LOX Compatible Toughened Bismaleimide Matrix Thermally Conductive Fiber Composites Part Ⅱ: ASTM D2512 Specimen Fabrication, Cleaning and Testing

摘要

Composites of 61.5 to 63.7 % V_f were fabricated out of baseline T650-35-UC309 and the thermally conductive YSH50A and YSH60A fibers using the toughened Bismaleimide 5250-4 RTM matrix resin. ASTM D2512-95 (2002)el (D2512) specimens were fabricated from these composites and the toughened Bismaleimide neat resin. D2512 mechanical impact tests conducted at 72 ft·lbs (98 J) on six sets of specimens indicated that both thermally conductive fibers repeatedly improved the D2512 liquid oxygen (LOX) compatibility of their composites by 1700+ % over the baseline fiber composite's. This improvement occurred regardless of the thickness of the tested thermally conductive fibered composite specimens or type of thermally conductive fiber used. Only flash type reactions were detected for the thermally conductive specimens, whereas, flash, char and noise type reactions were detected for the baseline fiber composite specimens. The 100 % D2512 ignition rate exhibited by the neat resin specimens implies that the D2512 LOX compatibility improvement exhibited by the thermally conductive fiber composite's over the baseline fiber composites is directly attributable to the use of these thermally conductive fibers.