| Vitreous calcia/alumina (CA) fibers of eutectic composition (46.5 wt % calcia/53.5 wt % alumina) were produced by the inviscid melt spinning (IMS) process. Thermal decomposition experiments of hydrocarbons proved the efficiency of propane as an excellent carbon-forming reactant gas. This IMS technique offers the potential for low cost production of high performance metal oxide fibers.; These fibers were shown to be susceptible to attack and eventual dissolution by liquid phase water. The water solubility of CA IMS fibers can provide a solution to health related issues and recycling of matrix materials. With exposure to saturated lime water a limited initial attack took place, which then came to a halt. A layer was formed that is thin, continuous and fine grained, and offered protection in the aqueous environments.; The strong basic nature and favorable mechanical properties of these fibers make them of special interest to the concrete industry, where the strong basic nature of the portland cement matrix suggests compatibility. Composites of Type I portland cement and approximately 14 volume % of CA IMS fibers were molded into compressive test specimens. Considerable enhancement of compressive strengths of the composites (over twice that of matrix alone) was observed, depending on the surface condition of the CA IMS fibers and their arrangement. The presence of a carbon sheath on the fibers from the IMS fibers appeared to reduce the overall strength of the composite compared to oxidized CA IMS fibers.; The chemical and thermal stability of CA IMS fibers with a molten aluminum alloy makes these fibers excellent candidates for reinforcements of metal matrix composites. CA IMS fibers were successfully incorporated into 6061 aluminum alloy with minimal fiber/matrix reaction at the relatively low temperature (940 K). The accumulation of magnesium alloy addition at interphase region enhanced the interfacial wettability. At higher processing temperature (1273 K) a spinel compound, {dollar}rm MgAlsb2Osb4,{dollar} interphase was observed between the CA fiber and aluminum alloy matrix. |
