Surface roughness and dimensional tolerances in A319 alloy samples produced by rapid investment casting process based on fused filament fabrication

This paper aimed to investigate the effect of shape factor, slurry layers and pouring temperature in precision investment casting. Three controllable factors of the precision investment casting process (namely: shape factor, slurry layers (mold thickness) and pouring temperature) were studied at three levels each by Taguchis parametric approach and single-response optimization was conducted to identify the main factors controlling surface hardness, dimensional accuracy (Δd) and surface roughness (Ra). Castings were produced using aluminum (Al), mild steel (M.S.) and stainless steel (S.S) at recommended parameters through ceramic shell precision investment casting process. The micro structure analysis has been used to study the surface morphology. Analysis shows that for surface hardness, contribution of shape factor, slurry layers and pouring temperature is 0.07%, 0.70% and 99% respectively. As regards to surface roughness, contribution of shape factor, slurry layers and pouring temperature is 1.14%, 16.80% and 81.90% respectively. Further for Δd contribution of shape factor, slurry layers and pouring temperature is 1.53%, 22.47% and 72.88% respectively. Confirmation experiments were conducted at an optimal condition showed that the surface hardness, Δd and Ra of the precision investment casting were improved significantly.

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Electropolishing of Orthodontic Bracket Produced by Investment Casting Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.842.397 ◽

2016 ◽

Vol 842 ◽

pp. 397-401 ◽

Cited By ~ 2

Author(s):

Sugeng Supriadi ◽

Tito W. Sitanggang ◽

Bambang Irawan ◽

Bambang Suharno ◽

Tjokro Prasetyadi ◽

...

Keyword(s):

Surface Roughness ◽

Investment Casting ◽

Casting Process ◽

Orthodontic Brackets ◽

Metal Injection Molding ◽

Tooth Decay ◽

Orthodontic Bracket ◽

Difficulty Breathing ◽

Common Technique ◽

Investment Casting Process

Malocclusion or improper teeth arrangement is the most common problem in the field of orthodontics. If the malocclusion is not corrected, it will promote more serious problems, such as bleeding gums, tooth decay, cavities, difficulty breathing and other problems. Currently, the most common technique used to cure the malocclusion is using treatment of orthodontic brackets. Normally, orthodontic brackets can be produced by machining, metal injection molding and investment casting processes. In the previous research, orthodontic brackets have been successfully produced using investment casting process. The investment casting is selected, since the technology was developed well in Indonesia which is shown by existing number of investment casting industries. However, surface roughness of the bracket produced by investment casting is still high, valued at 0.91 μm. On the other hand, surface roughness of the commercial orthodontic bracket is 0.53 μm. In this current work is focused on surface modification of investment casting brackets by using electropolishing. The best result shows that the surface roughness of cast brackets achieve up to 0.44 μm. It shows that opportunity to fabricate orthodontic brackets domestically is applicable.

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