Stacking fabric saves time during atomic layer deposition

Ceramics are stiff and resistant to wear, oxidation, and high temperatures. Reinforcing ceramics with embedded fibers, which have a high tensile strength, overcomes ceramics’ limitations.

These materials, known as ceramic matrix composites, have high-temperature applications. However, the fibers must be coated, often with multiple layers, to protect them from oxidation and to optimize their mechanical decoupling with the matrix.

Atomic layer deposition (ALD) can be used to apply thin, uniform coatings onto fibers before embedding them into a ceramic matrix. Previously, researchers have used ALD to coat single fibers, fiber bundles, or woven fabrics of fibers. Dill et al. used ALD to successfully coat stacks of fabrics in a single batch.

The authors coated carbon and silicon carbide reinforcing fibers with layers of alumina, titania-furfuryl alcohol hybrid, and titanium phosphate. Scanning electron microscopy showed the coatings were uniform. Applying the coating to stacked fabrics increased the total area of coated fabric per batch to 560 square centimeters.

They found the inorganic layers of coating protect the fibers oxidation. They believe the hybrid material, titania-furfuryl alcohol hybrid, may mechanically decouple the fiber and matrix.

“The coated fabrics may be used in advanced fiber reinforced ceramic matrix composites,” said author Pauline Dill. “The coating may improve the oxidation resistance of these composites as well as reduce their tendency to fracture.”

Next, the authors will embed these coated fibers in a ceramic matrix to test their mechanical properties and use their results to further optimize coating properties.

Source: “Atomic layer deposition onto fabrics of carbon and silicon carbide fibers: Preparation of multilayers comprising alumina, titania-furfuryl alcohol hybrid and titanium phosphate,” by Pauline Dill, Florian Pachel, Christian Militzer, Alexander Held, Georg Puchas, Stefan Knohl, Walter Krenkel, Christoph Tegenkamp, and Werner Andreas Goedel, JVST: A (2021). The article can be accessed at https://aip.scitation.org/doi/full/10.1116/6.0001193 .

This paper is part of the Atomic Layer Deposition (ALD) Collection, learn more here .