Book Description

Efforts to improve the impact resistance of B/Al are reviewed and analyzed. Nonstandard thin-sheet Charpy and Izod impact tests and standard full-size Charpy impact tests were conducted on composites containing unidirectional 0.10-,0.14-, and 0.20-mm-(4-, 5.6-, and 8-mil- ) diameter boron fibers in 1100, 2024, 5052, and 6061 Al matrices. Impact failure modes of B/Al are proposed in an attempt to describe the mechanisms involved and to provide insight for maximizing impact resistance. The impact strength of B/Al was significantly increased by proper selection of materials and processing. The use of a ductile matrix (1100 Al) and large-diameter (8-mil) boron fibers gave the highest impact strengths. This combination resulted in improved energy absorption through matrix shear deformation and multiple fiber breakage.