Journal ArticleDOI
Creep and stress relaxation in alpha-brass at low temperatures
Reads0
Chats0
TLDR
In this paper, the authors studied the creep of vacuum annealed polycrystalline 65/36 alpha-brass at constant stress in the range 77-30°k, close to the yield point, at elongations not exceeding 3%.Abstract:
Creep of vacuum annealed polycrystalline 65/36 alpha-brass was studied at constant stress in the range 77–30°k, close to the yield point, at elongations not exceeding 3%. The tensile strain σ increased logarithmically with time, and the characteristic strain 8cr ≡ de/d log10 t, given by the slope of the creep curves in semi-logarithmic representation, decreased approximately linearly with increasing temperature, from 29 × 10−4 at 77°k to 11 × 10−4 at 300°k. The creep was correlated with logarithmic stress relaxation, and the relation 8Cr = - 8rel/χ was established. where χ ≡ d[sgrave]/d σ in the coefficient of work-hardening, and 8 rel≡ d[sgrave]/d log10 t the slope of the corresponding curve obtained with stress relaxation at constant elongation. Both the creep and the relaxation are ascribed to a process of residual slip propagation in which the migration of edge disclocations impeded by the drag of conservatively moving jogs is rate determining. The driving force on the jog is the component of...read more
Citations
More filters
Journal ArticleDOI
Stress Relaxation and the Plastic Deformation of Solids
F. Guiu,P. L. Pratt +1 more
TL;DR: When a solid is plastically deformed in a hard testing machine and the cross-head is arrested, a continuous decrease of load is observed as mentioned in this paper, which can be used to study mechanisms of plastic deformation in solids.
Journal ArticleDOI
Grain-size strengthening in terms of dislocation density measured by resistivity
T. Narutani,J. Takamura +1 more
TL;DR: In this paper, the effect of grain size on flow stress has been investigated in terms of dislocation density, and it was shown that the flow stress is proportional to the square root of dislocations density, irrespective of grain sizes, deformation temperature and the amount of plastic strain.
Journal ArticleDOI
Creep and stress relaxation studies with polycrystalline magnesium
TL;DR: In this paper, the secondary creep rate of fine-grained polycrystalline magnesium was investigated in the strainrate range 3·3 × 10−1 to 3· 3 × 10 −3 sec−1.
Journal ArticleDOI
The measurement of strain-rate sensitivity in superplastic alloys
J. Hedworth,M. J. Stowell +1 more
TL;DR: In this paper, the stressrelaxation method was used to determine strain-rate sensitivities of superplastic alloys from strain rate change tests, and the results showed that the them-values derived by this method, and by a variant of the strainrate change technique, are significantly lower than those obtained using the conventional strain-rates change tests and this is explained in terms of microstructural factors.
Journal ArticleDOI
Mediation and mechanism
TL;DR: It is shown that both concepts can be illustrated using a single causal diagram and it is also shown that mediation implies mechanism but mechanism need not imply mediation.
References
More filters
Journal ArticleDOI
Mathematical theory of stationary dislocations
TL;DR: In this paper, the mathematical theory of stationary dislocations is studied in the context of physics, and it is shown that dislocation can be solved in polynomial time.
Journal ArticleDOI
LXXVIII. A theory of work-hardening of metals II: Flow without slip-lines, recovery and creep
TL;DR: In this paper, the author's previous theory of work-hardening is extended to account for fine slip, which occurs when the stress Gb/l required to obtain dislocations from a source is less than the stress required to drive them through the obstacles in the lattice without the help of thermal activation.
Journal ArticleDOI
The effect of stacking fault energy on low temperature creep in pure metals
P. R. Thornton,P. B. Hirsch +1 more
TL;DR: In this article, the authors derived the stacking fault energies of various metals and derived relative dislocation widths for various metals based on the theoretical analysis relating dislocations width to stacking fault energy, and suggested tentative values for the stacking faults of Au, Ag, Al, Ni, Pb, Zn, Cd, Co and Pt.
Journal ArticleDOI
Solute hardening of close-packed solid solutions
TL;DR: In this article, the contribution of local order and segregation of solute atoms at extended dislocations to the strength of close-packed solid solutions is investigated quantitatively, and theoretical predictions for the initial yield strength of silver-gold, copper-gold and copper-zinc alloys are in good agreement with the experimental data.