WO1998056528A1 - Method of making endmills - Google Patents

Method of making endmills Download PDF

Info

Publication number
WO1998056528A1
WO1998056528A1 PCT/SE1998/001113 SE9801113W WO9856528A1 WO 1998056528 A1 WO1998056528 A1 WO 1998056528A1 SE 9801113 W SE9801113 W SE 9801113W WO 9856528 A1 WO9856528 A1 WO 9856528A1
Authority
WO
WIPO (PCT)
Prior art keywords
cbn
shank
endmill
cemented carbide
tenon
Prior art date
Application number
PCT/SE1998/001113
Other languages
French (fr)
Inventor
Peter Littecke
Original Assignee
Sandvik Ab
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sandvik Ab filed Critical Sandvik Ab
Priority to JP50229099A priority Critical patent/JP2002504027A/en
Priority to EP98929975A priority patent/EP0988125A1/en
Priority to CA002290023A priority patent/CA2290023A1/en
Priority to KR19997011706A priority patent/KR20010013691A/en
Publication of WO1998056528A1 publication Critical patent/WO1998056528A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C5/00—Milling-cutters
    • B23C5/02—Milling-cutters characterised by the shape of the cutter
    • B23C5/10—Shank-type cutters, i.e. with an integral shaft
    • B23C5/1081—Shank-type cutters, i.e. with an integral shaft with permanently fixed cutting inserts 
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C5/00—Milling-cutters
    • B23C5/02—Milling-cutters characterised by the shape of the cutter
    • B23C5/10—Shank-type cutters, i.e. with an integral shaft
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C5/00—Milling-cutters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
    • B23P15/28—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass cutting tools
    • B23P15/34—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass cutting tools milling cutters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C2226/00—Materials of tools or workpieces not comprising a metal
    • B23C2226/12—Boron nitride
    • B23C2226/125—Boron nitride cubic [CBN]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C2226/00—Materials of tools or workpieces not comprising a metal
    • B23C2226/31—Diamond
    • B23C2226/315—Diamond polycrystalline [PCD]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C2240/00—Details of connections of tools or workpieces
    • B23C2240/08—Brazed connections

Definitions

  • This invention relates to an endmill with cBN (cubic boron nitride) or PCD (polycrystalline diamond) in the cutting edges and a method of making the same.
  • the purpose of the method is to decrease the cost compared to existing methods.
  • An endmill is used for machining of grooves, pockets and slots and consists of a cylindrical holder with cutting means at the end. It can be made of high speed steel, or solid cemented carbide, but it can also consist of a steel holder with cemented carbide inserts as cutting means .
  • metal cutting inserts having cutting edges formed of a superhard material, such as PCD are usually used for the machining of non-ferrous alloys such as brass, magnesium and aluminium, and the like, whereas inserts with cutting edges formed of a superhard abrasive, such as cBN are usually used for the machining of cast iron and hardened steel and the like.
  • PCD or cBN endmills there are several types of PCD or cBN endmills on the market today. Essentially there are two different methods to manufacture them. One method includes sintering cBN or diamond powder under elevated pressure and temperature into a solid cylindrical body which is then brazed onto a shank and finished into an endmill . The other method includes bonding a layer of cBN or diamond under elevated pressure and temperature to a substrate, usually a cemented carbide disc, from which smaller pieces, "chips", are cut out. These chips are then brazed onto a cemented carbide rod and ground to the finished shape. Tools produced that way are normally quite expensive due to the many steps the product must undergo before it is finished.
  • the object of the present invention is therefore to provide a method, where an endmill with several cutting edges can be achieved but at a substantially lower cost.
  • Fig 1 shows the principle of the method where 1 is the element that will form the cutting part,
  • FIG. 5 is a top view of the element 1 after shaping to expose the cutting edges.
  • the starting point is a cemented carbide disc preferably with a binder phase content of >10 wt-% provided with superhard bodies according to the teachings of US 5,676,496.
  • the cemented carbide disc is made from a cemented carbide rod with a circular, square, triangular or other suitable cross section preferably with a center hole.
  • This rod one or more grooves are ground throughout its whole length and parallel to its axis.
  • the groove can be straight but it can also be helical.
  • the number of grooves and their location depend on the type of disc that is to be produced.
  • the shape of the grooves can be made in different ways. It is important, however, that they have a rounded or plane shape. Their size shall be such that the cutting work essentially is performed by the superhard material . After HP/HT sintering the rod is cut into discs of desired thickness .
  • cemented carbide discs at least one groove is ground and filled with a powder mixture containing cBN and/or diamond after which the discs are treated at a temperature and pressure where cBN and/or diamond is stable. During this treatment the discs are separated from each other in such a way that they do not sinter together.
  • the shank 2 is preferably made in cemented carbide preferably with a binder phase content of >10 wt-%. The diameter of the shank is somewhat smaller than the diameter of the disc with superhard materials . The other end of the shank is provided with clamping means .
  • the PCD/cBN disc is then brazed together with the shank .
  • the end of the shank where the PCD/cBN disc is brazed is ground down to form a tenon, 4.
  • the shape of the tenon is generally cylindrical but it may alternatively be tapered, square, triangular, elliptical or other non-round shape.
  • the diameter (or equivalent) of the tenon is about 15 - 40 % of the diameter of the shank and is designed to fit within the center hole of the disc 1 although the tenon does not have to extend through the entire length of that center hole.
  • the PCD/cBN disc is then brazed together with the shank using the tenon as guide and braze joint, 3. It is according to the invention essential that brazing is made only at the tenon. This will minimise the risk of braze joint failure.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Earth Drilling (AREA)
  • Drilling Tools (AREA)
  • Cutting Tools, Boring Holders, And Turrets (AREA)

