HIGH TEMPERATURE RELAXATION MECHANISMS IN Cu-Al SOLID SOLUTIONS

Abstract

The high temperature damping of copper-a1 umini um sol id solutions has been investigated in single crystals containing various aluminium contents: 3.1-5.4-7.3-9.3 and 11. j 4 a t % of Al. Measurements have been performed in a wide frequency range (10 Hz-10 Hz) between room temperature and 1200 K.

Viscoelastic behavior of a novel aluminum metal matrix composite and comparison with pure aluminum, aluminum alloys, and a composite made of Al–Mg–Si alloy reinforced with SiC particles

“…The peak attributed to GBS, which has been observed in Al-Mg [15], Al-Zn-Mg and Al-Cu-Mg alloys [17,18], is clearly evident in our results for pure aluminum at ≈523 K (250ºC), as shown in Fig. 4.…”

Study on Mechanical Relaxations of 7075 (Al–Zn–Mg) and 2024 (Al–Cu–Mg) Alloys by Application of the Time-Temperature Superposition Principle

“…This background is linked to thermally activated viscous deformation, mainly associated with diffusion-controlled dislocation motion. A relaxation probably contributing to this growth of is the internal friction peak typically exhibited by polycrystalline aluminum centered at ≈300 ∘ C. This peak is traditionally associated with grain boundary sliding (GBS) [1,15,16] and has been observed also in Al-Mg, Al-Zn-Mg, and Al-Cu-Mg alloys [12,13]. For AA 2024-T3 and 2024, a relaxation peak associated with phase [10] is also probably contributing to the monotonical growth of .…”

“…Moreover, Al-Zn-Mg and Al-Cu-Mg alloys and pure aluminum may exhibit relaxations associated with dislocations and grain boundaries [12,13]. Namely, dislocation motion explains some internal friction peaks associated with semicoherent precipitates [14] and the Bordoni peak, which has been extensively studied in cold-worked pure aluminum [1].…”

Onset Frequency of Fatigue Effects in Pure Aluminum and 7075 (AlZnMg) and 2024 (AlCuMg) Alloys

“…The peak is larger (both in width and height) as the loading frequency decreases. Previous works suggest that AlZnMg alloys, AlCuMg alloys and pure Al exhibit mechanical relaxation peaks associated with dislocations and grain boundaries [32,33]. For example, dislocation motions explain some internal friction peaks associated with semi-coherent precipitates for the alloys [34] and also the Bordoni peak, which has been extensively studied in cold-worked pure Al [7].…”