Advanced Materials for Harsh Environments: Session II
Sponsored by: ACerS Electronics Division
Program Organizers: Navin Manjooran, Solve; Gary Pickrell, Virginia Tech
Tuesday 2:00 PM
October 19, 2021
Room: A223
Location: Greater Columbus Convention Center
Session Chair: Gary Pickrell, Professor, Virginia Tech; Navin Manjooran, Solve
2:00 PM Keynote
RF Radomes and IR Windows for Hypersonic Flight: Material Requirements and Development of Ceramic Processing Routes for Success: Rodney Trice1; Averyonna Kimery1; Ashwin Sivakumar1; Jeffrey Youngblood1; Carlos Martinez1; Andrew Schlup2; 1Purdue University; 2UES
While hypersonic aircraft have the same needs to receive and send electromagnetic signals for navigation and tracking as typical aircraft, the RF radomes and IR windows that protect antennae and/or sensors must survive the extreme aerothermal environment consistent with high-speed flight, including surface temperatures of 1500oC or greater. In this presentation, we discuss a review of the open literature on the material requirements for RF and IR transmission, microstructure requirements for each as a function of wavelength, along with our ongoing investigations fabricating porous silicon nitride for RF transmission and pore-free alumina for IR transmission.
2:30 PM
Novel Non-aqueous Gelcasting of UHTCs for Advanced Complex Shape Manufacturing: Julia Goyer1; Carolina Tallon1; 1Virginia Tech
Advanced manufacturing and complex shaping are paramount to widen applications of Ultra-High Temperature Ceramics (UHTCs) in extreme environments. Significant interest has been garnered in colloidal processing techniques that allow complex shaping and microstructural design to tailor properties. In this work, zirconium diboride (ZrB2) has been processed with a novel formulation for non-aqueous gelcasting. The HEMA-MBAM system was effective in organic solvents such as N,N-dimethylformamide (DMF) leading to concentrated stable suspensions with low viscosity with the addition of gelcasting monomers. DMF was selected after optimization of interparticle forces. The UHTC green samples produced with this system maintained sharp edges following demolding after only 30 minutes. The gelation time and other gel characteristics were studied using oscillatory rheology. The green samples were characterized in terms of density, microstructure and strength. These promising results open the door to new component geometries, architectures and microstructures for UHTC materials and other non-oxide ceramics.
2:50 PM
High Temperature Mixed Deposit and Oxidation Degradation of a Coated and Uncoated Ni-based Superalloys: Matthew Kovalchuk1; Brian Gleeson1; 1University of Pittsburgh
Gas-turbine engine degradation in the high-pressure section is traditionally associated with Na2SO4 deposit and, more recently, CaSO4 deposit. In practice, mixtures of sulfates and oxides comprise particulate matter commonly deposited on engine components. This presentation will systematically assess the degradation behavior of deposit mixtures on a Generation II Ni-based superalloy with and without a chromide coating. Prior work has shown alloy oxidation following deposit-induced degradation can lead to severe internal oxidation attack. Protective scale breakdown and subsurface changes due to mixed deposit degradation are analyzed in terms of subsequent oxidation behavior. Engine and environmental field variables such as water vapor and deposit loading are also discussed.
3:10 PM
Features of the Formation of the Structure and Properties of Corrosion-resistant Steel during Heat Treatment: Valeriy Mishchenko1; Olha Bolsun1; Svitlana Mudra1; Sergеy Sheyko1; 1Zaporizhzhia National University
The article shows the effect of multicomponent alloying of chromium-nickel steel 14Х16Н13МБ (Standard of Ukraine) on the hardening mechanism and short-term heat resistance of the material. Aerospace industry uses steels, which operates at high temperatures of 600 °C - 1000 °C and static and dynamic loads, for the manufacture of parts and assemblies of gas turbine engines (GTE).As a result of the work the effect of alloying with carbon, chromium, nickel, and other elements on hardening mechanisms, structure formation processes, and the basic principles of creating heat-resistant steel with increased working capacity was formulated. A rationally grounded content of alloying elements prevents the appearance of the δ-ferrite and σ-phase during prolonged operation of parts in the temperature range of 850 °C - 900 °C.