Investment casting is a highly flexible process which was previously perceived as an expensive process. However, when the process is compared to other optional processes which may require machining or welding, this casting can produce metallic components at highly competitive costs. There are many process variables which affect the process such as die temperature, wax temperature, injection pressure, shell firing temperature and time, cooling rate. In this study, important shell parameters such as preheat temperature, firing temperature and firing time, and melt pouring temperature have been chosen as process variables influencing the quality of the hypoeutectic aluminium–silicon alloy investment casting. The optimal input parametric condition for reduction of linear and volumetric shrinkages and increment of tensile strength of Al–Si 7%–Mg investment casting has been identified as shell preheat temperature of 200 °C, firing temperature of 900 °C, firing time of 7 h and pouring temperature of 600 °C. At this optimal setting, it was found that linear and volumetric shrinkages decreased from 0.65 and 1.89% to 0.381 and 1.546%. The tensile strength of the casting increased from 96 to 121 MPa with regard to the nine experimental runs performed. Microstructural observation revealed that higher shell preheat and pouring temperatures led to augmented porosity, increased secondary dendrite arm spacing (35.53 ± 2.4 μm), larger detrimental iron-rich intermetallics (40.49 ± 25.15 μm) followed by reduced tensile properties of the casting (96 MPa).
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Casting (1998) ASM international, ASM metals handbook, vol 15. The Materials Information CompanyGoogle Scholar
Calcom SA (2001) Simulating porosity in ductile iron castings. Parc Scientifique EPFL, CH-1015 Lausanne, SwitzerlandGoogle Scholar
Pattnaik SR, Karunakar DB, Jha PK (2012) Developments in investment casting process—a review. J Mater Process Technol 212:2332–2348CrossRefGoogle Scholar
Pattnaik SR, Karunakar DB, Jha PK (2013) Multi-characteristic optimization of wax patterns in the investment casting process using grey–fuzzy logic. Int J Adv Manuf Technol 67:1577–1587CrossRefGoogle Scholar
Dong YW, Li XL, Zhao Q, Yang J, Dao M (2017) Modeling of shrinkage during investment casting of thin-walled hollow turbine blades. J Mater Process Technol 244:190–203CrossRefGoogle Scholar
Bonilla W, Masood SH, Iovenitti P (2001) An investigation of wax patterns for accuracy improvement in investment cast parts. Int J Adv Manuf Technol 18:348–356CrossRefGoogle Scholar
Rezavand SAM, Behravesh AH (2007) An experimental investigation on dimensional stability of injected wax patterns of gas turbine blades. J Mater Process Technol 182:580–587CrossRefGoogle Scholar
Yarlagadda PKDV, Hock TS (2003) Statistical analysis on accuracy of wax patterns used in investment casting process. J Mater Process Technol 138:75–81CrossRefGoogle Scholar
Pattnaik SR, Karunakar DB, Jha PK (2013) Influence of injection process parameters on dimensional stability of wax patterns made by the lost wax. Proc Inst Mech Eng L J Mater Des Appl 227(1):52–60CrossRefGoogle Scholar
Cheng X, Yuan C, Shevchenko D, Withey P (2014) The influence of mould pre-heat temperature and casting size on the interaction between a Ti–46Al–8Nb–1B alloy and the mould comprising an Al2O3 face coat. Mater Chem Phys 146:295–302CrossRefGoogle Scholar
Casting Design and Performance (2009) ASM international. The Materials Information Society, Page, p 62Google Scholar
Das S, Mondal DP, Sawla S, Ramkrishnan N (2008) Synergic effect of reinforcement and heat treatment on the two body abrasive wear of an Al–Si alloy under varying loads and abrasive sizes. Wear 264:47–59CrossRefGoogle Scholar