Title:
CEMENTED CARBIDE WITH IMPROVED TOUGHNESS
Document Type and Number:
WIPO Patent Application WO/2016/108421
Kind Code:
A1
Abstract:
The present invention relates to a cemented carbide for a cutting tool, which allows uniform formation of a Co tissue within a cubic phase free layer (CFL) formed in a cemented carbide, without forming a non-uniform coarse tissue, so that wear resistance and excellent impact resistance can be obtained when a high-hardness film is formed on the upper part thereof, and thus can be adequately used in high speed transfer and high speed machining. The cutting tool according to the present invention comprises a cemented carbide which comprises: a particle mainly composed of tungsten carbide (WC); a binder phase mainly composed of Co; and a particle comprising at least one carbide or carbonitride selected from the group consisting of elements of groups 4a, 5a and 6a, or a solid solution thereof, wherein a CFL having no carbide or carbonitride formed thereon is formed up to 5 to 50 µm from the surface toward the inside of the cemented carbide, and wherein when the core part to the surface of the CFL is regarded as the upper part of the CFL, the core part of the CFL to the boundary part of the lower part of a matrix is regarded as the lower part of the CFL, and the major axis length of the Co tissue formed on the CFL having a major axis length to minor axis length ratio of 5 or less is regarded as the size of the Co tissue, the maximum size of the Co tissue within the lower part of the CFL is at most 2 times the maximum size of the Co tissue within the upper part.
Inventors:
KIM JUNG-WOOK (KR)
LEE SUNG-GU (KR)
KIM YONG-HYUN (KR)
AHN SUN-YONG (KR)
LEE SUNG-GU (KR)
KIM YONG-HYUN (KR)
AHN SUN-YONG (KR)
Application Number:
PCT/KR2015/012055
Publication Date:
July 07, 2016
Filing Date:
November 10, 2015
Export Citation:
Assignee:
KORLOY INC (KR)
International Classes:
C22C29/08; C22C19/07
Foreign References:
| JP2006021316A | 2006-01-26 | |||
| KR20050110822A | 2005-11-24 | |||
| KR20000057904A | 2000-09-25 | |||
| KR20110100621A | 2011-09-14 | |||
| KR20090023383A | 2009-03-04 |
Attorney, Agent or Firm:
IAM PATNET FIRM (KR)
특허법인 아이엠 (KR)
특허법인 아이엠 (KR)
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