Tool Geometry of Friction Stir Welding

Pin Tool Geometry Effects in Friction Stir Welding
J.A. Querin, H.A. Rubisoff, J.A. Schneider
Department of Mechanical Engineering
Mississippi State University
Abstract
In friction stir welding (FSW) there is significant evidence that material can take one of
two different flow paths when being displaced from its original position in front of the
pin tool to its final position in the wake of the weld. The geometry of the pin tool, along
with the process parameters, plays an important role in dictating the path that the material
takes. Each flow path will impart a different thermomechanical history on the material,
consequently altering the material microstructure and subsequent weld properties. The
intention of this research is to isolate the effect that different pin tool attributes have on
the flow paths imparted on the FSWed material. Based on published weld tool
geometries, a variety of weld tools were fabricated and used to join AA2219. Results
from the tensile properties and microstructural characterization will be presented.

Pin Tool Geometry Effects in
Friction Stir Welding
J.A. Querin
H.A. Rubisoff

J.A. Schneider

Mechanical Engineering
Bagley College of Engineering

Mississippi State University

Motivation
Process Variables

Pin Tool

Weld
Schedule

Process
Parameters

Modify

Experiments
Analysis

Fails
Allowables

Passes
Allowables

Minimize testing & increase productivity.

Problem Statement
Determine how pin tool attributes
affect material flow.

threads

0°

15°, 30°, 45°, & 60°

Other features: flats

Transverse Macrographs of
AA2219 FSWs
AS

RS
0 deg, threaded
0.25 in

200 rpm, 4.5 ipm, 7000 lbf
0 deg, no threads
200 rpm, 1.8 ipm, 4000 lbf

0.25 in

60 deg taper
0.25 in

400 rpm, 7.1 ipm, 5500 lbf

Ds

shoulder

LP

pin

Reported Weld Tool
Designs Vary with
Material Joined

Dp

Weld Tool
Geometry

Al

Ti

Steel
(HMTM)

Ds/Dp

2.4...