Patent ID: 9334193
Filing Date: 2016-05-10
CPC Classification: C04B,F16C,Y10T

Claim Text:
1. A wear resistant member comprising a ceramic sintered body, the ceramic sintered body comprising: silicon nitride, 10 to 3,500 ppm by mass of a Fe component in terms of Fe element, more than 1,000 ppm up to 2,000 ppm by mass of a Ca component in terms of Ca element, 1 to 2,000 ppm by mass of a Mg component in terms of Mg element, 1 to 5 mass % of a rare earth component in terms of a rare earth element, and 1 to 5 mass % of an Al component in terms of Al element; wherein in the ceramic sintered body: a β-phase ratio of silicon nitride crystal grains is 95% or more, an average aspect ratio, which is defined as an average value of respective aspect ratios of silicon nitride crystal grains, is 2 or more, a maximum longer diameter of the silicon nitride crystal grains in the ceramic sintered body is 40 μm or less, and a grain boundary phase comprises amounts of the Ca component and Mg component that are below a detection limit of XRD (X-ray diffraction); wherein the Ca component and the Mg component have been substantially changed into an amorphous form in the ceramic sintered body, and wherein the ceramic sintered body comprises a ground surface having a surface roughness Ra of 1 μm or less; and wherein the ceramic sintered body has a Vickers hardness of 1,430 or more, a fracture toughness of 6.0 MPa·m wherein the dispersion of the hardness, fracture toughness and density of the wear resistant member is within a range of ±10%.