T.R. Vijayaram
- Assistant Professor, Department of Mechanical Engineering, School of Mechanical Engineering, BIST, BIHER, Bharath University, Selaiyur, Chennai, Tamil Nadu, India
Abstract
Sand molding is a versatile casting process that provides freedom of design with respect to size, shape, and product quality. Plaster casting is similar to sand molding process except that a plaster is substituted instead of sand. Plaster compound is composed of gypsum, which strengthens the mould. Parts made by this process are gears, valves, fittings, tooling, and ornaments. The finished product of plaster casting has a very high surface finish and fine tolerances can be attained. Gypsum in the plaster will slowly reacts with the iron and the maximum temperature of plaster casting is limited to 1200 degree centigrade, which limits the material to be cast by using this method. A thin layer of parting film is usually sprayed to the pattern to prevent mold from sticking the pattern, and this step is a necessary one. In this method, the mold box is shaked to allow the filling of the sand in the cavities around the pattern, and it is then dried at the temperature between 120 degree centigrade to 260 degree centigrade. In this research work, a simple shape of anvil is used as the mould cavity when performing sand casting process. The molten metal used is tin and tin castings are processed. The effect of gypsum addition in moulding sand is studied and surface finish of the casting is revealed and observed before and after gypsum addition. Besides, microstructure of casting is analyzed after and before addition of gypsum in the moulding sand.
Keywords: Gypsum, moulding sand, green sand moulding, surface defects, surface finish
[This article belongs to International Journal of Fracture Mechanics and Damage Science(ijfmds)]
Browse Figures
References
- Donohue, T.L. & Dr.Frye, H.F, “Characterization and Correction of Casting Defects”. TechForm – Advanced Casting Technology, L.L.C., pp. 1-22, 1999.
- P L Jain, “Principle of foundry technology, fourth edition” India: Tata-McGraw-Hill., 2003.
- Ravi, Available at http://www.energymanagertraining.com/foundries/pdf/ CDA1.pdf (Date accessed: 23 august 2008), 2008.
- Ravins, T., Greve, D, “Fiber Reinforced Plaster Molds for Metal Casting”. U. S. Pat. US4818287, 1989.
- Serope Kalpakjian, Steven Schmid, “Manufacturing Engineering and Technology.” Singapore: Prentice Hall, pp. 275-277, 2006.
- Wolfe, Mary, “Tips for auditing your green sand system” Modern casting, 1999.
- Granlund MJ. Understanding the basics of green sand testing. Modern Casting(USA). 1999 Mar;89(3):38-40.
- Lankard DR, Hedden WA, inventors; Pmcma Research Group, assignee. Plaster molding composition. United States patent US 4,148,660. 1979 Apr 10.
- Boumaaza M, Belaadi A, Bourchak M. The effect of alkaline treatment on mechanical performance of natural fibers-reinforced plaster: Part II optimization comparison between ANN and RSM statistics. Journal of Natural Fibers. 2022 Oct 28;19(14):8367-82.
- Khorasani FF, Kabir MZ. Experimental study on the effectiveness of short fiber reinforced clay mortars and plasters on the mechanical behavior of adobe masonry walls. Case Studies in Construction Materials. 2022 Jun 1;16:e00918.
| Volume | 01 |
| Issue | 02 |
| Received | April 1, 2024 |
| Accepted | April 8, 2024 |
| Published | April 25, 2024 |