Influence of injection process parameters on dimensional stability of wax patterns made by the lost wax process using Taguchi approach

Abstract

Investment casting is a manufacturing technique employed to produce near net shape metal components. Wax is the most widely used pattern material. In the present work, the wax blend, to be used in the investment casting process, is prepared by mixing different waxes and starch as filler material to reduce the shrinkage of wax patterns. The effect of the selected injection process parameters on the dimensional stability of the wax patterns made by the investment casting process using silicon rubber mould has been studied and the optimum injection process parameters to reduce the shrinkage of wax patterns have been suggested. The wax injection processing parameters considered for experimentation were injection temperature, injection pressure and injection time. Taguchi's L9 orthogonal array was used for designing the experiments. The signal-to-noise and the analysis of variance were used to find the optimum levels and to indicate the impact of the process parameters on shrinkage of wax patterns. The confirmation tests were conducted and the results were found to be within the confidence interval. The analysis of experimental results showed that the injection temperature and injection pressure greatly influenced the dimensional stability of wax patterns.

Keywords

Investment casting wax blend silicon rubber mould injection parameters Taguchi method

Get full access to this article

View all access options for this article.

References

Clegg

. Precision casting processes , Oxford: Pergamon Press, 1991.

Wolff

. Influences which eliminate wax pattern defects. Incast 1999; 12(2): 22–24.

Borcherding

Luck

. Application of plant proteins as thermoplastics. Plant Protein Eur Crops 1998; 6: 313–318.

Tascioglu

Akar

. Conversion of an investment casting sprue wax to a pattern wax by chemical agents. Mater Manuf Process 2003; 18(5): 753–768.

Tascioglu

Akar

. A novel alternative to the additives in investment casting pattern wax compositions. Mater Design 2003; 24: 693–698.

Singh

Kumar

Mishra

. Experimental investigation of wax blends in investment casting process. Indian Foundry J 2006; 52(3): 29–36.

Horacek M and Lubos S. Influence of injection parameters on the dimensional stability of wax patterns. In: 9th World Conference on Investment Casting, San Francisco, California, 1996.

Rezavand

SAM

Behravesh

. An experimental investigation on dimensional stability of injected wax patterns of gas turbine blades. J Mater Process Tech 2007; 182: 580–587.

Horacek M. Accuracy of castings manufactured by lost wax process. In: Proceedings of the 23rd BICTA conference, Cambridge, UK, 2, 1–20, 1997.

10.

Yarlagadda

PKDV

Hock

. T.S., Statistical analysis on accuracy of wax patterns used in investment casting process. J Mater Process Tech 2003; 138: 75–81.

11.

Bonilla

Masood

Iovenitti

. An investigation of wax patterns for accuracy improvement in investment cast parts. Int J Adv Manuf Tech 2001; 18: 348–356.

12.

Dobrzanski

Domagala

Silva

. Application of Taguchi method in the optimization of filament winding of thermoplastic composites. Int Sci J 2007; 28(3): 133–140.

13.

Sharma

Verma

Sidhu

. Process parameter selection for strontium ferrite sintered magnets using Taguchi L9 orthogonal design. J Mater Process Tech 2005; 168: 147–151.

14.

Syrcos

. Die casting process optimization using Taguchi methods. J Mater Process Tech 2003; 135: 68–74.

15.

Fisher

. Statistical method for research worker , London: Oliver & Boyd, 1925.

16.

Ross

. Taguchi techniques for quality engineering, loss function, orthogonal experiments, parameter and tolerance design , New York: McGraw-Hill Inc., 1988.