A method for cutting refractory metals

Patent metadata

Field	Value
Publication number	US-2020055157-A1
Application number	US-201716476497-A
Country	US
Kind code	A1
Filing date	Nov 20, 2017
Priority date	Jan 10, 2017
Publication date	Feb 20, 2020
Grant date	—

Abstract

The invention relates to a method for cutting refractory metals, in which a solid body ( 1 ) made of a refractory metal is mechanically machining cut with a cutting apparatus ( 4, 7 ), wherein the cutting apparatus ( 4, 7 ) is wetted for cutting with a fluid ( 6 ) having at least 50 weight % water, wherein the cutting apparatus ( 4, 7 ) is brought to a positive electrical potential in relation to the solid body ( 1 ) during cutting. The invention also relates to a disc produced from a refractory metal using such a method, and such a disc that has an oxide layer with a thickness of between 2 nm and 1,000 nm on the cutting surface.

First claim

1 . A method for cutting refractory metals, in which a solid body made of a refractory metal is mechanically machining cut with a cutting apparatus, wherein the cutting apparatus is wetted for cutting with a fluid having at least 50 weight % water, wherein the cutting apparatus is brought to a positive electrical potential in relation to the solid body during cutting.

2 . The method of claim 1 , wherein the cutting surface of the solid body is oxidized on the surface by the positive electrical potential of the cutting apparatus in relation to the solid body and by the aqueous fluid, so that an oxide layer forms on the cutting surface during cutting, wherein preferably an amorphous oxide layer forms on the cutting surface.

3 . The method of claim 2 , wherein due to the oxide layer formed during cutting, an absorption of hydrogen and oxygen through the oxide layer into the interior of the solid body is reduced or prevented, wherein the absorption of nitrogen and/or carbon and/or other gases through the oxide layer into the interior of the solid body is preferably also reduced or prevented.

4 . The method of claim 1 , wherein as a cutting apparatus, a blade of a saw device is used, preferably a wire of a wire saw, a thread of a thread saw, a band of a band saw, a saw blade of a hacksaw, a circular saw blade of a circular saw or a cutting disc is used, wherein in a particularly preferred manner, the wire saw or the thread saw is used.

5 . The method of claim 1 , wherein as a cutting apparatus, a wire of a wire saw or a thread of a thread saw is used, and as the fluid, an aqueous sludge is used, in which grinding particles are distributed, wherein the grinding particles are preferably selected from quartz particles, tungsten carbide particles and diamond particles or mixtures of these.

6 . The method of claim 1 , wherein the solid body is crystalline, preferably granular crystalline or monocrystalline.

7 . The method of claim 1 , wherein between the solid body and the cutting apparatus, an electrical voltage of at least 1 V is applied during cutting, preferably an electrical voltage of between 5 V and 200 V is applied.

8 . The method of claim 1 , wherein the cutting apparatus is brought to an electrically positive potential in relation to ground, wherein the solid body is preferably brought to ground potential.

9 . The method of claim 1 , wherein the solid body consists of a refractory metal from the main chemical group IVb, Vb or VIb, or the solid body consists of titanium, tantalum, niobium, vanadium, zirconium, molybdenum or tungsten, wherein titanium, tantalum, niobium and zirconium are particularly preferred and niobium is very particularly preferred.

10 . The method of claim 1 , wherein the solid body is positioned in a bath of the aqueous fluid during cutting, and the cutting apparatus is guided at least partially through the bath during cutting.

11 . The method of claim 2 , wherein the oxide layer on the surface of the cut disc is removed by pickling after cutting.

12 . A disc produced from a refractory metal with a method according to claim 1 .

13 . A disc produced from a refractory metal with a method according to claim 1 , wherein the disc has an oxide layer on the cutting surface with a thickness of between 2 nm and 1,000 nm, preferably between 10 nm and 500 nm.

14 . The disc of claim 13 , wherein the disc has an amorphous oxide layer on the cutting surface.

15 . The disc according of claim 13 , wherein the interior of the disc has an oxygen content of less than 20 μg/g, preferably of less than 10 μg/g, and/or the interior of the disc has a hydrogen content of less than 10 μg/g, preferably less than 3 μg/g.

16 . The disc of claim 12 , wherein the interior of the disc has an oxygen content of less than 20 μg/g, preferably of less than 10 μg/g, and/or the interior of the disc has a hydrogen content of less than 10 μg/g, preferably less than 3 μg/g.

Assignees

• Heraeus Deutschland Gmbh & Co Kg

Inventors

• Schölz Friedhold
• Stiedl Egbert
• Spaniol Bernd
• Traeger Norbert
• Feuring Werner

Classifications

• C22B34/24 Primary

  Obtaining niobium or tantalum · CPC title

• B23Q11/1061 Primary

  using cutting liquids with specially selected composition or state of aggregation · CPC title

• C22C27/02

  Alloys based on vanadium, niobium, or tantalum · CPC title

• B23D59/02

  Devices for lubricating or cooling circular saw blades · CPC title

• B23D57/003

  Sawing machines or sawing devices working with saw wires, characterised only by constructional features of particular parts (constructional features of these parts per se B23Q) · CPC title