放電プラズマ焼結法によるAl_2O_3-cBN傾斜材料の作製 Preparation of Al_2O_3-cBN Functionally Graded Material by Spark Plasma Sintering
Al<SUB>2</SUB>O<SUB>3</SUB>-cBN functionally graded material (FGM) was synthesized by spark plasma sintering (SPS) using powder compact with graded compositions containing 0 to 20 vol% cBN under a uniaxial pressure of 100 MPa. Densification, phase transformation of cBN, microstructure, hardness and fracture toughness of the FGM were investigated. Al<SUB>2</SUB>O<SUB>3</SUB>-cBN FGM with relative density of more than 99% was prepared at 1300°C for 600 s. No obvious interface between Al<SUB>2</SUB>O<SUB>3</SUB> and cBN layers was observed, and cBN particles were uniformly dispersed in an Al<SUB>2</SUB>O<SUB>3</SUB> matrix. Vickers hardness and fracture toughness continuously increased with cBN content, and reached to 28 GPa and 5 MPa·m<SUP>1/2</SUP> respectively at the surface layer.
粉体および粉末冶金 55(5), 373-377, 2008-05-15
Japan Society of Powder and Powder Metallurgy