167 results about "Electron backscatter diffraction" patented technology

The present invention provides an ultra-high strength steel sheet having excellent hydrogen embrittlement resistance, which includes: 0.06 to 0.6% of C; 0.5 to 3% of Si+Al; 0.5 to 3% of Mn; 0.15% or lower of P; and 0.02% or lower of S in terms of mass percentage, and also includes 3% or higher of residual austenite structure, 30% or higher of bainitic ferrite structure, and preferably 50% or lower of polygonal ferrite in terms of an areal ratio to the entire structure, wherein a mean grain size of bainite blocks is smaller than 20 μm as determined by comparing observations of the same region of the bainitic ferrite structure by EBSP (electron back scatter diffraction pattern) and SEM.

The TFT has a channel-forming region formed of a crystalline semiconductor film obtained by heat-treating and crystallizing an amorphous semiconductor film containing silicon as a main component and germanium in an amount of not smaller than 0.1 atomic % but not larger than 10 atomic % while adding a metal element thereto, wherein not smaller than 20% of the lattice plane {101} has an angle of not larger than 10 degrees with respect to the surface of the semiconductor film, not larger than 3% of the lattice plane {001} has an angle of not larger than 10 degrees with respect to the surface of the semiconductor film, and not larger than 5% of the lattice plane {111} has an angle of not larger than 10 degrees with respect to the surface of the semiconductor film as detected by the electron backscatter diffraction pattern method.

The invention provides a method used for determining Bravais lattice of unknown crystal by electron backscatter diffraction. The invention is characterized in that the method comprises the steps as follows: 1) an electron backscatter diffraction spectrum is obtained and the crystal diffraction information in the diffraction spectrum is measured; 2) a two-dimensional reciprocal surface of the crystal is obtained; 3) a three-dimensional reciprocal primitive cell is reconstructed by the two-dimensional reciprocal surface; 4) the cell parameter of the three-dimensional reciprocal primitive cell s worked out according to the width of the Kikuchi band and the angle between the Kikuchi bands in the same Kikuchi electrode; 5) a reciprocal reduced cell of the crystal is solved; 6) the Bravais lattice of the crystal is determined in the reciprocal space; 7) the Bravais lattice of the crystal is determined. In the method, only a scanning electron microscope and an electron backscatter diffraction accessory are used to realize the analysis on unknown lattice of bulk crystals, and the exponential of the Kikuchi band and the Kikuchi electrode in the electron backscatter diffraction spectrum is marked at the same time. The method has no special requirement on the samples to be analyzed, is suitable for quickly analyzing bulk samples, and can be used for analyzing the microstructure morphologies and crystal structure in the buck samples.

To provide a high-strength cold rolled steel sheet that has well-balanced tensile strength and elongation as well as well-balanced tensile strength and stretch-flangeability, and a plated steel sheet manufactured by plating the steel sheet. The high-strength cold rolled steel sheet contains: 0.10 to 0.28% of C, 1.0 to 2.0% of Si, 1.0 to 3.0% of Mn, and 0.03 to 0.10% of Nb in terms of % by mass, wherein the content of Al is controlled to 0.5 or less, the content of P is controlled to 0.15% or less, and the content of S is controlled to 0.02% or less, and wherein residual austenite accounts for 5 to 20%, bainitic ferrite accounts for 50% or more, and polygonal ferrite accounts for 30% or less (containing 0%), of the entire structure, and wherein a mean number of residual austenite blocks is 20 or more as determined when the random area (15 μm×15 μμm) is observed by EBSP (electron back scatter diffraction pattern).

