Preferential Texture Research Articles

The development of {100} texture in Fe 3% Si electrical sheets

Today, a way to strongly raise the operating flux density in rotating machines is to use (100) cubic textured sheets. The hot rolling texture gradient strongly influences the development of the preferential final texture. This paper presents a process based on a specific heterogeneously strained hot deformation and a subsequent annealing which leads to a final misoriented cubic texture after a normal grain growth.

Influence of the Structural Parameters of Polysilicon Films on the Piezoresistive Properties at High Temperature

AbstractPolycrystalline silicon, used as a transducing material in high temperature Silicon On Insulator piezoresistive pressure sensor, is well known to be strongly dependent on the process parameters. Indeed depending on the deposition, doping and annealing conditions, the structural parameters of polysilicon namely grain size and texture may be very different. We use here a complete model of the piezoresistivity in polysilicon including a significant effect at grain boundaries to study the influence of structural parameters on the resistivities, gauge factors and their thermal drifts between room temperature and 200°C. The model validity has been verified experimentally for two types of polysilicon materials (LPCVD at 620°C and LPCVD at 580°C), subsequently B-doped (from 9×1018 to 9×1019 cm−3) and annealed by Rapid Thermal Annealing at 1100°C/20s and 1100°C/40s respectively. A good agreement between theoretical and experimentally determined resistivities and gauge factors at a variable temperature is observed for the two types of polysilicon materials considering different grain sizes with a <110> dominant texture for LPCVD 620°C series and no preferential texture for LPCVD 580°C series.

Effect of process on the rise of texture in magnetic iron sheets

The authors point out that in spite of poor mechanical properties and low electric resistivity, pure iron sheets are more and more used in electrical engineering because of their high working induction, related to high magnetization to saturation. Preferential texture, such as

Texture improvement in high-permeability nonoriented electrical steel by antimony addition

The mechanism of the significant effect of antimony additions on texture improvement was studied, and the results are as follows. When grain size before cold rolling was small, the antimony addition retarded {111} texture formation in the grain growth stage. When grain size before rolling was large, the {110} component increased in the early stage of recrystallization in the antimony-containing specimens because of the dense formation of deformation bands. Based on these effects of antimony additions on preferential texture formation, high-permeability nonoriented electrical steel has been produced at Kawasaki Steel Corporation.

Processing Effects on Microstructural Charcteristics and Properties of Reactively Ion‐Plated Titanium Nitride Coatings

The effects of key processing parameters on the resulting microstructure and mechanical properties of thin TiN coatings, reactively ion‐plated on polished aluminum and steel substrates, were investigated experimentally. A deposition procedure was established and a processing scheme for reactive ion plating was developed. Optimization of processing conditions was achieved by means of controlling the principal ion‐plating parameters to prevent the growth of species different from TiN, evaporant poisoning, and variations in the coating thickness. Emphasis was placed on identifying the effects of critical independent and dependent processing parameters, such as the rf power density, the deposition rate, and the coating thickness, on the TiN microscopic morphology, crystal structure, surface roughness, microhardness, and deformation behavior arising under static and sliding contact loads. Results from various testing and characterization methods revealed that deposition of hard, strongly adherent, and relatively smooth TiN coatings possessing dense microstructures of fine equiaxed grains with a preferential (200) texture can be accomplished under certain ionplating conditions.

On epitaxial growth of diamond films on (100) silicon substrates

We have investigated characteristics of polycrystalline diamond thin films formed by plasma-enhanced chemical vapor deposition method on silicon substrates using Raman spectroscopy, analytical and high-resolution transmission electron microscopy techniques. Grains with average size 1 μm in diameter were observed in these films. The Raman spectra from these films contain the strongest peak at 1335 cm−1, providing the characteristic signature for sp3 (diamond) bonding. The broad peak centered around 1550 cm−1 is believed to be due to some graphitic bonding. From detailed high-resolution images and microdiffraction, films were characterized to be cubic diamond with a lattice parameter of 3.56 Å. Diamond crystallites with fivefold external morphologies were also observed. The large crystallites in the films exhibited preferential texture in 〈011〉 type orientations. These crystallites were found to be twinned in {111} planes. The large 〈011〉 crystallites exhibited matching in {111} or {200} lattice planes of diamond with {022} planes of silicon. This is in agreement with our previous work on the growth of Ni on MgO, which showed that textured growth can occur by matching a set of lattice planes in the absence of matching of lattice constants.

