Internal Friction of Titanium Cold Worked and Annealed

Abstract

The transversal resonance vibration was given in a specimen by electo-magnetic force, and the internal friction was calculated from the half breadth of a resonance curve or the free decay time of a resonance vibration. The effect of annealing on cold rolled or cold tensile deformed titanium, changes in the internal friction of titanium cold rolled or cold tensile-deformed, the strain amplitude dependence of the internal friction by annealing from room temperature to 700°C after cold rollig or cold tensile deforming, and the changes in mechanical properties were measured in order to know the behaviour of lattice defects. The experimental results are as follows:
(1) Titanium cold worked and annealed after cold working has the strain amplitude dependent internal friction.
(2) The internal friction of cold worked titanium increases sharply in the range of a low working degree and has a maximum value, but it does not increase steeply in a high working degree.
(3) The internal friction of specimens annealed after cold working decreases sharply after annealing at 11∼400°C owing to the annihilation of lattice defects and has a constant value after annealing at 400∼500°C, and then decreases at 500∼700°C owing to the recrystallization.