Additive Manufacturing of High and Ultra-high Temperature Ceramics and Composites: Processing, Characterization and Testing: Composites and Reinforcements
Sponsored by: ACerS Young Professionals Network
Program Organizers: Corson Cramer, Oak Ridge National Laboratory; Lisa Rueschhoff, Air Force Research Laboratory; Greg Hilmas, Missouri University of Science and Technology
Wednesday 8:00 AM
October 12, 2022
Room: 306
Location: David L. Lawrence Convention Center
Session Chair: Austin Martin, Navy Research Lab
8:00 AM Invited
Additive Manufacturing of Chopped Fiber Ultra-High Temperature Ceramic Composites: James Kemp1; Benjamin Lam1; Connor Wyckoff1; William Costakis1; Lisa Rueschhoff1; 1Air Force Research Laboratory
Ultra-high temperature ceramics (UHTC) and their composites (UHTCMCs) are of interest for use in harsh environments encountered by next-generation Air Force systems. Still, they are limited by their ability to be processed into complex-shaped components. A solution is through additive manufacturing (AM) via direct ink writing (DIW), which allows for the complex shaping of ceramics and composites. To create complex ceramic shapes, shear-thinning, visco-elastic tailored inks are developed with aqueous slurries and are extruded layer-by-layer. Two sets of inks were developed, one set with zirconium diboride (ZrB2), an UHTC, and another with silicon carbide (SiC). Both sets of inks were loaded with varying amounts of chopped carbon fibers (Cf) as a reinforcing phase. This study includes an analysis of the rheology and printability of inks, the effects of printing parameters on final ceramic development, Cf alignment along the deposition direction, and characterization of the densified samples via pressureless sintering.
8:30 AM
AM of SiC:SiC Composites via Robocasting: John Stuecker1; Steve Bullock2; David Mitchell2; Tristin Anderson2; Hunter Berner1; Corson Cramer2; 1Robocasting Enterprises; 2Oak Ridge National Laboratories
Progress towards Additive Manufacturing (AM) of continuous-fiber reinforced SiC/SiC composites will be reviewed. The Department-of-Energy-funded project focuses on reducing the energy cost of manufacturing SiC/SiC composites utilizing AM and advanced Polymer Infiltration and Pyrolysis (PIP) for densification when compared to conventional hand-layup and Chemical Vapor Infiltration (CVI). Further energy costs will be realized when these SiC/SiC composites are implemented in the hot zone of turbine engines, allowing for higher combustion conditions and therefore more-efficient use of fuel. The AM method employed is an extrusion-deposition method (robocasting) that will allow for coextrusion of continuous fiber tows and a high-solids-loading matrix material. Aqueous carriers have been replaced with PreCeramic Polymers (PCPs) for a high-yield matrix material.
8:50 AM
Strategies for Printing Fibers and Post-processing for Ceramic Matrix Composites (CMCs): Corson Cramer1; David Mitchell1; James Klett1; Vlastimil Kunc1; 1Oak Ridge National Laboratory
Continuous and long, chopped carbon fibers are 3D printed with thermoplastics, and pyrolysis converts the fiber reinforced polymer to porous carbon fiber-reinforced carbon matrix. Samples were densified using three approaches: 1) melt infiltration (MI) of Si to create SiC by reacting with carbon matrix 2) chemical vapor infiltration (CVI) of SiC to make ceramic matrix composites (CMCs) and 3) polymer impregnation and pyrolysis (PIP). Results are shown from manufactured preforms, pyrolysis, infiltration, microstructure, and bend strength from samples made via fused filament fabrication (FFF), laminate 3D printing, and automatic fiber placement (AFP). The laminate 3D printing approach may have the ability to form more complex shapes versus continuous fiber FFF of AFP.
