Role of Metal Quality and Porosity Formation in Low Pressure Die Casting of A356: Experimental Observations

• Autorzy: Gursoy O. , Nordmak A. , Syversten F. , Colak M. , Tur K. , Dispinar D.

Identyfikatory

DOI

10.24425/afe.2021.136071

• Języki publikacji: EN

Abstrakty

EN

Porosity is one of the major problems in casting operations and there are several discussions in the literature about the porosity formation in aluminum castings. Bifilms are the defects that are introduced into the melt by turbulence. They can be detected with reduced pressure test and presented numerically by measuring bifilm index. The measure of bifilm index is the sum of total oxide length given in millimeters from the cross-section of reduced pressure test sample solidified under 0.01 MPa. In this work, low pressure die casting (LPDC) unit was built in an attempt to enhance the producibility rate. The unit consists of a pump housing that was placed inside the melt in the melting furnace where the pressure was applied instead of the whole melt surface. It was observed that the melt quality of A356 alloy was deteriorated over time which had led to higher porosity. This was attributed to the increased oxide thickness of the bifilm by the consumption of air in between the folded oxides. A relationship was found between bifilm index and pore formation.

Słowa kluczowe

EN

die casting; alloy A356; solidification; LPDC; aluminium; quality of alloy; bifilm; porosity

PL

odlewanie ciśnieniowe; stop A356; krzepnięcie; aluminium; właściwości stopu; porowatość

• Wydawca: Komisja Odlewnictwa Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2021
• Tom: Vol. 21, iss. 1
• Strony: 5--10
• Opis fizyczny: Bibliogr. 29 poz., fot., rys., wykr.

Twórcy

autor

Gursoy O.

• University of Padova, Italy

autor

Nordmak A.

• SINTEF, Norway

autor

Syversten F.

• SINTEF, Norway

autor

Colak M.

• University of Bayburt, Turkey

autor

Tur K.

• Atilim University, Turkey

autor

Dispinar D.

