Patent ID: 8133830

Claim:
A sliding member comprising: a silicon nitride sintered compact containing silicon nitride grains, and a sintering aid component in a range of not less than 2 mass % and not more than 15 mass %, wherein the silicon nitride grains include needle crystal grains each having a long diameter L of 10 μm or less and a ratio of the long diameter L to a short diameter S (L/S) of 5 or more, wherein an area ratio of the needle crystal grains in a crystalline structure of the silicon nitride sintered compact is in a range of not less than 50% and not more than 80%, wherein a maximum diameter of voids existing in the silicon nitride sintered compact is 3 μm or less, wherein a number of the voids is five or less in a region of 30×30 μm, and wherein the sliding member is a bearing ball.