Microstructure analysis of freeze-cast A356 aluminum alloy

YANG Hao-qin; SHAN Zhong-de; LIU Feng; WANG Yi-fei

doi:10.13374/j.issn2095-9389.2021.01.16.002

Volume 44 Issue 8

Aug. 2022

Turn off MathJax

Article Contents

Article Navigation > Chinese Journal of Engineering > 2022 > 44(8): 1331-1337

YANG Hao-qin, SHAN Zhong-de, LIU Feng, WANG Yi-fei. Microstructure analysis of freeze-cast A356 aluminum alloy[J]. Chinese Journal of Engineering, 2022, 44(8): 1331-1337. doi: 10.13374/j.issn2095-9389.2021.01.16.002

Citation:

YANG Hao-qin, SHAN Zhong-de, LIU Feng, WANG Yi-fei. Microstructure analysis of freeze-cast A356 aluminum alloy[J]. Chinese Journal of Engineering, 2022, 44(8): 1331-1337. doi: 10.13374/j.issn2095-9389.2021.01.16.002

Citation:

PDF( 3575 KB)

Microstructure analysis of freeze-cast A356 aluminum alloy

doi: 10.13374/j.issn2095-9389.2021.01.16.002

YANG Hao-qin^{1, 2
,
,},
SHAN Zhong-de^{1, 2},
LIU Feng^{2, 3},
WANG Yi-fei^{2, 3}

1.
College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
2.
State Key Laboratory of Advanced Forming Technology and Equipment, Beijing 100083, China
3.
China Academy of Machinery Science and Technology Group Co. Ltd, Beijing 100044, China

More Information

Corresponding author: E-mail: Yang-haoqin@nuaa.edu.cn
Received Date: 2021-09-16
Available Online: 2021-04-16
Publish Date: 2022-07-06

Abstract

Abstract

In combination with the digital and green development needs of the foundry industry, this article proposes a digital patternless freezing casting method. In this method, mixed water green sand particles are frozen and transformed to a certain strength in a low-temperature environment, which are then directly cut through a sand mold CAD three-dimensional model. Pouring to obtain castings with dimensional accuracy that meets the requirements, this is a new technology, new process, and new method in the field of casting. With the fast development of the rapid and sub-rapid solidification technology of metals, the nonequilibrium solidification theory of liquid–solid transformation during the preparation of metals and alloy materials has been developed by leaps and bounds. Using some special nonequilibrium solidification techniques to prepare metal parts, and to make metal parts with a special structure that traditional casting does not have, can improve the materials’ properties and structures. The nonequilibrium solidification mechanism based on the freezing casting technology is not yet clear. Based on the nonequilibrium solidification process of the freezing casting principle, a higher cooling rate will considerably affect the heat transfer and mass transfer behavior of casting during solidification, which will then considerably affect the alloy micro component distribution and fracture morphology, ultimately affecting the service performance of the alloy material. Based on the digital precision forming technology of patternless frozen casting, this paper realized the rapid forming of the frozen sand mold. Frozen casting flat castings were obtained by pouring the A356 high-temperature aluminum alloy. The distribution of trace elements in frozen and resin sand castings was characterized by electron probe microanalysis, and the fracture morphology of frozen and resin sand castings was analyzed. Results show that the solubility of the Si element in the aluminum matrix phase of freeze casting is significantly higher than that of resin sand casting. In addition, the distribution of the Mg element in freeze casting is more uniform than that in resin sand casting, and there are more segregation areas of the Mg element composition in resin sand casting specimens. The fracture morphology of freeze-cast specimens is a mixed fracture mode of toughness and brittleness. Meanwhile, the fracture morphology of resin sand casting specimens has a cleavage step failure morphology and rectangular tear structure morphology, and the alloy tends to exhibit a brittle fracture.
- freezen casting,
- patternless forming,
- green casting,
- composition distribution,
- fracture morphology

FullText(HTML)

References(26)