• Istanbul Technical University, Turkey

Bibliografia

• [1] Campbell, J. (2011). Complete Casting Handbook: Metal Casting Processes. Techniques and Design. Elsevier Science.
• [2] Bonollo, F., Urban, J., Bonatto, B. & Botter, M. (2005). Gravity and low pressure die casting of aluminium alloys: a technical and economical benchmark. La Metallurgia Italiana. 6, 23-32.
• [3] Dispinar, D. & J. Campbell, (2004). Critical assessment of reduced pressure test. Part 2: Quantification. International Journal of Cast Metals Research. 17(5), 287-294.
• [4] Raiszadeh, R., & Griffiths, W.D. (2006). A method to study the history of a double oxide film defect in liquid aluminum alloys. Metallurgical and Materials Transactions B. 37(6), 865-871.
• [5] Raiszadeh, R., & Griffiths, W.D. (2008). A semi-empirical mathematical model to estimate the duration of the atmosphere within a double oxide film defect in pure aluminum alloy. Metallurgical and Materials Transactions B. 39(2), 298-303.
• [6] Raiszadeh, R., & Griffiths, W.D. (2011). The effect of holding liquid aluminum alloys on oxide film content. Metallurgical and Materials Transactions B. 42(1), 133-143.
• [7] Aryafar, M., Raiszadeh, R., & Shalbafzadeh, A. (2010). Healing of double oxide film defects in A356 aluminium melt. Journal of materials science. 45(11), 3041-3051.
• [8] Farhoodi, B., Raiszadeh, R., & Ghanaatian, M. H. (2014). Role of double oxide film defects in the formation of gas porosity in commercial purity and Sr-containing Al alloys. Journal of Materials Science & Technology. 30(2), 154-162.
• [9] Amirinejhad, S., Raiszadeh, R., & Doostmohammadi, H. (2013). Study of double oxide film defect behaviour in liquid Al–Mg alloys. International Journal of Cast Metals Research. 26(6), 330-338.
• [10] Bakhtiarani, F.N., & Raiszadeh, R. (2011). Healing of double-oxide film defects in commercial purity aluminum melt. Metallurgical and Materials Transactions B. 42(2), 331-340.
• [11] Bagherpour-Torghabeh, H., Raiszadeh, R., & Doostmohammadi, H. (2017). Role of Mechanical Stirring of Al-Mg Melt in the Healing of Bifilm Defect. Metallurgical and Materials Transactions B. 48(6), 3174-3184.
• [12] Nateghian, M., Raiszadeh, R., & Doostmohammadi, H. (2012). Behavior of Double-Oxide Film Defects in Al-0.05 wt pct Sr Alloy. Metallurgical and Materials Transactions B. 43(6), 1540-1549.
• [13] Stefanescu, D.M. (2005). Computer simulation of shrinkage related defects in metal castings - a review. International Journal of Cast Metals Research. 18, 129-143.
• [14] Zhu, J.D., Cockcroft, S.L., Maijer, D.M. & Ding, R. (2005). Simulation of microporosity in A356 aluminium alloy castings. International Journal of Cast Metals Research. 18, 229-235.
• [15] Merlin, M., Timelli, G., Bonollo, F. & Garagnani, G.L. (2009). Impact behaviour of A356 alloy for low-pressure die casting automotive wheels. Journal of Materials Processing Technology. 209(2), 1060-1073.
• [16] Zhang, B., Maijer, D.M. & Cockcroft, S.L. (2007). Development of a 3-D thermal model of the low-pressure die-cast (LPDC) process of A356 aluminum alloy wheels. Materials Science and Engineering: A, 464(1-2), 295-305.
• [17] Zhang, B., Cockcroft, S.L., Maijer, D.M., Zhu, J.D. & Phillion, A.B. Casting defects in low-pressure die-cast aluminum alloy wheels. JOM Journal of the Minerals, Metals and Materials Society, 57(11), 36-43.
• [18] Campbell, J. (1968). Hydrostatic tensions in solidifying materials. Transactions of the Metallurgical Society of AIME, 242(February), 264-267.
• [19] Campbell, J. (1968). Hydrostatic tensions in solidifying alloys. Transactions of the Metallurgical Society of AIME, 242(February), 268-271.
• [20] Campbell, J. (1967), Shrinkage pressure in castings (The solidification of a Metal Sphere). Transactions of the Metallurgical Society of AIME, 239 (February), 138-142.
• [21] Dispinar, D. & Campbell, J. (2004). Critical assessment of reduced pressure test. Part 1: Porosity phenomena. International Journal of Cast Metals Research. 17(5), 280-286.
• [22] Dispinar, D., Akhtar, S., Nordmark, A., Di Sabatino, M., & Arnberg, L. (2010). Degassing, hydrogen and porosity phenomena in A356. Materials Science and Engineering: A. 527(16-17), 3719-3725.
• [23] Puga, H., Barbosa, J., Azevedo, T., Ribeiro, S. & Alves, J.L. (2016). Low pressure sand casting of ultrasonically degassed AlSi7Mg0. 3 alloy: Modelling and experimental validation of mould filling. Materials & Design. 94, 384-391.
• [24] El-Sayed, M.A. & Essa, K. (2018). Effect of mould type and solidification time on bifilm defects and mechanical properties of Al–7si–0.3 mg alloy castings. Computational and Experimental Studies, 23.
• [25] Gyarmati, G., Fegyverneki, G., Mende, T. & Tokár, M. (2019). Characterization of the double oxide film content of liquid aluminum alloys by computed tomography. Materials Characterization. 157, 109925.
• [26] Gyarmati, G., Fegyverneki, G., Tokár, M., & Mende, T. (2020). The Effects of Rotary Degassing Treatments on the Melt Quality of an Al–Si Casting Alloy. International Journal of Metalcasting. 1-11.
• [27] Tiryakioğlu, M. (2020). The Effect of Hydrogen on Pore Formation in Aluminum Alloy Castings: Myth Versus Reality. Metals. 10(3), 368.
• [28] Tiryakioğlu, M. (2019). Solubility of hydrogen in liquid aluminium: reanalysis of available data. International Journal of Cast Metals Research. 32(5-6), 315-318.
• [29] Tiryakioğlu, M. (2020). A simple model to estimate hydrogen solubility in liquid aluminium alloys. International Journal of Cast Metals Research. 1-3.

Uwagi

Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2021).