High Temperature Solid Particle Erosion in a Melt-Infiltrated SiC/SiC Ceramic Matrix Composite

2021 ◽  
Author(s):  
Michael J. Presby
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Gas Turbines ◽  
Material Removal ◽  
Gas Flow ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Solid Particles ◽  
Material System

Abstract Ceramic matrix composites (CMCs) are an enabling propulsion material system that offer weight benefits over current Ni-based superalloys, and have higher temperature capabilities that can reduce cooling requirements. Incorporating CMCs into the hot section of gas-turbine engines therefore leads to an increase in engine efficiency. While significant advancements have been made, challenges still remain for current and next-generation gas-turbines; particularly when operating in dust-laden or erosive environments. Solid particles entrained in the gas flow can impact engine hardware resulting in localized damage and material removal due to repeated, cumulative impacts. In this study, the erosion behavior of a melt-infiltrated (MI) silicon carbide fiber-reinforced silicon carbide (SiC/SiC) CMC is investigated at high temperature (1,200 °C) in a simulated combustion environment using 150 μm alumina particles as erodent. Particle impact velocities ranged from 100 to 200 m/s and the angle of impingement varied from 30° to 90°. Erosion testing was also performed on α-SiC to elucidate similarities and differences in the erosion response of the composite compared to that of a monolithic ceramic. Scanning electron microscopy (SEM) was used to study the post-erosion damage morphology and the governing mechanisms of material removal.

High Temperature Solid Particle Erosion in a Melt-Infiltrated SiC/SiC Ceramic Matrix Composite

2021 ◽  
Author(s):  
Michael Presby
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Gas Turbines ◽  
Material Removal ◽  
Gas Flow ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Solid Particles ◽  
Material System

Abstract Ceramic matrix composites (CMCs) are an enabling propulsion material system that offer weight benefits over current Ni-based superalloys, and have higher temperature capabilities that can reduce cooling requirements. Incorporating CMCs into the hot section of gas-turbine engines therefore leads to an increase in engine efficiency. While significant advancements have been made, challenges still remain for current and next-generation gas-turbines; particularly when operating in dust-laden or erosive environments. Solid particles entrained in the gas flow can impact engine hardware resulting in localized damage and material removal due to repeated, cumulative impacts. In this study, the erosion behavior of a melt-infiltrated (MI) silicon carbide fiber-reinforced silicon carbide (SiC/SiC) CMC is investigated at high temperature (1,200 °C) in a simulated combustion environment using 150 µm alumina particles as erodent. Particle impact velocities ranged from 100 to 200 m/s and the angle of impingement varied from 30° to 90°. Erosion testing was also performed on a-SiC to elucidate similarities and differences in the erosion response of the composite compared to that of a monolithic ceramic. Scanning electron microscopy (SEM) was used to study the post-erosion damage morphology and the governing mechanisms of material removal.

Thermal Diffusivity Imaging of Ceramic Composites

1993 ◽  
Author(s):  
K. Elliott Cramer ◽  
William P. Winfree ◽  
Edward R. Generazio ◽  
Ramakrishna Bhatt ◽  
Dennis S. Fox ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Diffusivity ◽  
Silicon Nitride ◽  
Matrix Material ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Ceramic Composites ◽  
Fiber Direction ◽  
Large Area

Strong, tough, high temperature ceramic matrix composites are currently being developed for application in advanced heat engines. One of the most promising of these new materials is a SiC fiber-reinforced silicon nitride ceramic matrix composite (SiCf/Si3N4). The interfacial shear strength in such composites is dependant on the integrity of the fiber’s carbon coating at the fiber-matrix interface. The integrity of the carbon rich interface can be significantly reduced if the carbon is oxidized. Since the thermal diffusivity of the fiber is greater than that of the matrix material, the removal of carbon increases the contact resistance at the interface reducing the thermal diffusivity of the composite. Therefore thermal diffusivity images can be used to characterize the progression of carbon depletion and degradation of the composite. A new thermal imaging technique has been developed to provide rapid large area measurements of the thermal diffusivity perpendicular to the fiber direction in these composites. Results of diffusivity measurements will be presented for a series of SiCf/Si3N4 (reaction bonded silicon nitride) composite samples heat-treated under various conditions. Additionally, the ability of this technique to characterize damage in both ceramic and other high temperature composites will be shown.

