Johnny Lincoln, Wylie Simpson, Antonios Tontisakis

Axiom Materials, Santa Ana, CA

ABSTRACT

With major development programs underway and a growing interest in more complex oxide-oxide ceramic matrix composite (CMC) fabric weaves and resin systems, an investment in production-scale manufacturing is required to satisfy the demand. CMC prepreg has traditionally been manufactured through a “hand-prepregging” process making scale-up difficult. Due to limitations in the resin system and the process itself the result is CMC prepreg with poor uniformity and infiltration into the fiber. Complex fabric weaves, such as lower cost high denier fabrics, require a resin system and coating process that can infiltrate the fabric’s thick fiber bundles. Axiom Materials, Inc has invested in production-scale coating equipment that allows continuous ceramic fabric impregnation. Batch to batch variation is eliminated through controlled alignment features and tensioning devices and infiltration of the fiber bundle is uniform and consistent. CMC prepreg manufactured with production scale coating equipment allows for resin system and fabric variability resulting in a more traditional and commercial product with a wide range of uses. Axiom Materials, Inc evaluates the properties of high denier oxide-oxide ceramic prepreg manufactured with production-scale coating equipment

Figure 1: CMC Production Flowchart.

OX-OX CMC PROPERTIES

Ox-Ox CMC vs Metals (Ti & Ni)

» High Temperature (Operating temperatures up to 1200°C)

» Higher Strength

» Lower Density (2.5 vs ~ 4.5g/cc)

» Low dielectric

» Orientable properties

» Corrosion resistance

» Low creep / high modulus

Ox-Ox CMC vs Monolithic

» Higher Strength

» Lower Density (2.5 vs 3.0-3.7g/cc)

» Orientable properties

» Damage tolerance / durability / stiffness

Figure 2: Material property charts comparing CMCs to other materials.

OX-OX CMC APPLICATIONS

Aerospace / Hypersonics / Missiles: turbine engine components, reentry surfaces, nozzles, exhaust ducts/tubes, heat shields, propulsion, high-temperature radomes, high-temperature sensing equipment
Energy / Industrial: refractory hardware, incineration, heat shielding, gas turbines and microturbines, oxide fuel cells, tubing
Automotive / Motorsports: exhaust ducts, mufflers, high wear components, brake ducting

Figure 3: Examples of CMC applications.

CMC MATERIALS CAPABILITY

Figure 4: CMC Materials Chart.

SB: Solvent-Based

WB: Water-Based

AX-810 solvent-based Alumina-Silica slurry selected as fabric coating resin for evaluation

NEXTEL^TM CERAMIC FABRIC

Table 1: 3M^TM Nextel^TM Ceramic Fiber Properties

Table 2: 3M Nextel^TM Ceramic Fabric Properties

Figure 5: Nextel^TM 610 Fabric Architectures. (Left) 8HS1500D; (Middle Left) 5HS3000D; (Middle Right) 2x2TW4500D; (Right) Spread Tow PW100000D

High-Denier Woven Fabrics

Build on Industry Standard

» Large tow bundles at lower pic count to mimic Nextel 1500 Denier Tow, 8 Harness Satin Weave

» Direct substitution for components already in production

Weaves that Increase Drapability

» Ability to form more complex structures

Larger Tow Bundles

» Greater per-ply thickness leads to less material required to target thickness

– Reduced Yardage
– Lower Fabrication Labor
– Reduced Waste

Lower Cost

AUTOMATED COATING PROCESS