Analysis of Internal Friction Peaks in High Purity Molybdenum by a Viscoelastic Procedure Independent of the Relaxation Strength

摘要

In this work we present a novel procedure, involving linear viscoelastic analysis, to discriminate the two possible contributions of the observed damping peak which appears around 840 K - 1050 K in mechanically deformed high purity single-crystalline molybdenum. An interesting feature of the procedure is that, for low damping samples, it can efficiently resolve experimental peaks that result from the superposition of different processes independently of the ratio between their relaxation strengths. This allows us to confirm that two different relaxation processes appear in molybdenum in the temperature range about 0.3 Tm, one around 840 K, and the other one near 1050 K. These can be related to diffusion and to a coupled mechanism involving creation and diffusion of vacancies, respectively.