DISLOCATION RELAXATION PEAKS IN HIGH PURITY TUNGSTEN SINGLE CRYSTALS

Experimental observations on the dislocation internal friction spectrum of high purity tungsten single crystals are reported for the temperature range 15K-800K by low frequency torsion pendulum technique. The observed relaxation effects are classified as (α',α), β and γ relaxations, by comparison with the similar dislocation damping spectrum of Mo. Relaxation effects occur at ∼1 Hz in the following temperature ranges : (α',α), 46K-170K ; β, 250K-450K ; γ, 680 K. The γ peak disappears quickly after heating to 800 K. The results are compared with earlier observations of other authors