Influence of irradiation parameters on the polymerization of ceramic reactive suspensions for stereolithography

Stereolithography is an additive manufacturing process which makes it possible to fabricate useful complex 3D ceramic parts, with a high dimensional resolution and a good surface finish. Stereolithography is based on the selective UV polymerization of a reactive system consisting in a dispersion of ceramic particles in a curable monomer/oligomer resin. In order to reach a homogeneous polymerization in the green part, and to limit the risk of cracking and/or deformation during subsequent stages of debinding and sintering due to internal stresses, the influence of various fabrication parameters (laser power, scanning speed, number of irradiations) on the degree of polymerization was investigated. In addition, the impact of the irradiation of the subsequent upper layers onto the previously deposited and irradiated layers was evaluated. The degree of conversion was determined by Fourier Transform Infrared Spectroscopy (FTIR). Raman spectroscopy was also used and a brief comparison between these two methods is given.

[1]  S. Khalil,et al.  Use of FT-Raman Spectroscopy to Determine the Degree of Polymerization of Dental Composite Resin Cured with a New Light Source , 2007, European journal of dentistry.

[2]  T. Chartier,et al.  Stereolithography process: Influence of the rheology of silica suspensions and of the medium on polymerization kinetics – Cured depth and width , 2012 .

[3]  P. Bourson,et al.  In situ monitoring of styrene polymerization using Raman spectroscopy. Multi‐scale approach of homogeneous and heterogeneous polymerization processes , 2013 .

[4]  X. Allonas,et al.  Confocal Raman microscopy study of several factors known to influence the oxygen inhibition of acrylate photopolymerization under LED , 2016 .

[5]  Paul F. Jacobs,et al.  Rapid Prototyping & Manufacturing: Fundamentals of Stereolithography , 1992 .

[6]  J. Halloran,et al.  Photopolymerization of powder suspensions for shaping ceramics , 2011 .

[7]  J. Halloran,et al.  Depth and width of cured lines in photopolymerizable ceramic suspensions , 2013 .

[8]  John W. Halloran,et al.  Stereolithography of ceramic suspensions , 1997 .

[9]  Nicolas Delhote,et al.  Additive Manufacturing to Produce Complex 3D Ceramic Parts , 2014 .

[10]  Thierry Chartier,et al.  Ceramic suspensions suitable for stereolithography , 1998 .

[11]  Tom Scherzer,et al.  Real-time FTIR–ATR spectroscopy to study the kinetics of ultrafast photopolymerization reactions induced by monochromatic UV light , 1999 .

[12]  Jean-Pierre Kruth,et al.  Additive manufacturing of ceramics: A review , 2014 .

[13]  Paolo Colombo,et al.  Additive Manufacturing of Ceramics: Issues, Potentialities, and Opportunities , 2015 .

[14]  Alfonso Maffezzoli,et al.  Effect of irradiation intensity on the isothermal photopolymerization kinetics of acrylic resins for stereolithography , 1998 .

[15]  I. R. Lewis,et al.  Applications of Raman spectroscopy to the study of polymers and polymerization processes , 1993 .

[16]  Thierry Chartier,et al.  Rapid Prototyping of Ceramics , 2013 .

[17]  J. Halloran,et al.  Photopolymerization monitoring of ceramic stereolithography resins by FTIR methods , 2005 .

[18]  Thierry Chartier,et al.  Photopolymerization kinetics of a polyether acrylate in the presence of ceramic fillers used in stereolithography , 2011 .

[19]  John W. Halloran,et al.  Influence of Residual Monomer on Cracking in Ceramics Fabricated by Stereolithography , 2011 .