Advanced Materials for Harsh Environments: Session IV
Sponsored by: ACerS Electronics Division
Program Organizers: Navin Manjooran, Solve; Gary Pickrell, Virginia Tech
Wednesday 8:00 AM
October 12, 2022
Room: 334
Location: David L. Lawrence Convention Center
Session Chair: Navin Manjooran, Chairman, Solve; Gary Pickrell, Virginia Tech
8:00 AM Presentation Planned
8:40 AM
Utilization of Acacia senegal for Rubber Processing Effluent Treatment: pH Variations and Optimum Dose determination: O. C Ize-Iyamu1; Ikhazuagbe Ifijen1; E.E Ukpebor1; O.K Ize-Iyamu2; I.O. Bakare,1; A.O Ohifuemen1; N.U Udokpoh,1; F.U Mohammed,1; E.A Fagbemi,1; 1Rubber Research Institute of Nigeria; 2 Ambrose Alli University, Ekpoma
The investigation of the effect of pH change and optimum dose on the efficacy of Acacia senegal as a coagulant for rubber processing effluent treatment via coagulation and flocculation method was carried out. Jar test experiments were carried out with effective monitoring of the COD levels with the corresponding %COD reduction of the effluent with change in pH levels. The optimum dose of AS was also determined at the effective pH range per 100mL of the rubber processing effluent sample. The findings in this study revealed that Acacia senegal is pH-dependent as a coagulant. The highest %COD reduction recorded was 87.75 % at pH 8.3, which is alkaline with an optimum dose of 3.2g/100ml of the effluent sample. This paper suggests an adherence to the required pH for the coagulative potentials of Acacia senegal to be maximally exploited.
9:00 AM
CMAS Interaction with Model YAlO3 Environmental Barrier Coatings: Effect of Y3Al5O12 Precipitation on Apatite Nucleation and Growth: Amanda Velazquez Plaza1; Amanda Krause1; 1University of Florida
Alumina ceramic-matrix composite parts allow higher operating temperatures and lighter parts, improving the efficiency of gas turbine engines. In engine environments, alumina reacts with steam and volatilizes, requiring environmental barrier coatings (EBC) for protection. However, interaction with molten ingested aluminosilicates (CMAS) can lead to coating corrosion or grain boundary infiltration, resulting in failure. In this study, we examine the nucleation and growth mechanisms of reaction products formed from CMAS attack on single crystals of EBC candidate YAlO3 (YAP): Y3Al5O12 (YAG) and Ca4Y6(SiO4)6O (apatite). We characterized the microstructural evolution of the CMAS interaction region at 1350°C on multiple YAP substrate orientations. Varying YAP orientations led to dissimilar CMAS loading conditions and degrees of apatite coarsening. By correlating the CMAS-blocking ability with the nucleation and growth of the reaction products on different YAP crystallographic planes, we can move towards engineering a coating that favors desirable CMAS-mitigating products.
9:20 AM
Far-Field Passive Wireless Sensors using Conductive Ceramic for High-Temperature Health Monitoring: Kevin Tennant1; Edward Sabolsky1; Jay Wilhelm2; Brian Jordan1; Kavin Sivanerai1; 1West Virginia University; 2Ohio University
Temperature and health sensing is an important aspect that is required by all industries to closely monitor and prevent equipment failures and process inefficiencies. Sensors in these environments can be limited by a power source or other various conditions that can affect the material properties of conducting and resonating elements. Electroceramic materials possess some properties such as, chemical stability, high electrical conductivity and thermal protective layer that may be of interest for a passive wireless sensing unit. This work focuses on the investigation and development of far-field passive wireless sensors using electro ceramics that resonate below 4 GHz. The sensor design was modeled via Ansys HFSS and experimentally evaluated to obtain the resonant frequency, signal strength and thermomechanical properties of the system assessed under low and high temperature variations.
9:40 AM
High Temperature Thick Film Sensor Development Based on Doped Lanthanum Chromites Refractory Semiconductors Materials: Javier Mena1; Edward Sabolsky1; Konstantinos Sierros1; Katarzyna Sabolsky1; Domenic Cipollone1; Víctor Mendoza2; Anthony Abrahamian1; 1West Virginia University; 2Universidad del Norte
Solid-state high-temperature sensing devices are required for accurate temperature monitoring for a range of advanced manufacturing, transportation, and military applications. High-temperature conditions limit sensing strategies, where typically metal and semiconductor materials are unstable. In addition, strategies to embed the sensors directly within active components and protective refractory are of interest that permit sensing which is not possible with traditional electronic materials. Rare earth chromites semiconductors exhibit some properties of interest for high temperature sensing technologies, such as: chemical stability, high electronic conductivity at high temperatures, and thermal expansion coefficient match to thermal protective insulation. In this work various doped lanthanum chromites were prepared, the electrical, thermoelectric, and thermomechanical properties were modelled and experimentally measured for the obtained systems. Compositions were then processed into thick film and temperature sensors and tested at high temperatures. To stablish stability under harsh conditions, post-mortem microstructure and chemical composition was characterized after extended testing cycles.
10:00 AM Break
10:20 AM
The Effect of Residual Stress on Aluminum Pitting Corrosion: Junyeop Lee1; Eunkyung Lee1; 1National Korea Maritime and Ocean University
The anisotropic corrosion behavior of aluminum was investigated under the applied residual stress state with elastic and plastic deformations. Under the initiation stage in the electrochemical response of aluminum with the residual stress, grain orientations play a crucial role in nucleating pits, with an impact on work function. However, in the propagation stage, a clear correlation between the residual stress, work function, and the corrosion rate is demonstrated. The differences in the corrosion rate of grains are attributed to the residual stress concentration and sensitivity, which are resulting from the mechanical properties of each grain. With the residual stress concentration and grain properties, grains close to (111) with higher work function corroded faster, in contrast, grains close to (100) with low work function have a slower corrosion rate. Work function calculated based on coordination numbers and first-principle calculations performed, and correspond to each other, with support the experimental results observed.
10:40 AM
An Investigation of High Temperature Corrosion Sensing for Coal-based Power Plant Operations: Brian Jordan1; Edward Sabolsky1; Daryl Reynolds1; Kavin Sivaneri1; Kevin Tennant1; Derek Hockenberry1; 1West Virginia University
The work focussed upon the development of wireless high temperature sensors for monitoring the temperature and corrosion of metal components commonly used in coal-fired boilers. The sensor architecture was based on capacitance change of the material with a dielectric barrier layer between the metal and ceramic. The sensors design included thick film refractory metal and/or electrically conductive components pattered over a base ceramic/glass dielectric layer. These sensors are either directly deposited onto, or transferred over, common boiler metals, such as stainless steel 304H. Various wireless sensor interrogation methods and signal processing methods were investigated. The high-temperature corrosion behaviour of the stainless steel was characterized up to 800ºC in high steam conditions, and the corrosion kinetics were correlated to the wireless sensor response over this time. Post- mortem microstructural analysis after corrosion testing was completed on the coupons toinvestigate sensor stability and failure mechanisms.
11:00 AM Concluding Comments