Structure-Property Relationship of Binder Jetted Fused Silica Preforms to Manufacture Ceramic-Metallic Interpenetrating Phase Composites by Kyle Myers Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Materials Science and Engineering Program YOUNGSTOWN STATE UNIVERSITY May, 2016 Structure-Property Relationship of Binder Jetted Fused Silica Preforms to Manufacture Ceramic-Metallic Interpenetrating Phase Composites Kyle Myers I hereby release this dissertation to the public. I understand that this dissertation will be made available from the OhioLINK ETD Center and the Maag Library Circulation Desk for public access. I also authorize the University or other individuals to make copies of this thesis as needed for scholarly research. Signature: Kyle Myers, Student Date Approvals: Dr. Pedro Cortes, Dissertation Advisor Date Dr. Brett Conner, Committee Member Date Dr. Tim Wagner, Committee Member Date Dr. Donald Priour, Committee Member Date Brian Hetzel, Committee Member Date Dr. Salvatore A. Sanders, Dean of Graduate Studies Date ABSTRACT Additive manufacturing (AM) is an area of high interest due to its rapid prototyping and high complexity abilities. Powder based AM techniques allow for a wide variety of materials to be studied. Here, the binder jetting of fused silica (SiO2) powders were investigated as precursor materials for subsequent molten metal infiltration and the manufacturing of metal-ceramic interpenetrating phase composites (IPCs). The structure- property relationship of cured, sintered, and infiltrated states were correlated to the variables powder size, spread speed, binder saturation, layer thickness, and sintering temperature. The process parameters of the X1-Lab printer were optimized to manufacture the strongest SiO2 ceramic body with the highest density. The printed parts were subsequently infiltrated with molten aluminum to create unique Al/Al2O3 IPCs. The parameters of 48 μm powders, 0.5 mm/sec spread speed, 60% binder saturation, 100 μm layer thickness, and 1500°C sintering temperature resulted in the highest density and compression strength of both the sintered and composite states. It was also found, that the mechanical investigation of the composite materials exhibited a strain-rate dependency that was observed by the split Hopkinson testing. In addition to the aforementioned outcomes, it was found that further densification of the printed parts is required to achieve the full potential of additive manufacturing on synthesizing IPCs for structural applications. A homogenization technique was also carried out via Matlab, and it showed to be a quick and reliable simulation technique to predict the elastic modulus of a two- phase composite system. Finally, alternative processing techniques were explored to create dense printed and infiltrated parts. It was shown that the agglomeration of small iii particles and the addition of external pressure during the infiltration stage appear to be promising routes for increasing the density of IPCs manufactured via binder jetting. iv Acknowledgements I would first like to thank my dissertation advisor Dr. Pedro Cortes. Without your mentorship and guidance, I would not be where I am today. Thanks for everything Dr. Cortes. I would like to thank my committee members Dr. Brett Conner, Dr. Tim Wagner, and Dr. Donald Priour. Thanks for the opportunity and knowledge to fulfil and exceed the requirements for this degree. I would also like to Mark Peters, Brian Hetzel, Walt Whitman, and Eddie Stride thank Fireline Inc. Brian, you have been a great role model and friend. All of the graduate students at Youngstown State that I have met through my four years here. I am truly thankful for our long lasting friendship and memories, as well as the beers at Inner Circle. Cheers. Lastly, I would like to thank my family and wonderful girlfriend Traci. Thanks for all the love and support. I love you all. v Table of Contents Title Page ................................................................................................................................. i Abstract ................................................................................................................................... iii Acknowledgements ..................................................................................................................v Table of Contents .................................................................................................................... vi List of Figures ......................................................................................................................... ix List of Tables ......................................................................................................................... xii Chapter 1 Introduction..........................................................................................................1 Chapter 2 Literature Review ...............................................................................................15 2.1 Ceramics ...........................................................................................................................15 2.1.1 Crystal Structures ...........................................................................................................16 2.1.2 Mechanical Properties ....................................................................................................21 2.1.3 Manufacturing Techniques ............................................................................................22 2.1.3.1 Casting ........................................................................................................................23 2.1.3.2 Forming .......................................................................................................................24 2.1.3.3 Pressing .......................................................................................................................26 2.2 Metals ................................................................................................................................28 2.2.1 Mechanical Properties ....................................................................................................30 2.2.2 Manufacturing Techniques ............................................................................................33 2.2.2.1 Casting ........................................................................................................................33 2.2.2.2 Deformation ................................................................................................................35 2.2.2.3 Subtraction ..................................................................................................................36 2.3 Composites ........................................................................................................................38 2.4 Ceramic-Metallic Composites ..........................................................................................40 2.4.1 Manufacturing Techniques ............................................................................................41 2.4.2 Reactive Metal Penetration ............................................................................................46 2.4.3 Applications ...................................................................................................................51 2.4.3.1 Ballistics ......................................................................................................................52 2.4.3.2 Automotive and Aerospace .........................................................................................55 2.4.4 Mechanical Property Characterization ...........................................................................58 2.5 Additive Manufacturing ....................................................................................................63 2.5.1 Computer Assisted Design (CAD).................................................................................64 2.5.2 Vat Polymerization ........................................................................................................66 2.5.3 Sheet Lamination ...........................................................................................................68 2.5.4 Powder Bed Fusion ........................................................................................................70 2.5.5 Material Extrusion .........................................................................................................73 2.5.6 Directed Energy Deposition ...........................................................................................75 2.5.7 Binder Jetting .................................................................................................................77 2.5.7.1 Introduction .................................................................................................................77 2.5.7.2 Process Parameters......................................................................................................80 2.5.7.3 Infiltration of Printed Ceramic Structures ...................................................................85 vi Chapter 3 Experimental ......................................................................................................118 3.1 Binder Jetting of Ceramic Precursors ..............................................................................118 3.1.1 Powder Feeding Systems ..............................................................................................119