Microstructural Evaluation of Aligned, Short Fiber TUFF Material

Abstract

The Tailorable Universal Feedstock for Forming (TuFF) material is comprised of highly aligned discontinuous fibers that achieves a high level of mechanical properties with large in-plane extensibility for forming of complex geometries. The paper characterizes the TuFF microstructure in terms of areal weight and fiber volume fraction and statistical distributions of fiber length, fiber-fiber spacing and fiber alignment using microscopy and X-ray Computed-Tomography with custom developed algorithms for data reduction. The TuFF program has demonstrated full property translation of stiffness and strength compared to continuous prepreg (60% fiber volume fraction) when 95% of all fibers are aligned within 5° and have a minimum fiber aspect ratio (length over diameter) of 600.