Experimental Permeability and Porosity Determination of All-Oxide Ceramic Matrix Composite Material

Area of Science:

• Materials Science
• Ceramic Engineering
• Composite Materials

Background:

• All-oxide ceramic matrix composites (CMCs) are advanced materials with potential applications in harsh environments.
• Understanding their transport properties, such as water permeability, is crucial for predicting performance and durability.

Purpose of the Study:

• To experimentally investigate and characterize the water permeability of an all-oxide CMC.
• To analyze the influence of various structural parameters on the water permeability of the composite material.

Main Methods:

• Construction and commissioning of a dedicated test rig for water permeability measurements.
• Testing of five different CMC tube configurations varying in fiber roving strength, winding angle, fiber arrangement, and matrix grain size.
• Microstructure and porosity analysis using scanning electron microscopy (SEM).

Main Results:

• New data on water permeability for CMCs with varying structural parameters were obtained.
• Observed a decrease in water permeability over time, similar to other porous materials, as liquid is pressed through the composite.
• SEM analysis provided insights into the relationship between microstructure, porosity, and permeability.

Conclusions:

• The water permeability of all-oxide CMCs is significantly affected by structural parameters.
• The time-dependent decrease in permeability suggests a self-sealing or clogging mechanism within the composite structure.
• These findings are relevant for the application of CMCs as liners in oxy-combustion chambers.