High-Temperature Interlaminar Tension Test Method Development for Ceramic Matrix Composites

2013 ◽  
Author(s):  
Todd Engel
Keyword(s):  
High Temperature ◽  
Method Development ◽  
Standardized Test ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Test Method ◽  
Test Technique ◽  
Structural Applications

Ceramic Matrix Composite (CMC) materials are an attractive design option for various high-temperature structural applications. In particular, the use of CMC materials as a replacement for state-of-the-art nickel-based superalloys in hot gas path turbomachinery components offers the potential for significant increases in turbine system efficiencies, due largely to reductions in cooling requirements afforded by the increased temperature capabilities inherent to the ceramic material. However, two-dimensional fabric-laminated CMCs typically exhibit low tensile strengths in the thru-thickness (interlaminar) direction, and interply delamination is a concern for some targeted applications. Currently, standardized test methods only address the characterization of interlaminar tensile strengths at ambient temperatures; this is problematic given that nearly all CMCs are slated for service in high-temperature operating environments. This work addresses the development of a new test technique for the high-temperature measurement of interlaminar tensile properties in CMCs, allowing for the characterization of material properties under conditions more analogous to anticipated service environments in order to yield more robust component designs.

Failure Evaluation of a SiC/SiC Ceramic Matrix Composite During In-Situ Loading Using Micro X-ray Computed Tomography

2019 ◽  
Vol 25 (3) ◽  
pp. 583-591 ◽  
Author(s):  
John Thornton ◽  
Benedicta D. Arhatari ◽  
Mitchell Sesso ◽  
Chris Wood ◽  
Matthew Zonneveldt ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Silicon Carbide ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Nitride Phase ◽  
X Ray ◽  
Pull Out ◽  
Computed Tomography Images ◽  
X Ray Computed

AbstractIn this study, we have examined ceramic matrix composites with silicon carbide fibers in a melt-infiltrated silicon carbide matrix (SiC/SiC). We subjected samples to tensile loads while collecting micro X-ray computed tomography images. The results showed the expected crack slowing mechanisms and lower resistance to crack propagation where the fibers ran parallel and perpendicular to the applied load respectively. Cracking was shown to initiate not only from the surface but also from silicon inclusions. Post heat-treated samples showed longer fiber pull-out than the pristine samples, which was incompatible with previously proposed mechanisms. Evidence for oxidation was identified and new mechanisms based on oxidation or an oxidation assisted boron nitride phase transformation was therefore proposed to explain the long pull-out. The role of oxidation emphasizes the necessity of applying oxidation resistant coatings on SiC/SiC.

Experimental Heat Transfer and Boundary Layer Measurements on a Ceramic Matrix Composite Surface

2020 ◽  
Author(s):  
Peter H. Wilkins ◽  
Stephen P. Lynch ◽  
Karen A. Thole ◽  
San Quach ◽  
Tyler Vincent
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Surface Morphology ◽  
Gas Turbines ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Composite Surface ◽  
Weave Pattern ◽  
The Impact

Abstract Ceramic matrix composites (CMCs) are quickly becoming more prevalent in the design of gas turbines due to their advantageous weight and thermal properties. While there are many advantages, the CMC surface morphology differs from that of conventional cast airfoil components. Despite a great deal of research focused on the material properties of CMCs, little public work has been done to investigate the impact that the CMC surface morphology has on the boundary layer development and resulting heat transfer. In this study, a scaled-up CMC weave pattern was developed and tested in a low speed wind tunnel to evaluate both heat transfer and boundary layer characteristics. Results from these experiments indicate that the CMC weave pattern results in augmented heat transfer and flow field properties that significantly vary locally when compared to a smooth surface.

The Laser-Assisted Edge Milling of Ceramic Matrix Composites

2009 ◽  
Author(s):  
Jay C. Rozzi ◽  
Michael D. Barton
Keyword(s):  
Material Removal ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Production Costs ◽  
Matrix Composites ◽  
Machining Processes ◽  
Cycle Times ◽  
Conventional Machine ◽  
Conventional Machining

On this Phase I SBIR project, Creare’s overall objective was to develop and transition a technology that will increase cutting tool life and reduce overall production costs of machining ceramic matrix composite (CMC) materials. We successfully demonstrated the feasibility of machining CMC materials using the Laser-Assisted Machining (LAM) approach, which utilizes a laser to preheat a thin layer of the CMC material prior to its removal using conventional machine tools. In particular, we demonstrated that the cutting forces were reduced by as much as 40% compared to conventional machining processes. This reduction enables increased processing speeds which decrease cycle times and overall processing costs. Additionally, we developed and validated a comprehensive thermal model for the edge machining of CMCs. When combined with the experimental results, the temperatures near the material removal interface for the optimal LAM condition were predicted.

