Nanoscale Energy Coupling and Material Behaviors in Selective Laser Sintering of Ultra-High Temperature Ceramics
Abstract
The goal of the proposed research is to establish the basic science to understand the laser-material interaction mechanisms underlying the electronic dynamics, nanoscale energy coupling, microstructural evolution, and process-microstructure-property relationship during selective laser sintering (SLS) of ultra-high temperature ceramics (UHTCs). Conventional manufacturing processes for sintering of UHTC powders require high temperatures, a long time, applied pressure, or sintering additives, due to their strong covalent bonds and low self-diffusion coefficients. To fill this gap, a novel SLS additive manufacturing (AM) process of UHTCs has been developed by our team, which features a high temperature, ultrafast time, and ultrahigh heating-cooling rates. Compared to the traditional manufacturing processes, the fundamental mechanisms of SLS of UHTCs are poorly understood. This research proposal is driven by the central hypothesis that SLS of UHTCs has the following unique features during the interactions of laser beams with UHTCs- (a) dynamic electronic response to laser irradiation, (b) nanoscale energy coupling due to near-field effects, and (c) localized melting and grain-boundary diffusion. To fulfill the research goal and test the hypothesis, this project will pursue three research objectives to- 1) monitor the electronic dynamics by transient infrared reflectance spectroscopy and simulate nanoscale energy coupling by COMSOL; 2) reveal the microstructural evolution and sintering mechanisms by in situ and ex situ electron microscopy; and 3) develop the UHTC powder feedstock for AM and investigate the process-microstructure-property relationship of SLSed UHTCs. The anticipated impact is to establish a fundamental understanding of laser-material interaction mechanisms associated with dynamic photonic, electronic, thermal, and mechanical properties of UHTCs during the SLS processes, which can be translated to a broad range of ceramic materials. A better understanding of the fundamental mechanisms will guide further development of the SLS technology for AM of UHTC components for hypersonic vehicles.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 06, 2024
- Source ID
- FA95502310490
Entities
People
- Bai Cui
Organizations
- Air Force Office of Scientific Research
- Office of the Secretary of Defense
- University of Nebraska–Lincoln