Deformation texture

The notation hkl)[uvw specifies what is called an ideal orientation. Some metals and alloys have sheet textures so sharp that they can be adequately described by stating the ideal orientation to which the grains of the sheet closely conform. Most sheet textures, however, have so much scatter that they can be approximated symbolically only by the sum of a number of ideal orientations or texture components, and even such a description is inadequate. Thus, the deformation texture of brass sheet (70 Cu-30 Zn) is very near the ideal orientation (110)[Tl2]. But both the deformation and recrystallization textures of low-carbon sheet steel have so much scatter that the grain orientations present can be accurately represented only by a graphical description called a pole figure. 

The deformation texture of brass sheet (Fig. 9-19) is fairly sharp, and it is then of interest to know whether or not it can be approximated by an ideal orientation. To find this orientation we successively lay several standard projections over the pole figure, looking for a match between (111) poles and high-density regions. The solid triangles in Fig. 9-19 show such a match they represent the (111) poles of a single crystal oriented so that its (110) plane is parallel to the sheet and the [Tl2] direction parallel to the rolling direction. Reflection of these poles in the... 

Preferred orientation in wire does not always take the form of a pure fiber texture. For example, the deformation texture of iron wire is usually considered to be a [110] fiber texture, but Leber [9.39] showed that a cylindrical texture was also present. Such a texture may be regarded as a sheet texture, (100) [011 ] for iron, wrapped around the wire axis. Thus at any point on the wire surface, a (100) plane is tangent to the surface and a [011] direction parallel to the wire axis. The presence of a cylindrical component in a fiber texture is disclosed by anomalies in the / sin curve the areas under the peaks ascribed to the fiber-texture component will not be in the ratio to be expected from the multiplicities [9.40]. 

The book concentrates heavily on research conducted at the Massachusetts Institute of Technology from the mid 1980s to the mid 2000s by the author and a group of collaborators. It reports on extensive experimental studies and related computational simulations. In the latter there is much emphasis on development of mechanistic models ranging from unit plastic relaxation events to the evolution of deformation textures in channel die compression flow to large plastic strains. At every level the experimental results are compared in detail with predictions from the models. 

The important process variables that affect the annealing texture are grain boundary mobility and major deformation texture (or degree of cold work), preferred orientation of nuclei of the recrystallized grains, composition, initial grain size, and annealing temperature and time. 

Fracture of wires Fracture of metallic glasses Deformation texture Drawing defects Polycrystalline strengthening Fatigue of micro-wires Fatigue of metallic glasses Bonding wires... 

Texture in a polycrystalline structure can arise in quite varied ways, e.g., deformation texture, casting texture, recrystallization texture, plate texture, or fiber texture. 

Some examples of these processes and effects are offered below under sections that deal with (1) ductility at low tem-peratmes, (2) deformation at elevated temperatures (forming), (3) transformation-assisted plasticity, (4) deformation textures, and (5) deformation microstructures. 

Deformation Textures and Microstructures in Alpha- and Beta-Titanium Alloys... 

Dahoun A, Aboulfaraj M, G Sell C, Molinari A and Canova G R (1995) Plastic behavior and deformation textures of poly(etherether ketone) under uniaxial tension and simple shear, Polym Eng Sd 35 317-330. 

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