References

[1]	Shan Z D, Qin S Y, Liu Q, et al. Key manufacturing technology & equipment for energy saving and emissions reduction in mechanical equipment industry. Int J Precis Eng Manuf, 2012, 13(7): 1095 doi: 10.1007/s12541-012-0143-y
[2]	Torielli R M, Abrahams R A, Smillie R W, et al. Using lean methodologies for economically and environmentally sustainable foundries. China Foundry, 2011, 8(1): 74
[3]	單忠德, 朱福先. 應用PCD 刀具銑削砂型的刀具磨損機理和預測模型. 機械工程學報, 2018, 54(17):124 doi: 10.3901/JME.2018.17.124 Shan Z D, Zhu F X. Wear mechanism and prediction model of polycrystalline diamond tool in milling sand mould. J Mech Eng, 2018, 54(17): 124 doi: 10.3901/JME.2018.17.124
[4]	Liu L M, Shan Z D, Liu F, et al. High-quality manufacturing method of complicated castings based on multi-material hybrid moulding process. China Foundry, 2018, 15(5): 343 doi: 10.1007/s41230-018-8053-y
[5]	Guo Z, Shan Z D, Liu F, et al. Experimental investigation on the performance and mesostructure of multi-material composite 3D-printed sand mold. Rapid Prototyp J, 2019, 26(2): 309 doi: 10.1108/RPJ-10-2018-0265
[6]	Shan Z D, Guo Z, Du D, et al. Digital high-efficiency print forming method and device for multi-material casting molds. Front Mech Eng, 2020, 15(2): 328 doi: 10.1007/s11465-019-0574-6
[7]	單忠德. 無模鑄造. 北京: 機械工業出版社, 2017 Shan Z D. Patternless Casting. Beijing: China Machine Press, 2017
[8]	Shan Z D, Yang H Q, Liu F, et al. Performance of digital patternless freeze-casting sand mould. China Foundry, 2020, 17(4): 308 doi: 10.1007/s41230-020-9163-x
[9]	Yang H Q, Shan Z D, Wang Y F, et al. Simulation of temperature field of A356 aluminum alloy in freeze casting // 4th International Conference on Fluid Mechanics and Industrial Applications. Taiyuan, 2020, 1600(1): 012045
[10]	楊浩秦. 數字化無模冷凍鑄造成形機理研究 [學位論文]. 北京: 機械科學研究總院, 2020 Yang H Q. Study on Forming Mechanism of Digital Patternless Freezing Casting [Dissertation]. Beijing: China Academy of Machinery Science and Technology, 2020
[11]	郭莉軍, 單忠德, 劉麗敏, 等. 型砂材質與擠壓成形工藝對砂型表面性能的影響. 工程科學學報, 2021, 43(2):273 Guo L J, Shan Z D, Liu L M, et al. Effect of sand-mold material and extrusion forming process on sand-mold surface properties. Chin J Eng, 2021, 43(2): 273
[12]	單忠德, 楊浩秦, 劉豐, 等. 數字化無模冷凍鑄造成形方法研究. 稀有金屬材料與工程, 2020, 49(12):4321 Shan Z D, Yang H Q, Liu F, et al. Research on forming method of digital patternless freezing casting. Rare Met Mater Eng, 2020, 49(12): 4321
[13]	Zhang J, Zhang D Q, Wu P W, et al. Numerical simulation research of investment casting for TiB₂/ A356 aluminum base composite. Rare Met Meter Eng, 2014, 43(1): 47 doi: 10.1016/S1875-5372(14)60050-3
[14]	Samuel E, Golbahar B, Samuel A M, et al. Effect of grain refiner on the tensile and impact properties of Al−Si−Mg cast alloys. Mater Des (1980—2015), 2014, 56: 468
[15]	Jones H. Cooling rates during rapid solidification from a chill surface. Mater Lett, 1996, 26(3): 133 doi: 10.1016/0167-577X(95)00213-8
[16]	賈麗敏, 徐達鳴, 郭景杰, 等. 離心鑄造TC4合金冷速對其組織和力學性能的影響. 中國有色金屬學報, 2010, 20(4):667 Jia L M, Xu D M, Guo J J, et al. Effect of cooling rate on structure and tensile strength of centrifugally cast TC4 alloy in ceramic-shell mold. Chin J Nonferrous Met, 2010, 20(4): 667
[17]	Chen Z W, Lei Y M, Zhang H F. Structure and properties of nanostructured A357 alloy produced by melt spinning compared with direct chill ingot. J Alloys Compd, 2011, 509(27): 7473 doi: 10.1016/j.jallcom.2011.04.082
[18]	李曉燕, 盧雅琳, 王健, 等. 稀土Er對A356鋁合金微觀組織和力學性能的影響. 材料工程, 2018, 46(1):67 doi: 10.11868/j.issn.1001-4381.2016.001066 Li X Y, Lu Y L, Wang J, et al. Effect of rare earth erbium on microstructure and mechanical properties of A356 aluminum alloy. J Mater Eng, 2018, 46(1): 67 doi: 10.11868/j.issn.1001-4381.2016.001066
[19]	Kobayashi T. Strength and fracture of aluminum alloy. Mater Sci Eng:A, 2000, 280(1): 8 doi: 10.1016/S0921-5093(99)00649-8
[20]	Jiang W M, Fan Z T, Liu D J. Microstructure, tensile properties and fractography of A356 alloy under as-cast and T6 obtained with expendable pattern shell casting process. Trans Nonferrous Met Soc China, 2012, 22(Suppl 1): s7
[21]	王正軍, 司乃潮, 王俊, 等. 動態復合細化變質對A356鋁合金顯微組織的影響. 材料工程, 2017, 45(1):20 doi: 10.11868/j.issn.1001-4381.2015.000077 Wang Z J, Si N C, Wang J, et al. Effect of dynamic composite refinement and modification on microstructure of A356 aluminum alloy. J Mater Eng, 2017, 45(1): 20 doi: 10.11868/j.issn.1001-4381.2015.000077
[22]	王長海, 倪紅軍, 孫寶德, 等. 鋁熔體除氫技術的進展. 鑄造, 2001, 50(4):179 doi: 10.3321/j.issn:1001-4977.2001.04.001 Wang C H, Ni H J, Sun B D, et al. Development in method and technology of aluminum melt hydrogen-removal. Foundry, 2001, 50(4): 179 doi: 10.3321/j.issn:1001-4977.2001.04.001
[23]	Menargues S, Martín E, Baile M T, et al. New short T6 heat treatments for aluminium silicon alloys obtained by semisolid forming. Mater Sci Eng:A, 2015, 621: 236 doi: 10.1016/j.msea.2014.10.078
[24]	Wang H P, Yao W J, Wei B. Remarkable solute trapping within rapidly growing dendrites. Appl Phys Lett, 2006, 89(20): 201905 doi: 10.1063/1.2387971
[25]	王韜濤. 鋁合金顯微氣孔演化數值模擬及其軟件開發[學位論文]. 南京: 東南大學, 2016 Wang T T. Numerical Modeling and Simulation Software Development of Microporosity Eveolution in Aluminum Alloy [Dissertation ]. Nanjing: Southeast University, 2016
[26]	Liao H C, Wu Y N, Ding K. Hardening response and precipitation behavior of Al–7%Si–0.3%Mg alloy in a pre-aging process. Mater Sci Eng: A, 2013, 560: 811