Debinding Rate Enhancement of 17-4 Precipitation Hardening Stainless Steel Solvent Debinding on Metal Injection Molding Process as the Material for Orthodontic Bracket

Abstract

Brackets fabrication should be done by a suitable process to produce great result. Processes commonly used are investment casting, machining, and metal injection molding. Investment Casting has a drawback in which the surface roughness is quite high for the standard of brackets and require further processing. Machining is done by removing unwanted part to get desire shape, whereas bracket shape requires a high accuracy and is quite complicated. In Metal Injection Molding, feedstock is injected into a mold where complicated shapes can be achieved with a better surface roughness. The weakness is the stages within the process are quite long. One of the problem is the efficiency of debinding stage. We conducted an experiment to enhance binder removal rate through solvent debinding with stirring and under vacuum condition. Sample use for this experiment is a cubic shape of 0.5 x 0.5 x 0.5 cm3. Experiment is done on magnetic stirrer and in vacuum furnace. The temperature is hold at 50°C. Drying process afterward is done in the vacuum furnace for 1 hour with temperature around 50°C. Amount of binder left is confirmed by STA and the particle morphology is seen by SEM. Results showed that stirring treatment enhances binder removal rate due to stirring mechanism that causes possibility of collisions between particles increases. Binder removal rate on the vacuum treatment has a mechanism similar to stirring, but with the addition of the solvent to be done on a regular basis due to decrease of solvent boiling point under vacuum. There were no cracks found on the surface with an increased rate of debinding. Stirring is use for experiment with sample of actual bracketorthodontic form. Debinding rate of the bracket sample is faster than the cubic sample. This result is affected by the dissimilarity on the volume to surface area.

Formation of TiO₂ Thin Film on Antibacterial Metal Injection Molding Stainless Steel Orthodontic Bracket 17-4 PH Using Physical Vapor Deposition Method

“…Stainless steel 17-4 PH orthodontic brackets fabricated using MIM of following chemical composition in wt.% (Fe-base, Ni -5 %; Cr -17,5 %; C -0,07 %; Cu -5,0 %; Nb+Ta -0,45 %) were used to conduct the research. They were manufactured according to the parameters described in past studies [10,11]. Electropolishing was performed to prepare sample before TiO2 is applied on the surface as described in previous research [12].…”

Designs and Evaluations of a Gas Atomizer to Fabricate Stainless Steel Metal Powder to Be Applied at a Metal Injection Molding

“…One of the best methods to produce highly precise small components to be used in mass productions is Metal Injection Molding (MIM). A MIM process can produce complicatedly-shaped small size products with a better surface roughness, a high geometric accuracy and less porosity than that of investment casting [2][3][4]. MIM is an application of Powder Metallurgy (PM) combined with Plastic Injection Molding (PIM) [1,[5][6][7].…”

Effect of Pressure on the Gas Atomizer to Fabricate Stainless Steel Metal Powder

“…Its oxidative resistance to metal processing through the PM method makes this alloy widely used in industry, medical equipment, automotive elements, and chemical equipment [1]. The PM processes that are now being developed include Metal Injection Molding (MIM), which can produce complex shaped products with high geometric accuracy and better surface roughness than investment casting [2,3]. The MIM process can produce products with less porosity compared than investment casting [4].…”