Investigation of Properties of Thixoprocessed LM4

A.V. Adedayo, S.A. Ibitoye, O.O. Oluwole, K.M. Oluwasegun

Department of Materials Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria.
Department of Mechanical Engineering, University of Ibadan, Ibadan, Nigeria.

DOI: 10.4236/jmmce.2012.111008                

Abstract

Thermomechanical treatment on cast Al-Si-Cu alloy (LM4) was carried out. The aim is to determine effects of degree of cold work, slurry thermal treatment and soaking time on the tensile strength, ductility, hardness and microstructure of the alloy. LM4 was prepared and cast in sand mould into rods of Φ50 mm and 200 mm in length. The prepared rods were then thermally treated at 635°C which fall within the slurry region of the alloy. The heated samples were soaked at this temperature for various times of: 5, 10, 15 and 20 min. A none-treated sample was also kept as control specimen. The thermally treated rods were subjected to various degrees of cold work. 10 %, 15%, 20%, 30% degrees of cold work were used. Hardness, tensile strength and elongation of the samples were determined. The metallographic examination of the samples was also carried out. Results of mechanical property test show sensitivity to degree of cold work, thermal treatment soaking time. The microstructures of the alloy also show significant modifications as a result of thermal treatment.

Keywords

SSM, thixocasting, rheocasting

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Adedayo, A.V. 2011 Development processes of globular microstructure, Journal of Minerals, Materials Characterization and Engineering, Vol.10, No. 7, pp 651-659
[2]	Adedayo, A.V. 2011 Influence of furnace design on semi solid microstructure, Pacific Journal of Science and Technology, Vol. 12, No. 1, pp 76 -79
[3]	Oblak, J.M.; Rand, W.H. 1976 Solid-liquid phase characterization of several rheocast high performance alloys, Metallurgical Transaction B, vol.7 pp 699 -703
[4]	Reisi, M. Niroumand, B. 2008 Effects of stiring parameters on rheocast structure, Journal of Alloys and Compounds, Vol 32, No. 1, pp 41-47
[5]	Margarido, M.; Robert, M.H. 2003 The production of alloys with rheocast structure. Journal of Brazilian Society for Mechanical Sciences and Engineering, Vol 25, No. 2, pp 207-214
[6]	Paes, M. Santos, E.G. Zoqui, E.J. 2006 Obtention rheocast structure for Al Cu alloys, Journal of Achievements in Materials and Manufacturing Engineering, Vol. 19, No. 2 pp 21-26
[7]	Yurko, J.A.; Martinez, R.A.; Flemings, M.C. 2003 Commercial development of the semi solid rheocasting (SSR) process, Metallurgical Science and Technology, Vol. 21, No 3. pp 10-15
[8]	Flemings, M.C. 2000 Semi solid forming: the process and the path forward. Metallurgical Science and Technology, Vol. 18, No 2., pp.3-4
[9]	Czerwinski, F. 2008 The basics of modern SSMP, Journal of the Minerals, Metals and Materials Society, Volume 60, Number 11, pp. 82-86
[10]	Browne, A.J.; Hussey, M.J.; Carr, A.J. Bradazon, D. 2003 Direct thermal method: new process for development of globular alloy microstructure; International Journal of Cast Metals Research, Vol.16, No 4, pp 418-426.
[11]	Chama, C.C. 1998 Journal of Materials Science Letters, Vol.17, No.21, pp1857
[12]	British Standard 1988: http://www.britishstandard/BS 1490:1988/
[13]	Mittal, R. 2009 Strengthening mechanism of metals physical metallurgy, metallurgy & materials engineering, National Institute of Technology, Rourkela, Roll No: 10604038, pp 56
[14]	Callister, W.J. 1985 Materials science and engineering, an introduction. John Wiley & Sons, NY pp 717
[15]	Adedayo, A.V. 2010 Effects of addition of iron filings to green moulding sand on the microstructure of grey iron, Journal of the Brazilian Society for Mechanical Sciences and Engineering, Vol. 32, No 2, pp 171-175
[16]	Adedayo, A.V. 2009 Effects of Iron Filings on the Properties of Green Moulding Sand, Proceedings of 2nd National Conference of Institute of Technology, Kwara State Polytechnic, Ilorin, Vol. 2, No 1, pp 45-49
[17]	Adedayo, A.V.; Adesina, S.A.; Alagbe, M.; Ekpenyong, J.E. 2008 Adaptation of Asa-Dam River Side Sand for Engineering Use (Paper I), Proceedings of 1st National Conference of Institute of Technology, Kwara Sate Polytechnic, Ilorin, Vol 1, No 1, pp 186-190
[18]	Liu, Z.K.; Hoglund, L.; Jonsson, B.; Agren, J. 1991 An experimental and theorectical study of cementite dissolution. Metal Transactions A. 22A pp 1745 -1752