Title:
FREE CUTTING CERAMIC AND ITS MANUFACTURING
Document Type and Number:
Japanese Patent JP3890915
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To manufacture a low thermal expansive free cutting ceramic having excellent machineability and high strength by firing in atmospheric pressure.
SOLUTION: Silicon nitride powder containing silicon oxide of 0.5 to 10 mass%, the mean grain diameter of which is ≤5 μm, and boron nitride powder containing boron oxide of 2 to 15 mass%, the grain diameter of which is ≤0.5 μm are mixed at a ratio of 40 to 85 mass% silicon nitride part to 15 to 60 mass% boron nitride part, then, 15 to 31 mass% sintering aide based on the sum of silicon nitride, boron nitride and sintering aid is mixed thereto, then, the obtained mixed powder is press formed, and fired in an inert gas of atmospheric pressure. The free cutting ceramic has ≥200 MPa bending stress, ≤4×10-6/°C thermal expansion coefficient at 25 to 300°C, cutting speed of 18 m/min using carbide tool of K-10 and abrasion width of major flank of cutting tool of ≤0.2 mm in the turning test for 5 min. under the condition that feeding speed is 0.03 mm/rev. and cutting is 0.1 mm.
Inventors:
Shunichi Eto
Arahori Tadahisa
Yasuki Yoshitomi
Kuniaki Nakagawa
Arahori Tadahisa
Yasuki Yoshitomi
Kuniaki Nakagawa
Application Number:
JP2001106053A
Publication Date:
March 07, 2007
Filing Date:
April 04, 2001
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
C04B35/584; C04B35/583; (IPC1-7): C04B35/584
Domestic Patent References:
| JP2000327402A | ||||
| JP4026550A | ||||
| JP4026552A |
Attorney, Agent or Firm:
Shoichi Hirose