Alloy with Annulus Electromagnetic Stirring Casting

2016 ◽  
Vol 850 ◽  
pp. 716-721
Author(s):  
Ya Bao Wang ◽  
Zhen Lin Zhang ◽  
Bao Li ◽  
Zhi Hua Gao ◽  
Zhi Feng Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Shape Factor ◽  
Grain Shape ◽  
Chemical Component ◽  
Electromagnetic Stirring ◽  
High Chemical ◽  
Globular Structure ◽  
7050 Aluminum Alloy ◽  
Average Grain Size

7050aluminum alloy billets processed by semi-continuous casting were studied using conventional casting (N-EMS), conventional electromagnetic stirring casting (EMS) and annulus electromagnetic stirring casting (AEMS), respectively. Adopting the method of mathematical statistics, Zn, Mg, Cu chemical component uniformity and the microstructure of 7050 aluminum alloy billets were analyzed. The results showed that the high chemical component uniformity of the AEMS billets were obtained compared with N-EMS and EMS. The Zn, Mg, Cu element component variance was reduced 26% compared with EMS. And the A-EMS process exhibited superior grain refinement and remarkable structure homogeneity, which mainly consisted of rosaceous and nearly globular structure. The average grain size for AEMS sample was 42μm, and the grain shape factor was about 0.68.

scholarly journals Establishment of Prediction Model of Microstructure and Properties of 3003 Aluminum Alloy during Hot Deformation

2019 ◽  
Vol 25 (4) ◽  
pp. 369-375 ◽  
Author(s):  
Guiqing CHEN ◽  
Gaosheng FU ◽  
Tianyun WEI ◽  
Chaozeng CHENG ◽  
Huosheng WANG ◽  
...  
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Steady State ◽  
Flow Stress ◽  
Prediction Model ◽  
Hot Deformation ◽  
Steady State Flow ◽  
State Flow ◽  
Average Grain Size ◽  
The Relationship

The 3003 aluminum alloy was deformed by isothermal compression in the range of deformation temperature 300 – 500 ℃ at strain rate 0.0l – 10.0 s-1 with Gleeble-1500 thermal simulator. A constitutive equation is established from the flow stress of the hot deformation. It is found that the average grain size of the 3003 aluminum alloy increases with the decrease of Zener-Hollomon (Z) value, and there is a linear correlation between them. The prediction model of the steady-state flow stress and the average grain size is established. The steady-state flow stress increases with the decrease of the average grain size. The microhardness of the 3003 aluminum alloy has a positive linear relationship with lnZ, and the relationship between the microhardness and the grain size meets the Hall-Petch equation, which can provide a reference for the microstructure control and rolling equipment selection of the 3003 aluminum alloy under hot deformation conditions.

Effect of Rolling Direction on the Microstructure and Mechanical Properties of Accumulative Roll Bonding (ARB) Processed Commercially Pure 1050 Aluminum Alloy

2006 ◽  
Vol 503-504 ◽  
pp. 681-686 ◽  
Author(s):  
Yong Suk Kim ◽  
Suk Ha Kang ◽  
Dong Hyuk Shin
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Tensile Elongation ◽  
Rolling Direction ◽  
Rolled Plate ◽  
Al Alloy ◽  
Cycle Number ◽  
Average Grain Size ◽  
Number Of Cycles ◽  
1050 Aluminum Alloy

The cross-ARB (C-ARB) process, which adopts cross rolling of the two stacked plates, has been performed up to seven cycles on a commercial purity 1050 aluminum alloy to obtain ultrafine grains with an average grain size of 0.7μm. Microstructural evolution of the C-ARB processed aluminum alloy was examined by a transmission electron microscopy as a function of process cycle number (accumulated plastic strain). Tensile property of the severely deformed Al alloy was also explored. Grain size of grains of the C-ARB processed alloy varied across thickness of the rolled plate. The size of grains at the top and bottom of the rolled plate converged to 0.65μm, while that of grains at the center of the plate increased with the number of ARB cycles. Tensile strength of the CARB processed 1050 Al alloy increased from 100MPa (as-received) to 160MPa. Tensile elongation varied with the number of cycles, but 15% of failure strain was measured from the 6-cycle C-ARB processed specimen. The variation of the elongation with the cycle number coincided exactly with the variation of grain size at the center of the processed plate.

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