Microstructure, SDAS and Mechanical Properties of A356 alloy Castings Made in Sand and Granulated Blast Furnace Slag Moulds

Open access

Abstract

Investigations were carried out to ensure the granulated blast furnace (GBF) slag as an alternative mould material in foundry industry by assessing the cast products structure property correlations. Sodium silicate-CO2 process was adopted for preparing the moulds. Three types of moulds were made with slag, silica sand individually and combination of these two with 10% sodium silicate and 20 seconds CO2 gassing time. A356 alloy castings were performed on these newly developed slag moulds. The cast products were investigated for its metallography and mechanical properties. Results reveal that cast products with good surface finish and without any defects were produced. Faster heat transfers in slag moulds enabled the cast products with fine and refined grain structured; and also, lower Secondary Dendrite Arm Spacing (SDAS) values were observed than sand mould. Slag mould casting shows improved mechanical properties like hardness, compression, tensile and impact strength compared to sand mould castings. Two types of tensile fracture modes, namely cleavage pattern with flat surfaces representing Al−Si eutectic zone and the areas of broken Fe-rich intermetallic compounds which appear as flower-like morphology was observed in sand mould castings. In contrast, GBF slag mould castings exhibit majority in dimple fracture morphology with traces of cleavage fracture. Charpy impact fractured surfaces of sand mould castings shows both transgranular and intergranular fracture modes. Only intergranular fracture mode was noticed in both GBF slag and mixed mould castings.

[1] Fan Zitian, Huang Naiyu & Dong Xuanpu, (2004). In house reuse and reclamation of used foundry sands with sodium silicate binder. International Journal of Cast Metals Research. 17, 51-56.

[2] Ahmed, S. & Ramrattan, S.N. (1990). Comparison of Handling Properties Using CO2 Activated Binder Systems, AFS Transactions. 98, 577-586.

[3] Narasimha Murthy, I. & Babu Rao J. (2015). Investigations on Physical and Chemical Properties of High Silica Sand, Fe-Cr Slag and Blast Furnace Slag for Foundry Applications. Resource Efficient Waste Management. Nov 2015, 553-561.

[4] Narismha Murthy, I., Arun Babu, N., Babu Rao J. (2015). High carbon Ferro Chrome Slag and GBF Slag - Alternative Mould Material for Foundry Industry - 5th International Conference on Solid Waste Management, (5th IconSWM 2015), Bangalore, India, 24 - 27 November, 2015, p. 62.

[5] Adedayo, A.V. & Aremo B. (2011). Influence of Mould Heat Storage Capacity on Properties of Grey Iron. Journal of Minerals & Materials Characterization & Engineering. 10(4), 387-396.

[6] HU Xiaowu, AI Fanrong, & YAN Hong, (2012). Influences of pouring temperature and cooling rate on microstructure and mechanical properties of casting Al-Si-Cu aluminum alloy, Acta Metall. Sin.(Engl. Lett.). 25(4), 272-278.

[7] Wasiu Ajibola Ayoola, Samson Olurropo Adeosun, Olujide Samuel Sanni, & Akinlabi Oyetuni (2012). Effect of Casting Mould on Mechanical Properties of 6063 Aluminium alloy, Journal of Engineering Science and Technology. 7(1), 89-96.

[8] Ying-Dong Qu, Mei-Ling Jin, Gang Qin, Rong-De Li, Min- Qiang Gao, Feng-Shuang Sun, & Jun-Hua You (2014). Ultra-Long Pore Fabrication Process by Pulling-Casting in Aluminum Alloy. Materials and Manufacturing Processes. 29(10), 1205-1209.

[9] Minghui Ding, Jingtao Song, & Liu Honghui, (2014). Effect of Pouring Temperature on Typical Structure of Thin-Walled ZL105A Alloy Casting. Materials and Manufacturing Processes. 29(7), 853-863.

[10] Ahmad, H., Naher, S. & Brabazon, D. (2014). The Effect of Direct Thermal Method, Temperature and Time on Microstructure of a Cast Aluminum Alloy. Materials and Manufacturing Processes. 29(2), 134-139.

[11] Rao A. Shailesh, S Mahantesh. Tattimani, S Shrikantha Rao (2015). Understanding Melt Flow Behavior for Al-Si Alloys Processed Through Vertical Centrifugal Casting. Materials and Manufacturing Processes. 30(11), 1305-1311.

[12] Hsien-Chi Sun, & Long-Sun Chao, (2009), An Investigation into the Effective Heat Transfer Coefficient in the Casting of Aluminum in a Green-Sand Mold, Materials Transactions. The Japan Institute of Metals. 50(6), 1396-1403.

