Abstract
In order to clarify the origin of internal stress in solution-hardened alloys being deformed at high temperatures, the dislocation density and structure were determined by TEM observation using Al-Mg alloys with 3 , 4 and 5 at%Mg crept well into the steady state, the internal stress in which had been evaluated by the stress change test. The creep test was carried out at temperatures from 573 to 723 K and at stresses from 4.4 to 70 MPa.
It is found that many attractive junctions are formed by dislocations on different slip planes and a relation
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oindentholds between the internal stress, \barσi, and dislocation density, ρ. Here, M is the Taylor factor, G the shear modulus, and b the magnitude of the Burgers vector. From these findings, it is concluded that the main origin of internal stress is the athermal stress needed for breaking the attractive junctions.
