Abstract

The mechanical behavior of silicon oxycarbide polymer derived ceramics (SiOC-PDC) without and with a graphene toughening phase was studied under uniaxial compressive load with zero dwell time and with 200 second dwell time step loading in combination with in-situ Raman spectroscopy to determine spectral vibrational response of SiOC under compressive stress. SiOC without and with graphene ceramic samples were produced through the replica templating technique. The compressive strengths of SiOC without and with a graphene toughening phase measured with zero dwell time was determined to be equal to 165.65 (SD 54.21) and 163 (SD 24.2) MPa, respectively, while compressive strengths of the selected ceramics measured with 200 second dwell time step loading was determined to be equal to 228.97 and 186.42 MPa, respectively. Weibull analysis of 27 pure SiOC ceramic samples and 31 SiOC-graphene ceramic composite samples tested with zero dwell time was performed to calculate their probability of failure. Weibull parameters, such as Weibull modulus and characteristic strength, were determined to be equal to m = 3.46 and 190.41 MPa for pure SiOC ceramics and m = 7.71 and 178.73 MPa for SiOC with graphene ceramic composite. In-situ Raman spectroscopy was performed during compression of SiOC without and with a graphene toughening phase dwelled for 200 seconds during step loading, which allowed the collection of Raman spectra of graphitic carbon nanodomains in SiOC at different applied compressive stresses. The properties of the D and G bands of the graphitic nanodomains in SiOC, such as peak intensity, peak area, peak position and FWHM, were analyzed as a function of applied compressive stress. Piezospectroscopic coefficients were then calculated to be equal to 10.994 and -10.269 cm-1/GPa for the G band and 31.538 and 6.341 cm-1/GPa for the D band of pure SiOC and SiOC with a graphene toughening phase, respectively.

Notes

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Graduation Date

2021

Semester

Spring

Advisor

Orlovskaya, Nina

Degree

Master of Science in Mechanical Engineering (M.S.M.E.)

College

College of Engineering and Computer Science

Department

Mechanical and Aerospace Engineering

Degree Program

Mechanical Engineering; Mechanical Systems Track

Format

application/pdf

Identifier

CFE0008548; DP0024224

URL

https://purls.library.ucf.edu/go/DP0024224

Language

English

Release Date

May 2021

Length of Campus-only Access

None

Access Status

Masters Thesis (Open Access)

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