Abstract

The present invention relates to an endmill provided with cutting edges of cBN or PCD and consisting of a shank part and a part containing the cBN or PCD brazed to the shank. The latter part is in the form of a disc in which the superhard material is present in a groove in the envelope surface and extends from one end surface to the other. After brazing the disc to the shank, the body obtained is ground to an endmill with cutting edges formed of superhard material. In a preferred embodiment, the shank is provided with a tenon against which the part containing the superhard material is brazed. This minimises the risk of braze joint failure and provides an endmill with several cutting edges which can be achieved at a low cost.

Description

Method of making endmills
This invention relates to an endmill with cBN (cubic boron nitride) or PCD (polycrystalline diamond) in the cutting edges and a method of making the same. The purpose of the method is to decrease the cost compared to existing methods.
An endmill is used for machining of grooves, pockets and slots and consists of a cylindrical holder with cutting means at the end. It can be made of high speed steel, or solid cemented carbide, but it can also consist of a steel holder with cemented carbide inserts as cutting means . For certain applications metal cutting inserts having cutting edges formed of a superhard material, such as PCD, are usually used for the machining of non-ferrous alloys such as brass, magnesium and aluminium, and the like, whereas inserts with cutting edges formed of a superhard abrasive, such as cBN are usually used for the machining of cast iron and hardened steel and the like.
There are several types of PCD or cBN endmills on the market today. Essentially there are two different methods to manufacture them. One method includes sintering cBN or diamond powder under elevated pressure and temperature into a solid cylindrical body which is then brazed onto a shank and finished into an endmill . The other method includes bonding a layer of cBN or diamond under elevated pressure and temperature to a substrate, usually a cemented carbide disc, from which smaller pieces, "chips", are cut out. These chips are then brazed onto a cemented carbide rod and ground to the finished shape. Tools produced that way are normally quite expensive due to the many steps the product must undergo before it is finished.
CONFIRMATION COPY The object of the present invention is therefore to provide a method, where an endmill with several cutting edges can be achieved but at a substantially lower cost. Fig 1 shows the principle of the method where 1 is the element that will form the cutting part,
2 is the shank
3 is the braze joint and
4 is a tenon
5 is a top view of the element 1 after shaping to expose the cutting edges.
According to the method of the present invention the starting point is a cemented carbide disc preferably with a binder phase content of >10 wt-% provided with superhard bodies according to the teachings of US 5,676,496. The cemented carbide disc is made from a cemented carbide rod with a circular, square, triangular or other suitable cross section preferably with a center hole. Into this rod one or more grooves are ground throughout its whole length and parallel to its axis. The groove can be straight but it can also be helical. The number of grooves and their location depend on the type of disc that is to be produced. The shape of the grooves can be made in different ways. It is important, however, that they have a rounded or plane shape. Their size shall be such that the cutting work essentially is performed by the superhard material . After HP/HT sintering the rod is cut into discs of desired thickness .
Alternatively, in one or more cemented carbide discs at least one groove is ground and filled with a powder mixture containing cBN and/or diamond after which the discs are treated at a temperature and pressure where cBN and/or diamond is stable. During this treatment the discs are separated from each other in such a way that they do not sinter together. The shank 2 is preferably made in cemented carbide preferably with a binder phase content of >10 wt-%. The diameter of the shank is somewhat smaller than the diameter of the disc with superhard materials . The other end of the shank is provided with clamping means .
The PCD/cBN disc is then brazed together with the shank .
In a preferred embodiment the end of the shank where the PCD/cBN disc is brazed is ground down to form a tenon, 4. The shape of the tenon is generally cylindrical but it may alternatively be tapered, square, triangular, elliptical or other non-round shape. The diameter (or equivalent) of the tenon is about 15 - 40 % of the diameter of the shank and is designed to fit within the center hole of the disc 1 although the tenon does not have to extend through the entire length of that center hole.
The PCD/cBN disc is then brazed together with the shank using the tenon as guide and braze joint, 3. It is according to the invention essential that brazing is made only at the tenon. This will minimise the risk of braze joint failure.
After brazing the tool obtained is ground in such a way that cutting edges are formed from the superhard bodies as shown in the top view 5 of Fig 1.