High speed deposition of high-quality ferrite films from aqueous solution at low temperatures (≤90 °C)

We have plated polycrystalline CoxFe3−xO4 (x=0 and 0.43) films on PET and glass substrates at 80–90 °C in an aqueous solution by new three methods: (1) spraying, (2) spin coating, and (3) thin liquid-film methods. The reaction solution is (1) sprayed, (2) spin coated, and (3) flowed through a gap between the substrate and a glass plate, respectively, making a thin (5–400 μm) coating of the solution on the substrate. Since the solution flows off, the composition of the solution on the substrate does not significantly change during the plating, and the ferrite particles formed in the solution are washed away. This improves the film quality compared to previous methods. We have further improved the film quality by introducing CH3COO− buffer ions into the solution, and also by filtering the solution. By the thin liquid-film method, we have obtained maximum deposition rates of ∼160 and ∼300 Å/min by the spraying and the thin liquid-film methods, respectively. The films of Fe3O4 and CoxFe3–xO4 (x=0.43) plated by the thin liquid-film method exhibited a preferential texture of (100) and (111) planes, respectively, parallel to the surface. Both films had a columnar structure normal to the surface, but the magnetization lies in the surface plane.

「薄液膜法」によるフェライト・メッキ膜の堆積速度と膜質の改善

We have plated polycrystalline CoxFe3-xO4 films by “thin liquid-film” method at T=55-90°C and pH=7.0 using NaNO2 as an oxidizing agent. The film quality was improved by (1) introducing CH3COONH4 buffer which stabilizes the pH, and (2) filtering the reaction solution. Thus we obtained a film deposition rate of 300 Å/min at 90°C for x=0 and 0.43 without deterioration of the film quality. The deposition rate increased with the temperature. The films of Fe3O4 and CoxFe3-xO4 (x=0.43) plated at 90°C on glass substrates exhibited a preferential texture of (100) and (111) planes respectively, parallel to the surface. Both films had a columnar structure normal to the surface plane, but the magnetization lay in the surface plane. Fe3O4 films plated at 90°C on α-Al2O3 (0001) and MgAl2O4 (100) crystal plates exhibited a preferential texture of (111) and (100) planes, respectively, the oxygen-packing layer of the substrate coinciding with that of the ferrite film.

A Study of the Kinetic of Precipitation and the Morphology of Precipitates Induced by Plastic Deformation in Al-Zn Alloys

ABSTRACTThe influence of plastic deformation on the kinetic of precipitation and the morphology of precipitates in an Al-Zn 4.4 % at. studied by T.E.P. and SAXS is reported. Some results can be pointed out ; after a given amount plastic deformation at room temperature by tensile strength:i - the precipitates have a flat shape (instead of the spherical or ellipsoidal shape usualy observed in this alloys.ii - the precipitate volume fraction is a function of strain (ε) and strain rate (ė). For a given ė, the higher precipitate volume fraction is obtained with the higher ε. For a given ε, the lower ė the higher the volume fraction of precipitates.iii - the scattering intensities at small angle for three orientations of the sample (α =0,45°, 90° where α is the angle between the axis of tensile and the scattering vector- are different. A calculation for an anisotropic orientation of flat discs shows that precipitates have a preferential texture. The orientation is about 50° from the tensile axis.

An X-ray diffraction study on the lattice imperfections in vapour-deposited FCC (Ag-4.5 at.% Ge) alloy films

Fourier analyses of both multiple and single-order reflections in FCC (Ag-4.5 at.% Ge) alloy films (68 to 238 nm thick) indicated appreciable coherent domain size and lattice strain effects with slight lattice contraction and significant compressive long-range residual stress. The study further reveals large concentrations of growth twin stacking faults but none that were intrinsic or extrinsic. The films showed a high dislocation density and a strong preferential texture along (111).

Dependence of the deformability of high chromium steel Kh17 on texture

1. The preferential texture of steel affects the value of the plastic anisotropy of steel Kh17 and also its ability to be elongated. The texture of a “cube on an angle” {111} is the most conducive for elongating sheet steel Kh17. 2. With a definite degree of compression on cold rolling, the steels can obtain the necessary crystalline orientation, and, at the same time, the necessary plastic anisotropy. 3. The mechanical properties of steel Kh17 alone cannot characterize its ability to be elongated, since steel with the worse characteristics of plasticity, but with a large anisotropy of plasticity, is most susceptible to elongation. 4. The largest anisotropies of plasticity and the best characteristics on elongating steel Kh17 are found at degrees of deformation of 70%.

Magnetostrictive Effects in Cylindrical Films

The classical expression of the magnetoelastic energy of a monocrystal is transformed according to the most general rotation of the crystalline axes with respect to a given reference system. It is then possible to calculate the effect of a given stress on a polycrystalline material. It is shown that it is only for perfectly random crystallographic orientations that it is possible to cancel the ``macroscopic'' magnetostrictive effects of all the strains at the same composition for a magnetic alloy. If a cylindrical magnetic film with a preferential texture is made insensitive to an axial elongation, it will exhibit a magnetostrictive skew of its magnetic easy axis when the wire is twisted. The microscopic effects of stresses are also investigated in all cases: the so-called ``isotropic stresses'' give a dispersion of the easy axis.