9:10 AM
Evaluating Extrusion Deposited Additively Manufactured Fiber-reinforced Thermoplastic Polymers as Carbon/Carbon Preforms: Edwin Romero1; Eduardo Barocio2; Rodney Trice1; 1Purdue University; 2The Composites Manufacturing and Simulation Center
Extrusion deposition additive manufacturing of thermoplastic polymers allows embedded fibers to be oriented locally and globally without the use of molds, enabling more control over fiber architectures, the matrix thermal history, and its microstructure. Carbon/carbon composite processing can benefit from extrusion deposition additive manufacturing but thermoplastic conversion to carbon results were needed. In this study, we analyzed several short carbon fiber-reinforced thermoplastic polymers with varying fiber contents, including polyphenylene sulfide, polyetherimide, poly sulfone, polyether sulfone, and polyether ether ketone via thermogravimetric analysis and carbonization tests to compare carbon yields and dimensional stabilities during pyrolysis. The results showed that conversion of short carbon fiber-reinforced polyphenylene sulfide into carbon/carbon composites was the most promising because of its dimensional stability. The carbonization results for an additively manufactured fiber-reinforced polyphenylene sulfide nozzle showed that slow heating rates could be used to perform shape- and size-preserving initial pyrolysis processing of more complex geometries.
9:30 AM
High-temperature Performance of LCVD SiC Fiber-Reinforced CMCs: Mark Schaefer1; Jeff Vervlied1; Kirk Williams1; Joseph Pegna1; 1Free Form Fibers
Free Form Fibers is a materials development company that specializes in the production of high-temperature materials by means of Laser-induced Chemical Vapor Deposition (LCVD), a container-less material-agnostic approach that deposits material directly from the gas phase. The LCVD approach can be seen as an additive manufacturing technique, growing material in "1 and 1/2 dimensions" (1.5 D). Silicon carbide fibers produced at Free Form Fibers (FFF) by LCVD have previously been discussed. This current project will study the performance of LCVD SiC fibers in fiber-reinforced composite structures. Test coupons were fabricated using FFF's AM-based LCVD fibers as a nonwoven preform as the reinforcement phase in a silicon nitride matrix. The flexural performance was tested at room temperature and at elevated temperatures of 2700 F. The creep, tensile, and inter laminar shear testing will be conducted, with the resulting thermal and mechanical behavior to be discussed.
9:50 AM Break
10:10 AM Invited
Considerations for Additive Manufacturing of Ultra-high Temperature Ceramic Composites Using Preceramic Polymers: Brett Compton1; 1University of Tennessee
Over the last several years, considerable progress has been made in additive manufacturing (AM) technologies and the materials available for such technologies. Material extrusion, in particular, provides unique opportunities for AM of composite materials with high solids loading, unique multi-scale architecture and fiber arrangement. This approach has been studied in some depth using thermoplastic and thermoset polymers, but there is growing interest in utilizing preceramic polymers with material extrusion to enable AM of ceramic composites. This talk will begin with a brief overview of material extrusion AM, followed by a discussion of features of the process that are relevant to controlling architecture and properties in printed composites. The talk will conclude with the discussion of a few examples of material extrusion AM of high- and ultra-high temperature ceramics using highly-loaded silicon carbide and silicon nitride precursor polymers. Additional challenges associated with pyrolysis of the preceramic polymers will also be discussed.
10:40 AM
Anisotropic Microstructures in Platelet-Seeded Silicon Carbide obtained via Direct Ink Writing: Tess Marconie1; Jeffrey Youngblood1; Rodney Trice1; 1Purdue University
Silicon carbide (SiC) is a material of interest for many applications due to its mechanical properties, oxidation resistance, and high thermal conductivity. Colloidal processing and pressureless sintering can enable forming of complex shaped, dense SiC parts. Direct ink writing (DIW) is a colloidal processing technique where ceramic suspensions are extruded through a nozzle along a path, building up a part layer-by-layer. However, DIW is not only interesting for making complex shapes, but also for creating anisotropic microstructures by aligning particles via the forces in the print nozzle. In this work, SiC with anisotropic microstructure is created via the alignment of platelet seed particles in DIW and subsequent pressureless liquid phase sintering and annealing. The anisotropic microstructure and crystallographic texture of these materials will be explored with SEM, XRD, and EBSD. Mechanical properties of these ceramics will be explored via 4-pt flexural strength with Weibull analysis performed.