UNT's Center for Friction Stir Processing (CFSP) is a graduated National Science Foundation (NSF) Industry-University Cooperative Research Center (IUCRC). Founded in 2004, researchers in the Center conduct sponsored research with the guidance of government and industry partners to advance the science and technology of Friction Stir Processing (FSP) and to facilitate efficient technology transfer. Since its formation in 2004, the Center has become internationally recognized as a center of excellence for friction stir welding (FSW) and friction stir processing (FSP) and their many variants. Select Research Updates for recent CFSP publications and presentations.
To advance the state-of-the-art of friction stir welding and processing (FSW&P) and facilitate accelerated industrial application of this technology by:
Planning and carrying out research and development based sound scientific and engineering principles.
Preparing qualified professionals skilled in FSW&P technologies.
Promoting exchange of people, knowledge, and technology among academic, industry and government entities.
Advancing FSW&P to equip stake holders with competitive technologies in the world economy.
Synthesizing and disseminating knowledge about process fundamentals.
Friction stir welding and processing and their variants have many potential aerospace applications. Research in rivet replacement, repair of aging aircraft, fabricated structures, and tooling for assembled structures is undertaken to support the increased adoption of FSW&P by aerospace companies.
Friction stir spot welding shows promise as a joining technology for aluminum sheets used in automotive applications to reduce weight and increase fuel economy. Work at the center is aimed at improving the speed of the process while reducing forces and maintaining high material properties. Novel tool designs and welding parameters are being developed.
As an outcome of conducting numerous projects, researchers are able to draw on a database of process data and corresponding joint properties. This database holds potential for preparing pWPS documents for initial process development trials.
FSW&P Tool Design and Evaluation
Center research in designing and evaluating novel FSW tools has led to reduced process forces, improved process stability, and increased performance in FSW&P in a range of materials from aluminum alloys to HEA alloys. Work continues to identify optimal tools for specific applications.
High Melting Temperatures Materials
Special challenges are found in FSW of materials with melting points above 1000 C. Center research has focused on methods for successfully welding and processing high entropy alloys, stainless steels, high-strength-low-alloy steels, titanium, nickel-based superalloys, and copper.
Manufacturing Tools & Fixtures
Design for manufacturability (DFM) for FSW&P necessarily involves tooling and fixtures required to hold workpieces during these processes. For successful and consistent outcomes, thermal management and process forces is taken into account when designing these essential components in each manufacturing process.
The material microstructure is improved by friction stir processing. Studies in improving microstructure include investigations of fatigue life improvement, in-situ MMC composite manufacturing, repair of casting defects, and the development of strain-active materials.
Process Control and Inspection
In-process control and monitoring techniques, as well as post-process non-destructive analysis techniques are being developed and evaluated for their capabilities to detect process defects. Probability of detection charts have been developed, and in-process techniques have been demonstrated to be as effective as post-weld NDE in detecting volumetric defects.
Increasing the fundamental understanding of the friction stir process is vital to improving the process. Experimental and analytical studies aimed at better understanding the physics of the process and predicting process operation, as well as improving the range of acceptable process parameters, are carried out in the center.
The CFSP is active in providing research opportunities for graduate students, undergraduate students, and secondary school teachers.
In addition, Site personnel offer short courses in FSW&P and related technologies at the university, at professional conferences, and/or in other venues such as corporate sites as requested. Use the contact information links to learn more or to request training and education services.
Facilities and Laboratory
Center facilities include a wide range of friction stir processing equipment. Plunge spot welding, swept spot welding, refill spot welding, linear welding, and robotic welding equipment are available.
In addition to processing equipment, testing and support equipment are integral to Center research. High-speed video, data acquisition, and in-process monitoring equipment are used to track the process during operation. Metallographic equipment, low- and high-speed materials testing systems, dynamic test systems, and fatigue testers are used to evaluate the properties of the processed materials. High-resolution transmission and scanning electron microscopes are used to understand the microstructural characteristics of the resulting welds.