[13] Mondolfo, L.F. (1943). Metallography of Aluminum Alloys, New York John Wiley & sons, Inc.

[14] Ye Haizhi (2003). An Overview of the Development of Al- Si-Alloy Based Material for Engine Applications. Journal of Materials Engineering and Performance, ASM International. 12(3), 288-297.

[15] Mae, H., Teng, X., Bai, Y. & Wierzbicki, (2008). Comparison of ductile fracture properties of aluminium castings: sand mold vs. metal mold. Int. Journal of Solids and Structures. 45, 1430-1444.

[16] Casting. ASM Hand book (1992). vol 15, ASM International.

[17] D. Hanumantha Rao., G.R.N Tagore., G Ranga Janardhana (2010). Evolution of Artificial Neural Network (ANN) model for predicting secondary dendrite arm spacing in aluminium alloy casting. J. Braz. Soc. Mech. Sci. & Eng. 32(3), 276-281.

[18] Kadushnikov, M., Alievskiĭ, V.M., Somina, S.V., Kozerchuk, A.L. & Petrov, M.S. (2011). Digital microscopy from Nano to macro, using the SIAMS image-analysis system. Journal of Optical Technology. 78(1), 61-65.

[19] Yildirim, M. & Özyürek, D. (2014). The effects of mould materials on microstructure and mechanical properties of cast A356 alloy. Journal of Advanced Materials and Processing. 2(4), 3-12.

[20] M.N. Shetty, (2013). Dislocations and Mechanical behavior of Materials, Delhi, India, PHI Learning, Pvt. Ltd.

[21] Weng-ming JIANG, Zi-tian FAN, & De-jun LIU (2012), Microstructure, tensile properties and fractography of A356 alloy under as-cast and T6 obtained with expendable pattern shell casting process. Transaction of nonferrous metals society of china. 22, 7-13.

[22] Wenming Jiang, Zitian Fan, Dejun Liu, Defeng Liao, Xuanpu Dong, & Xiaoming Zong, (2013). Correlation of microstructure with mechanical properties and fracture behavior of A356-T6 aluminum alloy fabricated by expendable pattern shell casting with vacuum and lowpressure, gravity casting and lost foam casting. Materials Science and Engineering: A. 560, 396-403.

[23] Ji-hua Peng, Xiao-long Tang, Jian-ting HE, & De-ying XU (2011), Effect of heat treatment on microstructure and Tensile properties of A356 alloys. Transaction of nonferrous metals society of china. 21, 1950-1956.

[24] Wang, Q.G. (2003). Microstructural Effects on the Tensile and Fracture Behavior of Aluminum Casting Alloys A356/357. Metallurgical and Materials Transactions A. 34 A, 2887-2899.

[25] Guo-hua Zhang, Jian-xin Zhang, LI Bing-chao, & Wei Cai (2011). Characterization of tensile fracture in heavily alloyed Al-Si piston alloy. Progress in natural science: Materials International. 21, 380-385.

[26] Merlin M., & Garagnani, G.L. (2009). Mechanical and microstructural characterization of A356 castings realized with full and empty cores. Metallurgical Science and Technology. 127(1), 21-30.

[27] Ceschini, L., Jarfors, A., Al Morri, Al., Morri, An,, Rotundo, F., Seifeddine, S. & Toschi, S. (2014). High temperature tensile behaviour of the A354 aluminum alloy. Materials Science Forum. 794-796, 443-448.

[28] Casari, D., Merlin, M. & Garagnani, G.L. (2013). A comparative study on the effects of three commercial Ti-Bbased grain refiners on the impact properties of A356 cast aluminium alloy. Journal of Mater Science. 48, 4365-4377.

[29] 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.

[30] Alexopoulos, D.N. (2010). Impact properties of the aircraft cast aluminium alloy Al-7Si-0.6Mg (A357). EPJ Web of Conferences. 02002(6), 1-8.

[31] M Amne Elahi, S.G. Shabestari, (2016). Effect of various melt and heat treatment conditions on impact toughness of A356 aluminum alloy. Trans. Nonferrous Met. Soc. China. 26, 956-965.

Archives of Foundry Engineering

The Journal of Polish Academy of Sciences

Journal Information


CiteScore 2016: 0.42

SCImago Journal Rank (SJR) 2016: 0.192
Source Normalized Impact per Paper (SNIP) 2016: 0.316

Cited By

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 279 279 31
PDF Downloads 117 117 13