Friction Stir Welding for a Nuclear Fusion Reactor

2014 ◽  
Vol 783-786 ◽  
pp. 1808-1813
Author(s):  
Zak Pramann ◽  
Brian Thompson ◽  
Jim Chrzanowski ◽  
Dave Mennel
Keyword(s):  
Friction Stir Welding ◽  
Copper Alloy ◽  
Fusion Reactor ◽  
Nuclear Fusion ◽  
High Strength ◽  
Spherical Torus ◽  
Nuclear Fusion Reactor ◽  
Friction Stir ◽  
The U.S ◽  
State Nature

During a recent upgrade to the U.S. Department of Energy’s Princeton Plasma Physics Laboratory operates an experimental nuclear fusion reactor known as the National Spherical Torus Experiment (NSTX) a new center stack design was selected that required an innovative joining method to fabricate the bundled copper extrusions found in the center stack. Each of the 20-ft long copper extrusions used in the center stack was made from a quarter hard copper alloy (CDA10700) joined to lead extensions made from a high-strength copper alloy (CDA 18150). A team consisting of PPPL, Major Tool, and EWI selected Friction Stir Welding (FSW) to join these two materials together as its solid-state nature would provide a higher joint efficiency while minimizing distortion and preserving properties of the heat treatable lead extension flag.

Fast interplanetary propulsion using a spherical torus nuclear fusion reactor propulsion system

1999 ◽  
Author(s):  
Craig Williams ◽  
Stanley Borowski ◽  
Leonard Dudzinski ◽  
Albert Juhasz
Keyword(s):  
Fusion Reactor ◽  
Nuclear Fusion ◽  
Propulsion System ◽  
Spherical Torus ◽  
Nuclear Fusion Reactor

Study of the Key Issues of Friction Stir Welding of Titanium Alloy

2010 ◽  
Vol 638-642 ◽  
pp. 1185-1190 ◽  
Author(s):  
Hui Jie Liu ◽  
Li Zhou ◽  
Yong Xian Huang ◽  
Qi Wei Liu
Keyword(s):  
Titanium Alloy ◽  
Friction Stir Welding ◽  
Melting Point ◽  
Titanium Alloys ◽  
Welding Process ◽  
High Strength ◽  
Liquid Cooling ◽  
Friction Stir ◽  
Key Issues ◽  
Aluminum And Magnesium Alloys

As a new solid-state welding process, friction stir welding (FSW) has been successfully used for joining low melting point materials such as aluminum and magnesium alloys, but the FSW of high melting point materials such as steels and titanium alloys is still difficult to carry out because of their strict requirements for the FSW tool. Especially for the FSW of titanium alloys, some key technological issues need to solve further. In order to accomplish the FSW of titanium alloys, a specially designed tool system was made. The system was composed of W-Re pin tool, liquid cooling holder and shielding gas shroud. Prior to FSW, the Ti-6Al-4V alloy plates were thermo-hydrogen processed to reduce the deformation resistance and tool wear during the FSW. Based on this, the thermo-hydrogen processed Ti-6Al-4V alloy with different hydrogen content was friction stir welded, and the microstructural characterizations and mechanical properties of the joints were studied. Experimental results showed that the designed tool system can fulfill the requirements of the FSW of titanium alloys, and excellent weld formation and high-strength joint have been obtained from the titanium alloy plates.

Effect of plasma preheating on weld quality and tool life during friction stir welding of DH36 steel

2021 ◽  
pp. 095440542199013
Author(s):  
Avinish Tiwari ◽  
Pardeep Pankaj ◽  
Saurav Suman ◽  
Piyush Singh ◽  
Pankaj Biswas ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Tool Life ◽  
Force Measurement ◽  
Deep Understanding ◽  
High Strength ◽  
Microstructural Characterization ◽  
Stir Zone ◽  
Friction Stir ◽  
Allotriomorphic Ferrite ◽  
Fsw Parameters

Friction stir welding (FSW) of high strength materials is challenging due to high tool cost and low tool life. To address this issue, the present investigation deals with an alternative of plasma-assisted friction stir welding (PFSW) of DH36 steel with WC-10%Co tool. Plasma preheating current (13 A, 15 A, and 17 A) was varied by keeping other FSW parameters as constant. During the FSW and PFSW process, force measurement and thermal history aided in a deep understanding of the process, tool degradation mechanisms, accompanied by the mechanical and microstructural characterization of the welded joints. The stir zone hardness was increased from 140 HV0.5 to about 267 HV0.5. The yield and tensile strength of weld increased from 385 MPa and 514 MPa to about 391 MPa and 539 MPa, respectively. Weld joint elongation (%) was increased from ~10% of weld 1 to ~13.89% of weld 4. During PFSW, the process temperature was increased, the cooling rate was lowered, and the weld bead was widened. The results also revealed that the plasma-assisted weld resulted in polygonal ([Formula: see text]) and allotriomorphic ferrite as the major constituents in the stir zone. Pearlite dissolution and spheroidization were observed in the ICHAZ and SCHAZ, respectively. Additionally, the plasma preheating reduced the tungsten tool’s wear by 58% compared to FSW.

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