Coated rotary tool and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-2015209896-A1
Application number	US-201514678254-A
Country	US
Kind code	A1
Filing date	Apr 3, 2015
Priority date	Feb 29, 2012
Publication date	Jul 30, 2015
Grant date	—

Abstract

A friction stir welding tool of the present invention is used for friction stir welding, and includes: a base material; and a coating layer formed on a surface of at least a portion of the base material that is to be caused to contact workpieces during friction stir welding, the base material being formed of a cemented carbide, and the coating layer containing cubic WC 1-x and being formed by electrical discharge machining.

First claim

1 . A friction stir welding tool used for friction stir welding, comprising:
a base material; and a coating layer formed on a surface of at least a portion of said base material that is to be caused to contact workpieces during friction stir welding, said base material being formed of a cemented carbide, and said coating layer containing cubic WC 1-x and being formed by electrical discharge machining, wherein said base material is formed of a cemented carbide having a thermal conductivity of less than 60 W/m·K.

2 . The friction stir welding tool according to claim 1 , wherein said base material contains WC having an average particle size of not less than 0.1 μm and not more than 1 μm.

3 . The friction stir welding tool according to claim 1 , wherein said base material contains not less than 3% by mass and not more than 15% by mass of Co.

4 . The friction stir welding tool according to claim 1 , wherein said coating layer subjected to x-ray diffraction has I (WC 1-x )/I (W 2 C) of not less than 2, where I (WC 1-x ) is a higher one of respective diffracted beam intensities of (111) diffracted beam and (200) diffracted beam, and I (W 2 C) is a highest one of respective diffracted beam intensities of (1000) diffracted beam, (0002) diffracted beam, and (1001) diffracted beam.

5 . The friction stir welding tool according to claim 1 , wherein friction stir welding by means of said friction stir welding tool is spot joining.

6 . The friction stir welding tool according to claim 1 , wherein said coating layer has a surface roughness Ra of not less than 0.05 μm and not more than 0.6 μm.

7 . A method for manufacturing a friction stir welding tool, comprising the step of performing electrical discharge machining on a base material formed of a cemented carbide to simultaneously process said base material and form a coating layer on a surface of at least a portion of said base material that is to be caused to contact workpieces,
said coating layer containing cubic WC 1-x , wherein said base material is formed of a cemented carbide having a thermal conductivity of less than 60 W/m·K.

8 . The friction stir welding tool according to claim 1 , wherein said electrical discharge machining is die-sinker electrical discharge machining.

9 . The friction stir welding tool according to claim 1 , wherein said base material is formed of a cemented carbide having a thermal conductivity of less than 40 W/m·K.

10 . The friction stir welding tool according to claim 1 , wherein said base material contains not less than 6% by mass and not more than 12% by mass of Co.

11 . The friction stir welding tool according to claim 1 , wherein said base material contains WC having an average particle size of not less than 0.2 μm and not more than 0.7 μm.

12 . The method of claim 7 , wherein said electrical discharge machining is die-sinker electrical discharge machining.

13 . The method of claim 7 , wherein a machining rate of said electrical discharge machining is 0.005 to 0.05 g/min.

14 . The method of claim 7 , wherein said electrical discharge machining comprises using an electrode of copper, copper tungsten, silver tungsten, or graphite.

Assignees

• Sumitomo Electric Industries

Inventors

• Utsumi Yoshiharu
• Moriguchi Hideki

Classifications

• B23H5/02

  Electrical discharge machining combined with electrochemical machining · CPC title

• B05D3/002

  Pretreatement · CPC title

• B05D3/14

  by electrical means · CPC title

• B23K20/1255 Primary

  Tools therefor, e.g. characterised by the shape of the probe · CPC title

• C23C30/005

  on hard metal substrates · CPC title