著者

高岡 勝哉 村瀬 康 加藤 将樹 廣田 健

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.57, no.2, pp.112-117, 2010-02-15

被引用文献数

1 1

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Synthesis of dense composite materials with the compositions of Al<SUB>2</SUB>O<SUB>3</SUB>/Mo<SUB>2</SUB>N=100/0∼40/60 vol% has been attempted directly from Al<SUB>2</SUB>O<SUB>3</SUB>/Mo mixed raw powder compacts using capsule-free N<SUB>2</SUB> hot isostatic pressing (HIP). During HIPing [1500°C/(16∼20-200MPa)/1h], solid/gas reaction between Mo and N<SUB>2</SUB> was introduced to form Mo<SUB>2</SUB>N. The most of sintered composites consisting of only Al<SUB>2</SUB>O<SUB>3</SUB> and Mo<SUB>2</SUB>N phases reached to a higher relative density than 98.0 % with closed pores nevertheless capsule-free HIPing. Dispersion of Mo<SUB>2</SUB>N particles just formed suppressed the grain growth of Al<SUB>2</SUB>O<SUB>3</SUB> during sintering. Mechanical properties, such as bending strength (<I>σ</I><SUB>b</SUB>), Vickers hardness (<I>H</I><SUB>V</SUB>), fracture toughness (<I>K</I><SUB>1C</SUB>), and other properties have been evaluated as a function of their compositions. The best mechanical values of <I>σ</I><SUB>b</SUB> (∼573 MPa), <I>H</I><SUB>V</SUB> (∼20.3 GPa) and <I>K</I><SUB>1C</SUB> (∼5.00 MPa·m<SUP>1/2</SUP>) were attained at the composition of Al<SUB>2</SUB>O<SUB>3</SUB>/Mo<SUB>2</SUB>N=90/10 vol%, due to a high density (98.6 %) and small grain size of Al<SUB>2</SUB>O<SUB>3</SUB> matrix (<I>G</I><SUB>s</SUB>∼4.70 <I>μ</I>m). Further addition of Mo<SUB>2</SUB>N reduced the sinterability of matrix grains, resulting in low densities of around 90 % at the 40/60 vol% composition.