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The present invention relates, in part, to systems for characterizing force (e.g., friction, wear, and/or torque). In one embodiment, the system allows for wear testing of samples in a high throughput manner. In another embodiment, the system allows for torque sensing in a non-contact manner.
The present disclosure relates to a reduced friction torsion component system that makes use of a first frame portion adapted to be coupled to, or integrally formed with, a first object, and forming a first bore, and a second frame portion adapted to be coupled to, or integrally formed with, a second object, and forming a second bore. The two bores are axially aligned and receive at least one elongated hinge component. The elongated hinge component operates to both couple the first and second frame portions together for pivoting movement relative to one another, and also provides a torsional biasing force to enable pivotal deployment from a first position to a second position of one of the first or second frame portions.
In the autogenous joining process of thin 6061-T6 aluminum plates, micro friction stir welding (μFSW) is employed to explore the limitations of high depth to width ratio (HDWR) welding. In this explorative study, 1.25mm plate is joined in a butt joint fashion, multiple HDWR μFSW tools are developed, and the welding parameters are optimized to create a DWR greater than 0.4. A proposed method of implementing induction preheating to the joint is presented and the subsequent characterization of the welds are discussed. Upon completion of the project, the limitations on HDWR μFSW will be more accurately defined, and the best weld will be characterized to determine some of metallurgical properties. This study further expands the operating window for autogenous welding with solid state processes on thin aluminum plate as well as highlight methods for process improvement for tooling design and pre-heating methods.
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Microstructural and mechanical properties of 2.0-mm-thick 2060 Al-Cu-Li alloy joints obtained at different rotation speeds were assessed in this study. The rotation speeds ranged from 400 to 1300 rpm, with welding speed kept at a constant value of 100 mm/min. With the increase in rotation speed, grain coarsening occurred while the density of precipitation decreased in the stir zone (SZ), and great amounts of the Al{sub 2}CuLi and Al{sub 2}Cu phases were dissolved while only small amounts of the Al{sub 3}Zr and Al{sub 3}Li phases remained. The lowest hardness was found at the interface between the heat-affected zone (HAZ) and thermo-mechanically affected zone (TMAZ); the average hardness value of SZ increased, while the lowest hardness moved in the direction away from the center of joints. The ultimate strength (UTS) of weld first increased rapidly and then slowly decreased as rotation speed increased, with a maximum value of 443 MPa obtained at a rotation speed of 600 rpm, reaching 83.58% of the base metal (BM) strength. Three fracture modes were established to illustrate the growth mechanism of the crack. Analysis of the fracture surface showed that insufficient materials flowed and coarsened secondary phases caused the joint fracture.
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