Processing and characterization of alumina wire by controlled fracture forming process: (II) Resintering behavior and mechanical properties

The resintering behavior of the CS-Al2O3 wire, and its mechanical propertie s with respect to the Vickers hardness and the tensile strength has been in vestigated. Results indicate that the CS-98 wire can be fully densified wit hout abnormal grain growth. The improved densification is attributed to the crushed constituent particles with new surfaces accelerating the matter di ffusion. The retardation of grain growth is attributed to the homogeneously distributed pores in the green microstructure, which act the drag forces o n grain boundary migration. The fracture mode of the resintered wire shows to be dependent on the residual pores, viz. the transgranular fracture is d ominant at porosity < 2%, whereas the intergranular becomes controlling at porosity > 2%. The distribution of the Vickers hardness on the cross-sectio nal surface of the Al2O3 core in the resintered Al2O3/SUS 304 composite wir e indicates that the sheath material has a significant influence on the mec hanical properties of the core. (C) 2001 Elsevier Science B.V. All rights r eserved.