Advances in Powder and Ceramic Materials Science: Ceramic-based Composites
Sponsored by: TMS Extraction and Processing Division, TMS Materials Processing and Manufacturing Division, TMS: Materials Characterization Committee, TMS: Powder Materials Committee
Program Organizers: Bowen Li, Michigan Technological University; Shefford Baker, Cornell; Huazhang Zhai, Beijing Institute of Technology; Kathy Lu, University of Alabama Birmingham; Rajiv Soman, Eurofins EAG Materials Science LLC; Faqin Dong, Southwest University of Science and Technology; Jinhong Li, China University of Geosciences (Beijing); Ruigang Wang, Michigan State University; Eugene Olevsky, San Diego State University
Tuesday 2:00 PM
March 16, 2021
Room: RM 37
Location: TMS2021 Virtual
Session Chair: Dipankar Ghosh, Old Dominion University
2:00 PM
Low-cost Forming and Reactive Melt Infiltration Processing of High-temperature, Thermally-cyclable Carbide/Metal Composites in Complex, Near Net Shapes for Renewable Energy Applications: Yujie Wang1; Priyatham Tumurugoti1; Zhenhui Chen1; Alex Strayer1; Adam Caldwell1; Saeed Bagherzadeh1; Grigorios Itskos1; Kevin Trumble1; Mario Caccia1; Kenneth Sandhage1; 1Purdue University
Certain co-continuous (interpenetrating) carbide/metal composites can exhibit attractive combinations of high-temperature properties, including higher erosion resistance, stiffness, and creep resistance than many metals, and higher toughness and thermal conductivity than many ceramics. In this talk, the near net-shape fabrication of thermal-expansion-matched (thermally-cyclable) ZrC/W composites will be discussed. The forming (e.g., tape casting, pressing, 3-D printing) of WC/organic mixtures, followed by organic pyrolysis and initial stage sintering (for WC particle necking), has provided porous, rigid WC bodies (“preforms”) with desired 3-D shapes and surface features. Such porous preforms have then been converted into near net-shaped ZrC/W composites (<1% dimension changes) via pressureless infiltration, and displacement reaction, with a Zr-bearing liquid. The increase in internal solid volume, upon WC conversion into ZrC and W, has resulted in solid filling of prior pores to yield dense ZrC/W composite bodies. The use of ZrC/W and related composites for renewable energy production will be discussed.
2:20 PM
Diamond Graphitization and Its Effect on Hardness of Diamond Particulate Ceramic Composites: Jerry Lasalvia1; Anthony DiGiovanni1; Kristopher Behler1; William Shoulders1; Scott Walck1; 1CCDC Army Research Laboratory
Diamond-ceramic composites fabricated by low pressure/high temperature methods are attractive materials due to their high values for stiffness, hardness, and thermal conductivity coupled with the potential for large sizes and complex shapes. One challenge to optimizing their properties is minimizing diamond graphitization. In this study, we examined the effects of hot-pressing temperature and time on the graphitization of diamond particulates in a monomodal diamond-SiB6 composite. Diamond-SiB6 powder mixtures with a diamond content of 25 vol% were hot-pressed between 1600oC-1700oC for 60-120 mins under flowing high-purity Ar and 48 MPa. In addition to determining densities, phases, and microstructures, we used Raman and scanning/transmission electron microscopy to characterize the diamond/ceramic interface and estimate graphite interlayer thicknesses. The effects of graphite interlayer thickness on hardness was determined by measuring variations in hardness with hot-pressing parameters. These findings and experimental procedures will be discussed.
2:40 PM
Bulk High-entropy Nitrides and Carbonitrides: Olivia Dippo1; Neda Mesgarzadeh1; Tyler Harrington1; Grant Schrader1; Kenneth Vecchio1; 1University of California San Diego
High-entropy ceramics have potential to improve the mechanical properties and high-temperature stability over traditional ceramics, and high entropy nitrides and carbonitrides (HENs and HECNs) are particularly attractive for high temperature and high hardness applications. The first synthesis of 5 bulk HENs and 4 bulk HECNs forming single-phase materials is reported herein among 11 samples prepared. The hardness of HENs and HECNs increased by an average of 22% and 39%, respectively, over the rule-of-mixtures average of their binary carbide and nitride precursors. Similarly, elastic modulus values increased by an average of 17% in nitrides and 31% in carbonitrides over their rule-of-mixtures values. The enhancement in mechanical properties is tied to an increase in the configurational entropy and a decrease in the valence electron concentration, providing parameters for tuning mechanical properties of high-entropy ceramics.