アルミナ/モリブデンナノ複合材料の特性評価(<特集>セラミック材料)

概要

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We fabricated alumina/molybdenum (Mo) nanocomposites. To prepare very fine Mo powder, molybdenum oxide (MoO_3) powder was dissolved in 28% ammonia solution. Alumina powder was then mixed with the neutralized MoO3 solution in ethanol using a ball mill. After drying, a pulse electric current sintering method was used for sintering the mixed powder at 30MPa for 5min in vacuum in the temperatures ranging from 1250℃ to 1550℃. Three-point bending and fracture toughness (SEVNB) tests were carried out on the specimens of 2×2×10mm in size. The results showed that the maximum values of the fracture strength and the fracture toughness were 860MPa and 5.22MPa\m^<1/2> for the specimens sintered at 1450℃, respectively. The specimens with the highest fracture toughness were then annealed at 800℃, 900℃, and 1000℃ from 0 to 10min. The fracture toughness of the specimen annealed at 800℃ for 10min increased from 5.22 to 5.67MPa・m^<1/2>. The strengthening and toughening mechanisms of the alumina-Mo nanocomposites were discussed with emphasis on dislocation activities.
社団法人日本材料学会の論文
2006-07-15