28-05-2014, 04:03 PM
Evaluation of Friction Stir Weld Process and Properties for Aircraft Application
Evaluation of Friction.pdf (Size: 1.3 MB / Downloads: 80)
Purpose
• The key to developing allowables for any material or
process is that the expected variation must be
understood and controllable within certain limits.
• Friction Stir Welding (FSW) is a relatively new thermo-
mechanical processing and joining technique under
investigation for its potential inclusion in the MMPDS or
other similar standard properties data reference.
Sources of Variation for FSW
• Welding Parameters
– Strength varies from Low (<50% Joint Efficiency) up to the
theoretical maximum for a given tool.
• Tool Design
– Affects the theoretical maximum for a given alloy/thickness
combination.
• Site / Facility
– Varies up to theoretical maximum, and is affected by fixturing,
machine type, control system tuning, operator, lab conditions,
etc.
• Base Material
– Joint strengths can be affected by large variations in parent
material strength and material thickness.
Results
• Stable process zones were identified for three
of the tools during the second round DOE
– S-basis values were calculated for each tool
– T99 and T90 values were calculated for pooled data
from the three tools.
• Acceptable parameters were found for the
remaining tools, but were not fully optimized.