Friction stir welding tool and a method of fabricating the same

Patent metadata

Field	Value
Publication number	US-10016839-B1
Application number	US-201715797359-A
Country	US
Kind code	B1
Filing date	Oct 30, 2017
Priority date	Mar 9, 2017
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A friction stir welding tool comprising a composite of a tungsten-rhenium alloy and hafnium carbide particles, wherein a crystallite size of the tungsten-rhenium alloy is no more than 100 nm, wherein the hafnium carbide particles are dispersed within the tungsten-rhenium alloy, a method of fabricating the friction stir welding tool, and a method of friction stir welding a metal joint using the tool. Various embodiments of the friction stir welding tool, the method of fabricating the tool, and the method of friction stir welding using the tool are provided.

First claim

The invention claimed is:

1. A method of fabricating a composite of a ball-milled tungsten-rhenium alloy and hafnium carbide particles, comprising:
ball-milling a tungsten-rhenium alloy for no more than 25 hours to form a first powder, wherein a concentration of rhenium is in the range of 20 to 30wt %, relative to the total weight of the tungsten-rhenium alloy;
mixing hafnium carbide particles with the first powder to form a second powder, wherein a concentration of hafnium carbide particles in the second powder is in the range of 1 to 15 vol %, relative to the total volume of the second powder;
ball-milling the second powder for no more than 15 hours to form a third powder; and
spark-plasma-sintering the third powder at a temperature of 1500 to 2000° C. for no more than 10 minutes to form the composite of the ball-milled tungsten-rhenium alloy and hafnium carbide particles, wherein the ball-milled hafnium carbide particles are dispersed within the ball-milled tungsten-rhenium alloy, and wherein the ball-milled tungsten-rhenium alloy has a crystallite size of no more than 100 nm.

2. The method of claim 1 , further comprising:
extruding the composite to form a friction stir welding tool that has a tip and a shoulder, wherein the tip has a cylindrical, a conical, a triangular, or a pyramidal geometry.

3. The method of claim 1 , wherein a crystallite size of the ball-milled tungsten-rhenium alloy in the third powder is in the range of 10 to 50 nm.

4. The method of claim 1 , wherein the third powder is compacted with a pressure of 40 to 60 MPa during the spark-plasma-sintering.

5. The method of claim 1 , wherein the tungsten-rhenium alloy is ball-milled in an inert atmosphere with a milling speed of 200 to 300 rpm, wherein a ball-to-powder weight ratio is in the range of 6:1 to 10:1.

6. The method of claim 1 , wherein the second powder is ball-milled in an inert atmosphere with a milling speed of 100 to 200 rpm, wherein a ball-to-powder weight ratio is in the range of 4:1 to 6:1.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Iqbal Zafar
• Shuaib Abdelrahman N
• Merah Necar
• Saheb Nouari

Classifications

• C22C32/0052

  only carbides · CPC title

• C22C1/1084

  by mechanical alloying (blending, milling) · CPC title

• B22F9/04

  starting from solid material, e.g. by crushing, grinding or milling ({C22C1/1084 takes precedence}; crushing, grinding or milling, in general, see the relevant subclasses, e.g. B02C) · CPC title

• B22F9/14

  using electric discharge · CPC title

• B23K20/1255 Primary

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