High Strength Structural Carbon Solids from Pitch Powders

This proposal describes a novel, inherently simple processing concept for the synthesis of monodispersed pitch powders suitable for use in the fabrication of high strength monolithic carbon and carbon-carbon composite artifacts. The starting materials may be either devolatilized isotropic petroleum pitch or pitches consisting entirely of polyaromatic mesophase. Powder preparation mimics the approach used in creating homogeneous powders for high strength ceramics, namely, the generation of uniform spheres in solution, followed by separation and drying. By producing ceramic artifacts with dramatic absolute property improvements, and much less scatter in properties, powders derived from solution chemistry have revolutionized ceramic processing. Remarkable recent advances in the sintering of pitch powders demonstrate that carbon artifacts with flexural strengths exceeding 200 MPa (29 ksi) may be achieved using conventionally comminuted powders. The proposed work aims to demonstrate that sintered homogeneous pitch powders offer even greater improvements over crushed precursor in the fabrication of carbon solids. Sample carbon plates will be processed from the homogeneous powders and compared with industry standard UCAR ATJ and POCO AXF-5Q. The thickness of coupon specimens will approximate that of near net shape carbon pistons, the primary intended application.