Abstract
The influence of cold working on the damping capacity and the mechanical properties was investigated for Al–Fe alloys containing 0.2 to 6%Fe. The logarithmic decrement δ and the rigidity modulus G were measured by an inverted torsion pendulum method, and the tensile strength σt by an Instron-type machine.
In the states of furnace cooling and water quenching, the δ was a fairly low value of 3–6×10−3, increased gradually with Fe concentration of up to 2% and then became nearly constant.
By cold working after the heat treatment, the δ became considerably higher with increasing reduction in area RA, and that of the alloys cold-worked by 95% RA was a large value of about 40×10−3. The δ of the alloys cold-worked after furnace cooling was higher than that after water quenching. The increment in δ by cold working is considered to be due to a remarkable increase in density of dislocations and a favorable effect as pinning of a proper amount of the compound Al3Fe (θ phase) against the motion of dislocation lines.
The G in the heat-treated alloys increased gradually with Fe concentration of up to 6%, while the σt increased with Fe concentration of up to 4% and then decreased gradually. By subsequent cold working, the G decreased and σt increased.
