scholarly journals DEVELOPMENT OF CYCLIC SLIP BANDS IN UFG COPPER IN GIGACYCLE FATIGUE

2013 ◽  
Vol 19 (2) ◽  
Author(s):  
Lucie Navrátilová ◽  
Ludvík Kunz ◽  
František Nový ◽  
Rastislav Mintách
Keyword(s):  
Slip Bands ◽  
Cyclic Slip

Surface Relief Formation in Relation to the Underlying Dislocation Arrangement

2016 ◽  
Vol 258 ◽  
pp. 526-529 ◽  
Author(s):  
Veronika Mazánová ◽  
Milan Heczko ◽  
Ivo Kuběna ◽  
Jaroslav Polák
Keyword(s):  
Electron Microscopy ◽  
Dislocation Structure ◽  
Fatigue Crack Initiation ◽  
Surface Profile ◽  
Specimen Surface ◽  
Slip Bands ◽  
Transmission Electron ◽  
Persistent Slip Bands ◽  
Relief Formation ◽  
Cyclic Slip

Two fatigued materials with f.c.c. lattice, i.e. pure polycrystalline copper and austenitic Sanicro 25 stainless steel, were subjected to the study of the persistent slip markings (PSMs) developed on the surface of the suitably oriented grains. They were observed using scanning electron microscopy (SEM) and thin surface FIB lamellae were prepared and studied by transmission electron microscopy (TEM). The aim was to correlate the specimen surface profile with the underlying internal dislocation structure. The localization of the intensive cyclic slip into persistent slip bands (PSBs) of the material was observed and associated with the PSMs on the specimen surface. Extrusions, intrusions and the dislocation structure appertaining to them were analysed, documented and discussed in relation to the models of fatigue crack initiation.

Extrusion and intrusion by cyclic slip in copper

1957 ◽  
Vol 242 (1229) ◽  
pp. 211-213 ◽  
Keyword(s):  
Fatigue Cycle ◽  
Model Based ◽  
Slip Bands ◽  
Cyclic Slip

Extrusions and intrusions have been observed on slip bands in copper fatigued at 300, 90 and 20°K. A model based on a sequence of slip movements during a fatigue cycle is proposed to explain their formation.

Formation of Persistent Slip Band in Fatigued Copper Single Crystals

1982 ◽  
Vol 40 ◽  
pp. 470-471
Author(s):  
N. Y. Jin
Keyword(s):  
Volume Fraction ◽  
Fatigue Cracks ◽  
Wall Structure ◽  
Matrix Structure ◽  
Dislocation Dipole ◽  
Slip Bands ◽  
Persistent Slip Bands ◽  
The Matrix ◽  
Hard Shell ◽  
Copper Single Crystals

Localised plastic deformation in Persistent Slip Bands(PSBs) is a characteristic feature of fatigue in many materials. The dislocation structure in the PSBs contains regularly spaced dislocation dipole walls occupying a volume fraction of around 10%. The remainder of the specimen, the inactive "matrix", contains dislocation veins at a volume fraction of 50% or more. Walls and veins are both separated by regions in which the dislocation density is lower by some orders of magnitude. Since the PSBs offer favorable sites for the initiation of fatigue cracks, the formation of the PSB wall structure is of great interest. Winter has proposed that PSBs form as the result of a transformation of the matrix structure to a regular wall structure, and that the instability occurs among the broad dipoles near the center of a vein rather than in the hard shell surounding the vein as argued by Kulmann-Wilsdorf.

Fatigue hardening and nucleation of persistent slip bands in copper

1982 ◽  
Vol 30 (3) ◽  
pp. 711-718 ◽  
Author(s):  
O.B Pedersen ◽  
A.T Winter
Keyword(s):  
Slip Bands ◽  
Persistent Slip Bands

scholarly journals The plastic deformation of iron and the formation of Neumann lines

1925 ◽  
Vol 108 (745) ◽  
pp. 231-231
Keyword(s):  
Plastic Deformation ◽  
Pure Iron ◽  
Crystal Surfaces ◽  
Size And Shape ◽  
Slip Bands ◽  
Wide Range ◽  
Moderate Rate ◽  
Rapid Deformation

The object of the investigation described in the present paper was to ascertain the manner in which wide variations in speed affect the mechanism of deformation in plastic metals. Iron was selected as the first metal for experiment, mainly because it is known that rapid deformation produced by shock is accompanied in this metal by special features, known as Neumann lines or lamellæ. When a piece of nearly pure iron, of suitable size and shape, with one face polished and etched, is subsequently subjected to plastic deformation at a moderate rate, the crystal surfaces, when examined under the microscope after deformation, show the well-known appearance of slip bands (1). The present experiments were undertaken in the first instance to ascertain whether the character, number and appearance of such slip bands would be appreciably affected by varying the rate of deformation over a wide range. For the sake of convenience, deformation by compression has been employed, the metal being used in the form of small rectangular prisms, measuring in some instances 0.44 inch by 0.44 inch in section by 0.7 inch in height.

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