The invention relates to a quantitative measurement method for acicular ferrite of pipeline steel, which utilizes an electron backscattered diffraction (EBSD) assembled on a scanning electron microscope (SEM) to carry out quantitative measurement on the acicular ferrite of the pipeline steel and comprises the following steps: grinding the cross section of a pipeline steel sample into a metallographical polished surface; etching the polished surface with natal, eliminating surface stress and showing an acicular texture; utilizing a conductive adhesive to fix the prepared sample on an EBSD sample stage; controlling the sample stage to rotate for 70 degrees by utilizing the SEM; vacuumizing an electron microscope sample chamber; when the vacuum degree reaches the electron microscope operating requirements, applying operational high pressure to acquiring an image, and finding a typical viewing field; stretching the probe of the EBSD into the sample chamber, and acquiring EBSD pattern data; and carrying out statistical treatment on the EBSD pattern data to obtain the effective crystallite dimension of the acicular ferrite texture. The invention is applied to the quantitative measurement of the acicular ferrite texture with unsharp boundaries in the pipeline steel.

The invention relates to a method for discriminating bainite in a hot rolled TRIP steel and calculating a three phase ratio of the hot rolled TRIP steel. According to the method, an electron backscatter diffraction (EBSD) apparatus arranged on a scanning electron microscope is utilized to carry out quantitative measurement on FCC phase ( residual austenite) and BCC phase (ferrite+ bainite) of a hot rolled TRIP steel; processing is carried out on EBSD pattern data; a bainite structure is distinguished from the BCC phase by utilizing addition of a low angle grain boundary; Image Tool software is utilized to carry out statistics and calculation on three phase structure phase distinguishment graph of the hot rolled TRIP steel so as to obtain a content of a ferrite; and finally, a ration of the residual austenite to the ferrite to the bainite in the hot rolled TRIP steel is determined. Beneficial effects of the method is as follows: calibration on a phase structure can be carried out accurately and it is convenient to calculate all phase structures; and orientation information obtained by an EBSD technology can be utilized to carry out processing on various data according to own researches; therefore, researchers can accurately calibrate all phase structures in controlled rolling and controlled cooling steel with multi-phase structures without increased extra work.

The invention discloses a dual-phase stainless steel crystalline grain structure display method which comprises four working procedures of mechanical polishing, electrolytic polishing, scanning crystal orientation measurement with an electron back-scattering diffraction (EBSD) instrument and crystalline grain structure display. The method comprises the following steps of: processing a test piece; performing mechanical polishing and electrolytic polishing on the test piece; then performing surface scanning crystal orientation measurement on a selected region on the test sample; performing phase discrimination on ferrite phase and austenite phase; and finally performing computer data analysis on crystal orientation data acquired by EBSD, and displaying different orientations with different colors. According to the method, ferrite and austenite dual-phase crystalline grains can be clearly displayed.

The invention provides a SEM transmission electron Kikuchi diffraction apparatus and an analytical method. The apparatus comprises the following components: an electron beam irradiation unit for irradiating electron beams on a sample; an electron backscatter diffraction detector and a sample stage which are located below the electron beam irradiation unit; wherein the sample stage is configured, so that an inclination angle is formed between the sample which is carried on the sample stage and a horizontal plane; and the detector is provided with a phosphor screen which is configured for acquisition and reception of transmission electron signals which are emitted by the sample. Clear transmission electron Kikuchi diffraction patterns are obtained, in order to realize phase identification and phase proportion calculation of crystal grains of nanometer scale, analysis of nanometer scale texture and misorientation, analysis of crystal grain size and shape, analysis of crystal boundary as well as properties of sub-grain and twin crystal, etc.

The invention discloses a convenient method for directionally cutting any crystal face of crystal, belonging to the technical field of crystal material cutting processing. The method is implemented by cutting out a plane arbitrarily to be as the reference plane, then determining longitudinal, transverse and normal indexes of the reference plane by using electron backscattered diffraction (EBSD) technology, then calculating the needed included angle between the reference plane and any crystal face, and finally regulating the crystal cutting direction to obtain the crystal face satisfying requirements by once cutting processing. With the EBSD technology adopted, the EBSD instrument and the traditional crystal material cutting device are combined, thus the crystal of any crystal system can be cut out any crystal face in directional way, namely, the needed crystal face is a high index diffraction face or an extinction face, the invention is especially suitable to the crystal with unknown reference plane orientation and larger crystal orientation deviation, and the bearing accuracy is high, the operation is simple and convenient and the crystal consumption is reduced.