Claims

Claims
1. Endmill provided with cutting edges of cBN or PCD and consisting of a shank part and a part containing the cBN or PCD brazed to the shank c h a r a c t e r i s e d in that said shank is provided with a tenon against which the part containing the superhard material is brazed.
2. Endmill according to the preceding claim c h a r a c t e r i s e d in that said tenon is round.
3. Endmill according to claim 1 c h a r a c t e r i s e d in that said tenon is tapered.
4. Endmill according to claim 1 c h a r a c t e r i s e d in that said tenon is of non- round shape .
5. Endmill according to claim 1 c h a r a c t e r i s e d in that said tenon extends at least part way into the part containing the superhard material .
6. Method of making an endmill provided with at least one cutting edge of cBN or PCD and consisting of a shank part and a part containing the cBN or PCD c h a r a c t e r i s e d in comprising the steps providing a cemented carbide disc preferably with a cylindrical cross section provided with at least one body of a superhard material in a groove in the envelope surface and extending from one end surface to the other brazing said cemented carbide disc to a shank grinding the obtained body to form an endmill with cutting edges formed from the superhard material .
7. Method according to claim 6 c h a r a c t e r i s e d in that said cemented carbide disc is made using the following steps providing a cemented carbide bar grinding at least one groove in said bar filling said groove with a powder mixture containing cBN and/or diamond heat treating said cemented carbide bar at a temperature and pressure where cBN and/or diamond is stable and cutting said bar into discs.
8. Method according to claim 6 c h a r a c t e r i s e d in said cemented carbide disc is made using the following steps providing one or more cemented carbide discs grinding at least one groove in said discs filling said groove in said discs with a powder mixture containing cBN and/or diamond heat treating said cemented carbide discs at a temperature and pressure where cBN and/or diamond is stable whereby the discs are separated from each other in such a way that they do not sinter together.
9. Method according to any of claims 6 - 8 c h a r a c t e r i s e d in the step of brazing said shank part to the part containing the superhard material with the aid of a tenon formed in the end of said shank part and a hole extending at least partway through said part containing the superhard material .
10. The product according to any of claims 6 - 8.
PCT/SE1998/001113 1997-06-13 1998-06-10 Method of making endmills WO1998056528A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP50229099A JP2002504027A (en) 1997-06-13 1998-06-10 End mill manufacturing method
EP98929975A EP0988125A1 (en) 1997-06-13 1998-06-10 Method of making endmills
CA002290023A CA2290023A1 (en) 1997-06-13 1998-06-10 Method of making endmills
KR19997011706A KR20010013691A (en) 1997-06-13 1998-06-10 Method of making endmills

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9702297-4 1997-06-13
SE9702297A SE512752C2 (en) 1997-06-13 1997-06-13 Ways to make stick cutters

Publications (1)

Publication Number Publication Date
WO1998056528A1 true WO1998056528A1 (en) 1998-12-17

Family

ID=20407402

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1998/001113 WO1998056528A1 (en) 1997-06-13 1998-06-10 Method of making endmills

Country Status (8)

Country Link
EP (1) EP0988125A1 (en)
JP (1) JP2002504027A (en)
KR (1) KR20010013691A (en)
CN (1) CN1260742A (en)
CA (1) CA2290023A1 (en)
SE (1) SE512752C2 (en)
WO (1) WO1998056528A1 (en)
ZA (1) ZA985147B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2892326A1 (en) * 2005-10-24 2007-04-27 Sofdiam Soc Par Actions Simpli Hard material e.g. infonel, cutter for forming chamfer on rivet of airplane wing, has support and monoblock cutting tip integrated with each other by brazing and respectively made of basis steel and carbide
WO2015198361A1 (en) * 2014-06-23 2015-12-30 Sumitomo Electric Hardmetal Corp. Cutting tool and method of manufacturing a cutting tool
CN105458641A (en) * 2016-01-06 2016-04-06 倍兹（上海）精密刀具有限公司 Manufacturing method for integral PCD cutters applied to small-diameter hole manufacturing

