Low temperature creep

Low-temperature creep was first studied by Meissner et al in 1930 [ ]. They found that above the yield stress there is appreciable creep even at liquid-helium temperatures. This result gave impetus to further studies at low temperatures. Characterizing creep in cadmium as athermic at 1.4 to 4.2 K, Glen [ assumed that creep proceeds bv dislocation tunneling through crystalline lattice barriers. Arko and Weertman [ revealed the sensitivity of creep to temperature at 4 K and inferred that it was the common thermally activated creep. Gindin etai assumed combined thermal activation and tunneling mechanisms. At the present time, there is not unanimous opinion on the nature of low-temperature creep. 

Fig. 1. Experimental low-temperature creep strain-vs.-time curves for A1 (a), Ag (b), and Cu (c) single crystals under constant stress and at temperatures Ti

The peculiarities of f.c.c. and h.c.p. metal creep appeared to be explainable in terms of the low-temperature creep theory developed by Natsik et al, [ ], which allows for a quantum fluctuation effect upon crystal lattice barriers surmounted by dislocations moving through the crystal. 

Low-temperature creep, at or below 0.5Tj , is believed to be governed by non-dififusion- controlled mechanisms, whereas high-temperature creep, above 0.5T , is diffusion controlled. Stress, time and temperature, mentioned above, act simultaneously during creep. These three parameters determine the creep rate and may be expressed in terms of strain rate as ... 

Source A. Thompson and B.Odegard, Influence of Microstructure on Low Temperature Creep of Ti-5AI-2.5Sn, Metal/. TransyolA, 1973,p899... 

The synergistic effect of corrosion and stress on the creep behavior of magnesium and diecast Mg alloys named corrosion creep has been investigated. We can conclude that at room temperature marked plasticization and fracture are observed in sodium tetraborate buffer solution even under stresses less than 40% of TYS as compared with common low-temperature creep in air almost... 

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