Heat Loss Through the Tool in Friction stir welding

Ashley Lavin

Ken Ross

How Friction Stir Welding (FSW)Works

Pin

Downward force maintains pressure

Rotating tool creates friction and applies pressure

Direction of tool translation

Purpose

Determine the effect of tool material on the heat lost during FSW through the tool

Materials

Tools with identical geometries were made from the following materials. Shafts are painted black to create a constant emissivity for the tool surface Tungsten k = 84.02 H-13 Tool Steel k= 28.6 Nickel Alloy (ALGxN) k=11.8

2m

kW

Procedure

Perform a weld using each of the tools at the same traverse and rotational speed and record the following Record temperature of the tool at the top and

bottom of the shaft using ThermaCam Record power input into the weld

Calculate the fraction of the total power lost to heat transfer through the tool using each material

Setup

Tool

ThermaCam

Workpiece

Video of Weld(H-13 Tool)

Analysis

)(/)( 12 ALTTkQtool

T1

T2

L

60

2 MRPMPower

PowerQQQ tooltotalTool //

Nomenclature

•k= thermal conductivity W/mK

•L= Length (m)

•T= temperature (Celsius)

•RPM= rotation per minute

•M=Torque (Nm)

Results

Qloss = 217.17 W 60.62 W 22.87W

Qloss/Qtotal 10.0% 3.24% 0.85%

Where Qloss/Qtotal is percent of the total heat input into the weld lost though the tool

Tungsten H-13 NLGxN

Conclusion

The ratio of heat lost through the tool correlates to the thermal conductivity of the tool material

-30.00

20.00

70.00

120.00

170.00

220.00

k Qloss Qloss/Qtot

Tungsten

H-13

NLGxN

Questions

Analysis Macro