Abstract
Residual stress originated from thermal expansion mismatch determines the mechanical properties of ceramic matrix composites (CMCs). Here, continuous SiC fiber reinforced SiC matrix (SiCf/SiC) composites were fabricated by nano-infiltration and transient eutectic-phase (NITE) method, and the residual stress of the composites was investigated using high-temperature Raman spectrometer. With temperature increasing from room temperature to 1400 °C, the residual stresses of the matrix and the fiber decrease from 1.29 to 0.62 GPa and from 0.84 to 0.55 GPa in compression respectively, while that of the interphase decreases from 0.16 to 0.10 GPa in tension. The variation of residual stress shows little effect on the tensile strength of the composites, while causes a slight decrease in the tensile strain. The suppression of fiber/matrix debonding and fiber pulling-out caused by the residual stress reduction in the interphase is responsible for the decreasing tensile strain. This work can open up new alternatives for residual stress analysis in CMCs.
Highlights
IntroductionJ Adv Ceram 2020, 9(5): 567–575 stress is inevitably formed due to the thermal expansion mismatch of the constituent phases
Ceramic matrix composites (CMCs), possessing excellent mechanical properties and corrosion resistance at highJ Adv Ceram 2020, 9(5): 567–575 stress is inevitably formed due to the thermal expansion mismatch of the constituent phases
The SiCf/SiC composites were prepared by a nano-infiltration and transient eutectic-phase (NITE) process, which is specified in previous literature [20]
Summary
J Adv Ceram 2020, 9(5): 567–575 stress is inevitably formed due to the thermal expansion mismatch of the constituent phases. There are several methods to measure residual stress, including X-ray diffraction [3,4], neutron diffraction [5,6], Raman spectroscopy [7,8], and mechanical loading [9,10] Both X-ray and neutron diffraction methods obtain residual stress by measuring average thermal strain. Wing et al [12] adopted Raman spectroscopy to investigate the residual stress in reaction-bonded SiC, and measured residual compressive stress as high as ~2.0 GPa in the silicon phase and residual tensile stress as high as ~2.3 GPa in the SiC phase, both of which are higher than those calculated from thermal expansion mismatch. Raman spectroscopy has been widely used to measure residual stress in ZrB2–SiC [14], B4C–ZrB2 [15], Cf/SiC [16] composites, indicating its great universality in residual stress analysis
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
