Sains Malaysiana 49(1)(2020): 179-188

http://dx.doi.org/10.17576/jsm-2020-4901-22

Kebolehbentukan-tikso Aloi 2014 dengan Penambahan Si dan Pengurangan Cu

(Thixoformability of 2014 Alloy with the Addition of Si and Decreasing of Cu)

M.A.M. ARIF*, M.Z. OMAR & Z. SAJURI

Centre for Materials Engineering and Smart Manufacturing (MERCU), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

Received: 11 May 2019/Accepted: 12 October 2019

ABSTRAK

Dalam kajian ini, kebolehbentukan-tikso aloi aluminium (Al) 2014 dengan penambahan unsur silikon (Si) dan pengurangan unsur kuprum (Cu) dikaji. Kandungan Si dan Cu dalam aloi 2014 diubah suai supaya kriteria kebolehbentukan-tikso dapat dipenuhi. Kebolehbentukan-tikso aloi 2014 dan aloi Al-terubah suai diukur secara termodinamik dengan menggunakan pakej perisian JMatPro dan seterusnya dibuktikan secara uji kajimelalui analisis terma dan analisis fasa. Hasil kajian ini mendapati bahawa sifat kebolehbentukan-tikso aloi 2014 dapat dipenuhi dengan penambahan Si dan pengurangan Cu. Apabila kandungan Si dalam aloi 2014 bertambah, kandungan fasa eutektik pada titik 'lutut' tertinggi yang terbentuk di atas lengkung pecahan cecair meningkat dengan ketara, manakala julat suhu pemejalan pula semakin mengecil. Di samping itu, pengurangan Cu pula menyebabkan julat suhu pemprosesan untuk pembentukan-tikso menjadi semakin luas lalu mengakibatkan sensitiviti pecahan cecair pada titik 'lutut' tertinggi menurun. Selain pembentukan fasa Al₂Cu dan fasa θ-Al₅Cu₂Mg₈Si₆, kemunculan fasa π-Al₈FeMg₃Si₆ dengan struktur yang padat hasil daripada pengurangan Cu juga dijangka menyumbang kepada peningkatan sifat mekanik aloi Al-terubah suai. Akhir sekali, aloi Al-terubah suai tersebut dijangka mampu digunakan untuk menghasilkan komponen otomotif seperti rod penyambung, aci sesondol dan aci engkol melalui proses pembentukan-tikso. 

Kata kunci: Aloi aluminium; JMatPro; kebolehbentukan-tikso

ABSTRACT

In the present study, the thixoformability of aluminium (Al) alloy 2014 with the addition of silicon (Si) and the reduction of copper (Cu) was studied. The contents of Si and Cu in 2014 alloy were modified in order to fulfil the thixoformability criteria. The thixoformability of 2014 alloy and Al-modified alloy were measured thermodynamically using JMatPro software package and validated experimentally via thermal and phase analysis. The study found that the thixoformability behaviour of alloy 2014 had improved with the addition of Si and Cu reduction. When Si content in the alloy was increased, the amount of eutectic phase at the highest 'knee' on the liquid fraction curve increased significantly, while the solidification temperature range decreased. In addition, the reduction in Cu had increased the temperature range for thixoforming process and lowering the liquid fraction sensitivity at the highest 'knee'. In addition to the existence of Al₂Cu and θ-Al₅Cu₂Mg₈Si₆ phases, the emergence of π-Al₈FeMg₃Si₆ phase with compact structure resulting from Cu reduction is expected could be contribute to the improvement of the Al-modified alloy mechanical properties. Finally, the modified Al alloy is expected to be suitable to produce automotive components such as connecting rod, camshaft and crankshaft by using thixoforming process.

Keywords: Aluminium alloy; JMatPro; thixoformability

REFERENCES

Alhawari, K.S., Omar, M.Z., Ghazali, M.J., Salleh, M.S. & Mohammed, M.N. 2017. Microstructural evolution during semisolid processing of Al-Si-Cu alloy with different Mg contents. Transactions of Nonferrous Metals Society of China 27(7): 1483-1497.

Arif, M.A.M., Omar, M.Z. & Sajuri, Z. 2018. Pembentukan mikrostruktur berbentuk sfera dalam keadaan separa pepejal aloi aluminium Al-4.8Si-2.8Cu-0.5Mg. Jurnal Kejuruteraan 30(2): 275-280.

