ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Different Fe-Al2O3 and FeAl-Al2O3 composites with metallic contents up to 30 vol% have been fabricated via reaction processing of Al2O3, Fe, and Al mixtures. Low Al contents (〈∼10 vol%) within the starting mixture lead to composites consisting of Fe embedded in an Al2O3 matrix, whereas aluminide-containing Al2O3 composites result from powder mixtures with higher Al contents. In both cases, densification up to 98% TD can be achieved by pressureless sintering in inert atmosphere at moderate temperatures (1450°-1500°C). The proposed reaction sintering mechanism includes the reduction of native oxide layers on the surface of the Fe particles by Al and, in the case of mixtures with high Al contents, aluminide formation followed by sintering of the composites. Density and bending strengths of the reaction-sintered composites depend strongly on the Al content of the starting mixture. In the case of samples containing elemental Fe, crack path observations indicate the potential for an increase of fracture toughness, even at room temperature, by crack bridging of the ductile Fe inclusions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1151-2916.1997.tb03120.x
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