Manufacturing and Processing of Advanced Ceramic Materials: New Opportunities in Ceramic Processing I
Sponsored by: ACerS Manufacturing Division
Program Organizers: Bai Cui, University of Nebraska Lincoln; Mike Alexander, Allied Mineral Products, Inc.; Eric Faierson, Quad City Manufacturing Laboratory - Western Illinois University; James Hemrick, Oak Ridge National Laboratory; Keith DeCarlo, Blasch Precision Ceramics
Tuesday 2:00 PM
November 3, 2020
Room: Virtual Meeting Room 18
Location: MS&T Virtual
Session Chair: Michael Bakas, Army Research Office; Bill Fahrenholtz, Missouri University of Science and Technology
2:00 PM Invited
Identifying Multidisciplinary Research Opportunities in Ceramic Processing: Michael Bakas1; 1Army Research Office
Multidisciplinary research can drive new breakthroughs and open up new fields of study, but identifying opportunities can be challenging. The commonly employed single investigator grants have technical and practical barriers that inhibit collaboration with other scientific disciplines. As a result, researchers often feel compelled to address by themselves technical challenges that might benefit from the insight of another discipline. As program manager for the Army Research Office's Synthesis and Processing Program, Dr. Bakas has been involved in the writing of three topics for the DoD Multidisciplinary University Research Initiative Program that have direct relevance to ceramic processing. Using the MURI topics as examples, Dr. Bakas will discuss ways to recognize potential multidisciplinary projects, expected obstacles to their development, and best practices for refining the concept into a well-defined research project with clear goals.
2:40 PM Invited
Fusion Welding of Structural Ceramics: William Fahrenholtz1; Greg Hilmas1; Jeremy Watts1; 1Missouri University of Science and Technology
This presentation will describe the fusion welding of boride and carbide based structural ceramics. Methods including plasma arc welding and gas tungsten arc welding have been developed in our laboratory for joining transition metal boride and carbide ultra-high temperature ceramics, which are amenable to fusion welding methods based on their intrinsic thermal and electrical conductivities. Welding is performed in a controlled atmosphere with low oxygen partial pressure to prevent oxidation of the welded parts. Butt welds are produced by preheating specimens to ~1500°C to mitigate thermal shock issues. Welding parameters including current, translation speed, and gas flow rates can be optimized using statistical methods to produce high quality welds. Weld microstructure development is affected by specimen composition and heating parameters and must be controlled to produce joints with acceptable mechanical behavior. Examples of welding of several ceramic compositions will be discussed.
3:20 PM Invited
Indirect Additive Manufacturing of Ceramics: David Bourell1; 1University of Texas
While recent strides have been achieved lately in the production of ceramics using additive manufacturing (AM) methods, avoiding in-process cracking remains a challenge. An alternative approach is to indirectly process the ceramic parts by using a transient binder. This presentation will cover a short history of the development of indirect ceramic processing methods. Specific research will focus on creation of reaction-bonded silicon carbide using powder bed fusion and post-processing infiltration with silicon. The process will be described. Metrology issues by processing step are presented. A second example presented is graphite powder infiltrated with cyanoacrylate (“Super Glue”).
4:00 PM
Laser Shock Processing of Silicon Carbide Ceramics: Fei Wang1; Xueliang Yan1; Chenfei Zhang1; Leimin Deng1; Yongfeng Lu1; Michael Nastasi1; Bai Cui1; 1University of Nebraska-Lincoln
Laser shock processing (LSP) is a novel advanced manufacturing technique that utilizes a nanosecond pulse laser to generate plasma-driven shock waves, which can induce a high compressive residual stress to a depth of about 1 mm from the surface. Compared to metals, the application of LSP to ceramic materials is limited and the associated mechanisms are poorly understood. Our research has reveal the fundamental mechanisms underlying the microstructural changes and mechanical properties in ceramic materials (such as α-SiC) in the LSP process. TEM characterizations revealed significant dislocation activities near the surface and grain boundaries, suggesting that the localized plastic deformation was generated by LSP at room temperature. X-ray diffraction analysis showed that the compressive residual stress can extend from the surface to a depth of 750 µm. The LSP-induced localized plasticity can improve the mechanical properties of SiC ceramics, such as the apparent fracture toughness and bending strength.