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 properties with respect to the Vickers hardness and the tensile strength has been investigated. Results indicate that the CS-98 wire can be fully densified without abnormal grain growth. The improved densification is attributed to the crushed constituent particles with new surfaces accelerating the matter diffusion. The retardation of grain growth is attributed to the homogeneously distributed pores in the green microstructure, which act the drag forces on grain boundary migration. The fracture mode of the resintered wire shows to be dependent on the residual pores, viz. the transgranular fracture is dominant at porosity < 2%, whereas the intergranular becomes controlling at porosity > 2%. The distribution of the Vickers hardness on the cross-sectional surface of the Al₂O₃ core in the resintered Al₂O₃/SUS 304 composite wire indicates that the sheath material has a significant influence on the mechanical properties of the core.