Surface Damage in Micro-Architected Materials for High Heat Flux Applications
- Author(s): Rivera, David
- Advisor(s): Ghoniem, Nasr M
- et al.
A study of the response of microarchitected surfaces under thermo-mechanical loading is presented. The design philosophy motivating the creation and investigation of such uniquely featured coatings is reviewed. The development of a testing facility fashioned to impose extreme heat loads on microarchitected and planar specimens is outlined. Experimental results contrasting the behavior of microarchitected and planar surfaces undergoing high heat flux testing are found to favor surface architectures by mitigating plastic strain. For the case of planar surfaces it was found that recrystallization under high heat flux loading leads to increased susceptibility to cracking. A dislocation based visco-plasticity model corroborates the experimental determination of reduced plastic distortion relative to planar materials. The combination of experimental results and theoretical modeling reveal that microarchitected surfaces and features can be designed to alleviate thermo-mechanical damage. Modeling efforts suggest that microarchitected features provide for reductions in dislocation density and internal stress generation relative to planar surfaces. The curtailing of such internal parameters in the micron-scale entities comprising a microarchitected surface results in a tunable stress response not possible in planar materials. Potential future design optimization routes are discussed.