| 摘要 |
Carbon fiber brake preforms (20), specifically, annular discs built up of fabric arc segments (21) composed of continuous fibers (25) and staple fibers (26). Most of the continuous fibers (25) in the fabric segments (21) are arranged to be located within 60° of radially from the inner diameter to the outer diameter of the annular disc (20). The fabric arc segments have substantially all of their continuous fibers oriented in the radial direction and parallel to the segment arc bisector, or the segments are arranged in alternating layers in which, respectively, half the continuous fibers are oriented at a +45 degree angle with respect to the segment arc bisector and half the continuous fibers are oriented at a -45 degree angle with respect thereto. Methods for making preform composites comprise providing needle-punched nonwoven fabric of unidirectional continuous fibers and staple fibers, making a plurality of fabric segments, arranging the segments in a multilayered intermediate, heating the multilayered intermediate to convert the fibers to carbon, and densifying the carbonized product. In brake discs made as described, fiber pull-out is minimized, reducing mechanical wear. The disclosed preform fiber architecture reduces wear rates while maintaining brake disc strength. |
