Embraer, a Brazilian aircraft manufacturer, joined the list of WSU/NIAR sponsors last week, said Dwight Burford, WSU CFSP site director and director of NIAR's Advanced Joining Lab. The other sponsors, who contribute at least $150,000 in yearly membership fees, are Bombardier/Learjet, Cessna, the Federal Aviation Administration, General Motors, Hawker Beechcraft and Spirit Aerosystems.
As a multi-institutional Industry/University Cooperative Research Center (I/UCRC), the CFSP brings together the premier friction stir processing academic institutions in the United States and focuses on addressing the needs of aerospace, aeronautic, energy, military and commercial industries in developing friction stir processing.
The other CFSP research sites are lead institution South Dakota School of Mines & Technology, the University of South Carolina, Brigham Young University and the University of Missouri-Rolla.
WSU is the newest university to the center, and will take its turn to host the CFSP spring meeting on April 21-25.
CFSP projects
The five academic institutions bring together highly specialized equipment in a laboratory environment to perform research and development projects in friction stir welding and friction stir processing. These multidisciplinary projects not only involve many engineering programs, but also include other major academic institutions, industrial partners and government laboratories.
The Advanced Joining Lab has been working on three of the 21 CFSP projects and is about to begin two more. One is a proprietary project with General Motors. The other will be led by graduate research assistant Pedro Britos, who will take the lead on the new, still-unnamed project. Britos will travel with Burford to Brazil this week to present the project proposal to Embraer.
“The project will involve weld-quality analysis using software developed at the South Dakota School of Mines and Technology,” Britos said. “It’s a nondestructive test that was developed to use with butt-weld joints, and we’ll try to extend that analysis to lap welds and if possible, to spot welds as well.” This unique software was developed under the auspices of the CFSP.
Britos will be working with Enkhsaikhan Boldsaikhan, the PhD candidate from SDSMT who developed the weld-quality analysis software. Boldsaikhan will join the Advanced Joining Lab as a new hire in November to continue his advanced research.
“When a friction-stir machine is operating, he can measure the force,” Burford explained. “Then he takes that and analyzes it in a computer program, and can determine if the weld is good or bad.
"That’s a phenomenal advantage in this process, because then you can get real-time feedback,” he said. “The operator can be looking at a weld and know if there's a defect in it.”
The other three CFSP projects at NIAR are summarized as follows:
- Performance of Discontinuous Friction Stir Welding
Spearheaded by GRA Josh Merry, this project is investigating the effect of the alignment of a crack with a discontinuous friction stir weld on the growth rate of that crack through a stiffened panel. Panels with discontinuous welds were prepared that were identical to previously investigated friction stir lap welded and riveted panels. The stiffened panels were statically tested in diagonal tension. The results are compared directly to riveted and continuous friction stir lap welded panels.
- Faying Surface Treatments of Friction Stir Spot Welding
The purpose of this project by GRA Jeremy Brown is to investigate the effect of engineered materials, such as chemical conversion coatings, aluminum cladding or anodizing, placed on the faying surface to prevent or reduce corrosion of friction stir spot welds and the adjoining structure. The paper will present the results of this study on the use of interfacial/faying surface materials and the effectiveness of processing parameters developed for a new pin tool design and swept spot pattern. Effectiveness of the process was measured by the degree to which the interfacial/faying surface material is dispersed without producing detrimental effects on the mechanical integrity of the weld.
- Low Z Force Friction Stir Spot Welding
The objective of this project by GRA T.J. Lam is to develop methods for improving cycle time and reducing required Z-forces (vertical forces) in friction stir spot welding (FSSW) without sacrificing joint strength, and then to determine the mechanical properties of such “low” Z-force FSSW. The purpose of this research is to eventually implement the new FSSW methods on an articulated robot at WSU.