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100423006B1 (en) * 2001-07-18 2004-03-12 프리시젼다이아몬드 주식회사 A blade manufactureing method of a ball cutter and the blade thereof
DE10159431B4 (en) * 2001-12-04 2005-10-20 Mapal Fab Praezision Tool for finishing surfaces
WO2011084864A2 (en) * 2009-12-31 2011-07-14 Diamond Innovations, Inc. Machining tool blank
CN107952986A (en) * 2016-10-17 2018-04-24 上海精韧激光科技有限公司 For manufacturing the blank and its manufacture method of cutting element
CN108262495A (en) * 2016-12-31 2018-07-10 上海名古屋精密工具股份有限公司 For the blank and its manufacturing method of ultra-hard cutting tool manufacture
KR102249490B1 (en) * 2019-10-18 2021-05-12 한국오에스지 주식회사 Structure of insert for ball end mill

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0458434A2 (en) * 1990-05-24 1991-11-27 Smith International, Inc. Rotary cutter with Diamond-like cutting edges
EP0744242A2 (en) * 1995-05-22 1996-11-27 Sandvik Aktiebolag Metal cutting inserts having superhard abrasive bodies and methods of making same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0458434A2 (en) * 1990-05-24 1991-11-27 Smith International, Inc. Rotary cutter with Diamond-like cutting edges
EP0744242A2 (en) * 1995-05-22 1996-11-27 Sandvik Aktiebolag Metal cutting inserts having superhard abrasive bodies and methods of making same

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2892326A1 (en) * 2005-10-24 2007-04-27 Sofdiam Soc Par Actions Simpli Hard material e.g. infonel, cutter for forming chamfer on rivet of airplane wing, has support and monoblock cutting tip integrated with each other by brazing and respectively made of basis steel and carbide
WO2015198361A1 (en) * 2014-06-23 2015-12-30 Sumitomo Electric Hardmetal Corp. Cutting tool and method of manufacturing a cutting tool
CN106573314A (en) * 2014-06-23 2017-04-19 住友电工硬质合金株式会社 Cutting tool and method of manufacturing a cutting tool
US10040126B2 (en) 2014-06-23 2018-08-07 Sumitomo Electric Hardmetal Corp. Cutting tool and method of manufacturing a cutting tool
CN105458641A (en) * 2016-01-06 2016-04-06 倍兹（上海）精密刀具有限公司 Manufacturing method for integral PCD cutters applied to small-diameter hole manufacturing

Also Published As

Publication number Publication date
CA2290023A1 (en) 1998-12-17
SE9702297D0 (en) 1997-06-13
EP0988125A1 (en) 2000-03-29
SE512752C2 (en) 2000-05-08
KR20010013691A (en) 2001-02-26
JP2002504027A (en) 2002-02-05
SE9702297L (en) 1998-12-14
ZA985147B (en) 1999-01-20
CN1260742A (en) 2000-07-19

Similar Documents

Publication Publication Date Title
US5676496A (en) Metal cutting inserts having superhard abrasive bodies and methods of making same
US7189032B2 (en) Tool insert
US6447560B2 (en) Method for forming a superabrasive polycrystalline cutting tool with an integral chipbreaker feature
CA1254451A (en) Polycrystalline diamond and cbn cutting tools
US6159286A (en) Process for controlling diamond nucleation during diamond synthesis
US20050271483A1 (en) Indexable cutting inserts and methods for producing the same
KR100383715B1 (en) Metal cutting inserts having superhard abrasive bodies and methods of making same
EP0480895A2 (en) Improved diamond tools for rock drilling, metal cutting and wear part applications
JPH0348315B2 (en)
JPH11309609A (en) Polycrystalline diamond tool
EP0941791B1 (en) Abrasive body
US5486072A (en) Cutting tools of composite construction
JP2001519722A (en) Machine tool and manufacturing method thereof
WO1998056528A1 (en) Method of making endmills
JPH0373210A (en) High hardness cutting tool and manufacture and use thereof
JPH08336716A (en) Rotary cutting tool
US4295885A (en) Material and method for securing boron filaments to each other and to a substrate and cutting tools therefrom
EP0206652B1 (en) A method of making a blank of a drill bit
US4116689A (en) Material and method for securing boron filaments to each other and to a substrate and cutting tools therefrom
US20080131304A1 (en) Endmills
JPH11504868A (en) Central cutting end mill with flute made of diamond or cBN
EP0220964B1 (en) Cubic boron nitride abrasive bodies
JP2004268202A (en) Small diameter end mill
JP2008538536A5 (en)
JP2000190108A (en) Polycrystalline hard sintered body cutting tool

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 98806156.2

Country of ref document: CN

AK Designated states

Kind code of ref document: A1

Designated state(s): BR CA CN JP KR RU

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
ENP Entry into the national phase

Ref document number: 2290023

Country of ref document: CA

Ref document number: 2290023

Country of ref document: CA

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 1998929975

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 1019997011706

Country of ref document: KR

WWP Wipo information: published in national office

Ref document number: 1998929975

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1019997011706

Country of ref document: KR

WWW Wipo information: withdrawn in national office

Ref document number: 1998929975

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1019997011706

Country of ref document: KR