Density advanced structural ceramics

A reinforcing fiber with high strength and modulus with 2.7 density. Primary purpose for this development was for the reinforcement of metal matrix and ceramic matrix composite structures used in advanced aerospace applications by the military. SiC fibers were developed to replace boron fibers in these RPs, where boron had its drawbacks principally degradation of mechanical properties at temperatures greater than 540C (lOOOF) and very high cost. 

The various challenges of the improvement in the ORR activity and the durability have been advancing by means of alloying, formation of Pt skin layers, and core-shell preparation methods. Approaches based on non-precious metals are proceeding as well. In addition, the further optimization of the thin CL structure by use of new, durable support materials (e.g., graphitized carbon blacks and conductive ceramic supports) should help to improve the effectiveness of Pt and the durability, as well as specific gas transport problems in the CL under high current density operating conditions. 

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