PROCESSING OF CONTINUOUS-CERAMIC-FIBER-REINFORCED INTERMETALLIC COMPOSITES BY PRESSURE CASTING

[摘要] Pressure casting because of its flexibility and greater promise for economy compared with other composite-processing routes is being extensively used to fabricate low temperature composites. A pressure-casting apparatus has been developed which allowed, for the first time, the fabrication of fiber-reinforced high temperature composite materials. A series of Ni3Al, Ti-Al and Fe3Al composites, unidirectionally reinforced with either DuPont's fiber FP (Al2O3) or PRD-166 (Al2O3-20wt.%ZrO2) continuous fibers which were 20-mu-m in diameter, have been produced. Optical and transmission electron microscopy have been employed to characterize the microstructure. In the case of nickel and iron aluminides it was found necessary to add a small amount (0.5-1 at.%) of a strong oxide former such as titanium, yttrium or zirconium to improve wetting and therefore to achieve complete infiltration. This paper will focus on the fiber-matrix bonding, and the nature and the extent of fiber-matrix reaction in these composites. Mechanical testing indicated that reinforcing Ni3Al with PRD-166 fibers resulted in a twofold increase in specific modulus and a fivefold increase in strength.

[发布日期] 1991-10-01

[效力级别]  Proceedings Paper