Strength Analysis of a Micro-Rocket Combustion Chamber

Noonan, Erin E.; Protz, Christopher S.; Peles, Yoav; Mark, S

doi:10.1557/proc-687-b4.6

Cited by 2 publications

(7 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[23] In practice, measured silicon strengths tend to stay well below 10 GPa and tend to be in the range of a few GPa. [8,31,17] Similar single crystal materials such as germanium have achieved tensile strengths close to their theoretical strength in practice. [30] The achievement of germanium suggests that it may be possible for silicon to achieve more than ten gigapascals or a strength value close to its theoretical strength.…”

Section: Silicon Propertiesmentioning

confidence: 87%

“…• Wet etch of hydrofluoric acid/nitric acid/DI water (HF/HNO 3 ) [8] • Wet etch of potassium hydroxide (KOH) [8] • Dry etch of SF 6 [8,31] • Oxidize and remove oxide [37] • Surface Migration/Hydrogen annealing [25] According to Chen's work, the HF/HNO 3 wet etch showed a 93% improvement in…”

Section: Methods To Reduce Surface Roughnessmentioning

confidence: 99%

“…Mechanical silicon structures include pressure transducers consisting of thin silicon membranes, microscale beams, and MEMS valves [18], [39,21,10], [7,19]. More advanced structures include gears, turbine engines with rotating blades, and chemical rocket engines [12], [8], [31].…”

Section: Structural Silicon Memsmentioning

confidence: 99%

“…In addition, the substrate also becomes rough after this process. Sacrificial thermal oxidation has been utilized to improve sidewall quality [30], [31] ; however, the process consumes too much silicon and builds up residual stress. By employing hydrogen annealing, we demonstrate that sidewall scalloping can be dramatically reduced.…”

Section: Sidewall Roughness Reductionmentioning

confidence: 99%

“…This is done using a model for the RHFS given by Noonan. [31] Noonan modeled the RHFS by superimposing two loading conditions. The first loading condition is a plate with a circular hole in the middle subject to a bending moment.…”

Section: Determining Weibull Parameters For the Rhfsmentioning

confidence: 99%

See 4 more Smart Citations

Single Crystal Silicon as a Macro-World Structural Material: Design of Compact, Lightweight High Pressure Vessels

Garza¹

2008

44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference &Amp;amp; Exhibit

View full text Add to dashboard Cite

Single crystal silicon has promising inherent structural properties which are attractive for weight sensitive applications. Single crystal silicon, however, is a brittle material which makes the usable strength that can be obtained from silicon devices dependent on flaws or cracks that can arise during fabrication in a sample that begins relatively free of defects. This research explores the use of micro-machined, single crystal silicon (Si) for high-strength macro-scale application and determines its practical advantages when compared to conventional approaches. The major contributions of this thesis includes evaluation of wafer-scale silicon for macro-world applications, identification of cellular pressure vessels as a promising wafer-scale silicon device, identification of design criteria for brittle pressure vessels and quantified metrics for a competitive silicon pressure vessel design, identification of DRIE failure mechanisms, elucidation of the role of wafer-level strength variation related to surface morphology variation in wafer-scale structures, and identification of promising strength recovery techniques and promising avenues to explore for further strength improvements. High pressure vessels for aerospace applications with volumes of 10's of cc's were designed under the premise that the superior strength-to-density ratio of Si and postprocessing strength recovering techniques can compensate for fabrication technology limitations that constrain the vessel shape and for the brittle nature of the material. A combination of literature review, analysis, and numerical simulations suggest that there are single crystal silicon fabrication technology compromised pressure vessel designs that can have lower structural mass to pressurant mass ratios than conventional pressure vessel designs at design pressures above about 6000 psi. A honeycomb geometry offered the best results of those studied. The honeycomb silicon pressure vessel offers the possibility of integrated micro-valves, regulators and sensors. Such vessels would be useful for nano and pico satellites and for launch vehicles. Fabrication processes and strength recovering techniques were explored experimentally to understand and improve the usable strength of microfabricated single crystal silicon macro-structures. It was found that silicon strength will vary across a DRIE etched wafer as a result of submicron sidewall roughness variation independent 157

show abstract

Section: Silicon Propertiesmentioning

confidence: 87%

Section: Methods To Reduce Surface Roughnessmentioning

confidence: 99%