Arif, M.A.M., Omar, M.Z., Muhamad, N., Syarif, J. & Kapranos, P. 2013. Microstructural evolution of solid-solution-treated Zn–22Al in the semisolid state. Journal of Materials Science & Technology 29(8): 765-774.

ASM Handbook. 2004. Introduction to Aluminum-Silicon Casting Alloys. Volume 2. United States of America: ASM International. Hlm. 1-9.

Chu, K.W.M., Daud, A.R. & Jalar, A. 2008. Pengaruh unsur zirkonium terhadap sifat mekanik aloi tempaan Al-1.2Si-0.5Mg-0.25Fe. Sains Malaysiana 37(2): 189-193.

Daud, A.R., Talib, I.A. & Harun, M. 2001. Effects to magnesium addition on microhardness in Eutectic Al-Si-Mg Alloys. Sains Malaysiana 30: 195-202.

Farkoosh, A.R. & Pekguleryuz, M. 2015. Enhanced mechanical properties of an Al-Si-Cu-Mg alloy at 300°C: Effects of Mg and the Q-precipitate phase. Materials Science & Engineering A 621: 277-286.

Kirkwood, D.H., Suery, M., Kapranos, P., Atkinson, H.V. & Young, K.P. 2010. Semi-Solid Processing of Alloys. London: Springer Series in Materials Science.

Liu, D., Atkinson, H.V. & Jones, H. 2005. Thermodynamic prediction of thixoformability in alloys based on the Al-Si-Cu and Al-Si-Cu-Mg systems. Acta Materialia 53(14): 3807-3819.

Maciel, C.A., Atkinson, H.V., Kapranos, P. & Argent, B.B. 2003. Thermodynamic prediction of wrought alloy compositions amenable to semi-solid processing. Acta Materialia 51(8): 2319-2330.

Mondolfo, L.F. 1976. Aluminium Alloys: Structure and Properties. 1st ed. London: Butterworth-Heinemann.

Omar, M.Z., Atkinson, H.V. & Kapranos, P. 2011. Thixotropy in semisolid steel slurries under rapid compression. Metallurgical and Materials Transactions A 42(9): 2807-2819.

Othman, K., Ghani, J.A., Haron, C.H.C., Juri, A. & Kassim, M.S. 2018. Kajian mikrostruktur aloi aluminium A390 selepas pemesinan kisar. Jurnal Kejuruteraan 30(2): 257-264.

Sadeghi, I., Wells, M.A. & Esmaeili, S. 2017. Modeling homogenization behaviour of Al-Si-Cu-Mg aluminium alloy. Materials & Design 128: 241-249. https://doi.org/10.1016/j.matdes.2017.05.006.

Salleh, E.M., Samsu, Z., Othman, N.K. & Jalar, A. 2018. Kesan suhu celupan ke atas mikrostruktur dan kekerasan salutan aluminium pada keluli karbon. Sains Malaysiana 47(6): 1251-1257.

Salleh, M.S., Omar, M.Z., Syarif, J., Alhawari, K.S. & Mohammed, M.N. 2014. Microstructure and mechanical properties of thixoformed A319 aluminium alloy. Materials & Design 64: 142-152.

Shamsudin, R., Daud, A.R. & Hamid, M.A.A. 2007. Nitridation of Al-Mg-Si alloys through dynamic heating. Sains Malaysiana 36(2): 195-200.

Sjölander, E. & Seifeddine, S. 2010. The heat treatment of Al-Si-Cu-Mg casting alloys. Journal of Materials Processing Technology 210(10): 1249-1259.

Zoqui, E.J., Benati, D.M., Proni, C.T.W. & Torres, L.V. 2016. Thermodynamic evaluation of the thixoformability of Al-Si alloys. Calphad 52: 98-109.

Zuo, L., Ye, B., Feng, J., Kong, X., Jiang, H. & Ding, W. 2017. Effect of Q-Al₅Cu₂Mg₈Si₆ phase on mechanical properties of Al-Si-Cu-Mg alloy at elevated temperature. Materials Science and Engineering A 693: 26-32.

*Corresponding author; email: anifarif@gmail.com