Controlling Microwave Energy Absorption in Aluminum Particle Compacts by Tuning the Crystallinity of the Alumina Shell
Year: 2026
Type: article
Abstract: Controlling the conversion of microwave energy to thermal energy within aluminum particle compacts was achieved by changing the phase of the alumina passivation shell. The alumina shell surrounding the aluminum core particle was altered by thermal processing in an air environment. The powder was annealed to 400°C and held for varied times of 30, 60, 90, and 120 minutes before returning to room temperature. Shell growth was measured from analysis of transition electron microscopy (TEM) images and increased from 2.5 nm to 9.6 nm. Moreover, the thermal treatment affected the crystallinity within the shell. X-ray Diffraction (XRD) analysis showed initially amorphous particle shells with small indications of crystallite inclusions. After thermal treatment, concentrations of stable- and meta-stable phases of alumina increased, and the quality of the crystalline structure increased with thermal treatment time. The compacts formed from these powders were exposed to microwaves at a frequency of 2.45 GHz for five minutes within an electromagnetic exposure chamber. As the compacts were subjected to microwaves, a FLIR infrared camera collected transient temperature data in-situ . Steady state temperatures were measurably higher for the as-received, untreated powder compacts. The phase transition to crystallinity induced a 25% decrease in steady state temperature upon microwave exposure. Results show that microwave heating is influenced by the phase of the alumina shell on aluminum particles and can be used as a control the material response to microwaves.
Institution: Texas Tech University
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,390
Awards: G2434112684, G7644570262, TEXAS TECH UNIVERSITY
TITLE:GROWING STEMS CONSORTIUM: TRAINING THE NEXT GENERATION OF ENGINEERS FOR THE DOE/NNSA WORKFORCE
PROJECT DESCRIPTION: THE GOAL IS TO PREPARE THE NEXT GENERATION OF ENGINEERS FOR THEIR INTEGRATION INTO THE DOE/NNSA ENTERPRISE. THE GOAL WILL BE ACCOMPLISHED BY CREATING A SUSTAINABLE PROGRAM DESIGNED TO RECRUIT, EDUCATE, INSPIRE, AND TRAIN A DIVERSE STUDENT POPULATION AND ASSIST THEIR TRANSITION FROM ACADEMIA INTO DOE/NNSA EMPLOYMENT THROUGH PROJECT RELEVANT EXPERIENCE-CENTERED COLLABORATIONS AND STUDENT TRAINING PIPELINES. THE PROGRAM IS CALLED THE GROWING STEMS CONSORTIUM (GSC). ). OUR TEAM INCLUDES FACULTY WITH EXPERTISE IN A DIVERSE RANGE OF ENGINEERING DISCIPLINES FROM TEXAS TECH UNIVERSITY (TTU) AND NEW MEXICO TECH (NMT) INCLUDING THE ENERGETIC MATERIALS RESEARCH & TESTING CENTER (EMRTC), AS WELL AS TECHNICAL EDUCATORS FROM AMARILLO COLLEGE THAT WILL FOCUS ON TRAINING GSC PARTICIPANTS FOR TECHNICIAN CERTIFICATIONS, AND AN ENGINEERING EDUCATION EXPERT FOR MINORITY STUDENT LEARNING FROM THE UNIVERSITY OF HOUSTON THAT WILL FOCUS ON ENGINEERING EDUCATION OUTREACH. OUR DOE/NNSA PARTNERS INCLUDE CONSOLIDATED NUCLEAR SECURITY (CNS) PANTEX, LOS ALAMOS NATIONAL LABORATORY (LANL), AND SANDIA NATIONAL LABORATORY (SNL)., G8876996369, G8943657973
OpenAlex ID: W7129241358