A Three-Phase Shear-Lag Model for Longitudinal Cracking of a Ceramic Matrix Composite Ply With Thick Fiber Coatings

2015 ◽  
Vol 83 (1) ◽  
Author(s):  
Lucas R. Hansen ◽  
Anthony M. Waas
Keyword(s):  
Ceramic Matrix Composite ◽  
Stress Transfer ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Cracking ◽  
Material System ◽  
Shear Lag ◽  
Thick Fiber ◽  
The Matrix ◽  
Lag Model

During progressive cracking of cross-ply ceramic matrix composites (CMCs), load is transferred from the fiber to the matrix in the longitudinal (0 deg) ply via shear through a compliant interphase layer, also referred to as the coating. In the material system of interest, this coating has significant thickness relative to the fiber diameter. The damage process in the cross-ply CMC is observed to be as follows: (1) elastic deformation, (2) cracking of the transverse plies, (3) matrix cracking within the longitudinal plies, (4) failure of longitudinal fibers, and (5) pullout of the cracked fibers from the matrix. In this paper, the focus is on the longitudinal (0 deg) ply. Existing shear-lag models do not fully represent either the stress transfer through the coating or the true accumulations of shear and normal stresses in the matrix. In the current study, a model is developed that takes into account both of these factors to provide a more accurate, analytical representation of the stress distribution and progressive damage accumulation in a longitudinal CMC ply.

scholarly journals Cyclic oxidation behaviour of ZrB2 -20 vol.%MoSi2 based ultra-high temperature ceramic matrix composite between 1100°C and 1300°C

2021 ◽  
Author(s):  
Mainak Saha
Keyword(s):  
High Temperature ◽  
Cyclic Oxidation ◽  
Ceramic Matrix Composite ◽  
Oxidation Kinetic ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Oxidation Behaviour ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Ultra High Temperature

While descending through different layers of atmosphere with tremendously high velocities, hypersonic re-entry nosecones fabricated using ultra-high temperature ceramic matrix composites (UHTCMCs) are subjected to repeated thermal shocks. This necessitates extensive investigations on the cyclic oxidation behaviour of UHTCMCs at temperatures ranging from 1100°C to 1300°C (service temperature of the nosecones). To this end, the present work is aimed at investigating the cyclic oxidation behaviour of ZrB2 -20 vol.%MoSi2 (ZM20) UHTCMC (a very widely investigated ZM CMC) by carrying out cycles for 6h, at 1cycle/h and estimating oxidation kinetic law. This has been followed by extensive characterisation using X-Ray Diffraction (XRD) to indicate the phases formed during oxidation and Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), in order to determine the chemical composition of the oxides formed between 1100°C and 1300°C.

Ceramic Matrix Composites Application in Automotive Gas Turbines

1997 ◽  
Vol 119 (4) ◽  
pp. 790-798 ◽  
Author(s):  
Takao Izumi ◽  
Hiroshi Kaya
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Gas Turbines ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Screening Tests ◽  
Particle Impact ◽  
Matrix Composites ◽  
Test Pieces ◽  
Monolithic Ceramics

We are conducting the development of ceramic matrix composites (CMC) and components made of CMC for a 100 kW automotive ceramic gas turbine (CGT) as shown in Fig. 1. When compared to monolithic ceramics (MC), CMC that we have developed demonstrate superior strength characteristics in terms of resistance to particle impact and thermal shock. We have conducted evaluation tests on the strength of CMC components in which MC such as silicon nitride and silicon carbide were used as a reference for comparison with CMC in the same testing process as employed for components made of MC such as silicon nitride and silicon carbide. It was confirmed that actual components made of CMC realized approximately the same strength as the test pieces. Furthermore, some CMC components have already passed screening tests that evaluated the strength of the components. It was therefore confirmed that the potential exists for the possibility of testing these components in high-temperature assembly tests and engine tests.

Ceramic Matrix Composites Application in Automotive Gas Turbines

1996 ◽  
Author(s):  
Hiroshi Kaya ◽  
Takao Izumi
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Gas Turbines ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Screening Tests ◽  
Particle Impact ◽  
Matrix Composites ◽  
Test Pieces ◽  
Monolithic Ceramics

We are conducting the development of ceramic matrix composites (CMC) and components made of CMC for a 100 kW automotive ceramic gas turbine (CGT) as shown in Fig.1. When compared to monolithic ceramics (MC), CMC that we have developed demonstrate superior strength characteristics in terms of resistance to particle impact and thermal shock. We have conducted evaluation tests on the strength of CMC components in which MC such as silicon nitride and silicon carbide were used as a reference for comparison with CMC in the same testing process as employed for components made of MC such as silicon nitride and silicon carbide. It was confirmed that actual components made of CMC realized approximately the same strength as the test pieces. Furthermore, some CMC components have already passed screening tests that evaluated the strength of the components. It was therefore confirmed that the potential exists for the possibility of testing these components in high temperature assembly tests and engine tests.

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