Research on Microstructure and Properties of Fiber/NiFe2O4 Composite Ceramic

摘要

Powder metallurgy technology and two-step sintering process were used to prepare fiber/NiFe2O4 composite ceramic. The first step was to prepare NiFe2O4 spinel matrix material with NiO, Fe2O3 as the initial materials, and the second was to gain fiber/NiFe2O4 composite ceramic by cold pressing with sintering method taking the first-step product and copperplating carbon fiber as raw materials. X-ray diffusion (XRD) and scanning electron microscope (SEM) were employed to study the impact of copperplating carbon fiber on the microstructure and properties of fiber/NiFe2O4 composite ceramic. The results suggest that fiber/NiFe2O4 composite ceramic sintered at 1300℃ was consisted of ceramic phase and metal phase. With the content of carbon fiber coated by copper increasing, the grain size grew from 3μm to 30μm while the relative density of product from 81.4% to 91.8%, and the fracture mode varied from intergranular fracture to trans-granular fracture.