Effects of the polymeric binder system in slurry-based three dimensional printing of ceramics

The factors dictating the minimum feature size in Slurry-based Three Dimensional Printing (S-3DPTM) of ceramics have been examined, focusing on effects related to the polymeric binder system polyacrylic acid (PAA, MW 60000) and its interaction with the ceramic powder bed. Methods for retrieving structures characteristic of the minimum feature, referred to as the "binder primitive," and for characterizing the size and shape of the binder primitive have been developed. Impact-related spreading of the printed binder droplets has been found to play little or no role on the primitive structure. Two dominant factors controlling primitive width were however identified. The first is wetting-induced spreading of the printed binder solution on the surface of the powder bed. The spreading process is halted prior to completion by infiltration of the printed liquid into the pore space. The role this factor plays thus depends on wetting properties and the relative rates of spreading and infiltration. The spreading and infiltration rates were modeled, and a means of predicting the maximum extent of spreading was developed. The second factor controlling minimum feature size is adsorption of the polymeric binder molecules from solution onto the surface of the ceramic particles during infiltration of the printed binder solution. This effectively filters the polymer from solution, resulting in a progressive decrease in concentration as the binder solution penetrates deeper into the pore space of the powder bed, which serves to limit the primitive size.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Holman Richard K. (Richard Kimbrough), 1973-

Advisor dc:contributor.advisor

• Michael J. Cima.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8448

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8448