The invention provides a method for preparation of a double-phase zirconium alloy EBSD sample by electrolytic polishing. The method adopts the steps of: firstly, utilizing wire-cutting equipment to cut a workpiece according to certain size from a double-phase zirconium alloy material along the directions of length, width and thickness; subjecting the cut workpiece to step-by-step polishing with abrasive paper to remove the oxide skin and polishing the workpiece bright; taking the double-phase zirconium alloy workpiece as the anode to connect a power supply positive electrode; taking a stainless steel sheet or other steel as the cathode to connect a power supply negative electrode, and preparing a sample by electrolytic polishing technology. The preparation method provided by the invention can achieve high diffraction pattern quality in EBSD (electron backscatter diffraction) testing so as to realize reliable characterization of alpha and beta zirconium alloy dual phase microstructure, grain size, microtexture, grain boundary characteristics, misorientation distribution and the like of the two phase of alpha and beta zirconium alloy. The electrolytic polishing liquid provided by the invention has the advantages of wide raw material sources, simple preparation, and low cost, etc. The electrolytic polishing method involved in the invention has the characteristics of simple operation and stable polishing effect, and the polished workpiece has high good flatness and high surface smoothness.

The invention discloses a test method of crystal orientation matching relationship of nanometer zirconic acid lanthanum epitaxial layer and Ni-W substrate, belonging to the technical field of superconducting thin film performance tests. The test method is characterized in that secondary electronic amplification factor is adjusted and stepping distance is scanned in a system of thermal field emission scanning electron microscope SEM-electron backscattered diffractometer (EBSD), so that 5nA incidence election current can realize that the zirconic acid lanthanum epitaxial layer and Ni-W substrate texture are simultaneously displayed in one polar diagram under the condition that the lowest accelerating voltage is 6kV; one Kikuchi pattern comprises a zirconic acid lanthanum epitaxial layer and Ni-W substrate double phases; on the basis, commercial EBSD analysis software is adopted to measure the crystal orientation matching relationship of the zirconic acid lanthanum epitaxial layer and the Ni-W substrate in the growth directions of in-plane and epitaxial (c-axis). The method is visual and simple, does not need to perform surface pretreatment on the zirconic acid lanthanum and is suitable for other epitaxial material systems.

The invention discloses a preparation method of an electron backscatter diffraction sample with an alloy strip thickness section. The preparation method comprises the following steps: clamping an extremely-thin metal strip obtained by quenching and melt-spinning between two rectangular conductive metal blocks with hardness being approximate to the hardness of a strip alloy in order to fix the two rectangular conductive metal blocks and the thin strip together; vertically placing an alloy thin strip which is already parallel to the conductive metal blocks in a hot mounting press with a thickness section facing downwards horizontally; then, mounting a sample in conductive mounting powder by a hot mounting method, performing coarse grinding on metallographic abrasive paper, and integrally mounting into a cylinder with a certain diameter and a certain height by the hot mounting method; and then, removing a surface stress layer by performing mechanical grinding polishing and vibration polishing to prepare the electron backscatter diffraction sample which has superior surface quality and is provided with a thin strip with a thickness section of dozens of micrometers. The prepared sample has the characteristics of high conductive performance and high calibration rate in electron backscatter diffraction.

A high-strength steel sheet according to the present invention satisfies a predetermined chemical composition, wherein the metal structure of the steel sheet is composed of a polygonal ferrite, a bainite formed in a high temperature range, a bainite formed in a low temperature range and a retained austenite each having a predetermined area ratio, and the distribution of specific crystal grains as determined by an electron backscatter diffraction method employing an average IQ value for each of the crystal grains satisfies formulae (1) and (2) shown below. According to the present invention, it becomes possible to provide a high-strength steel sheet that can exhibit excellent processability and low-temperature toughness even at tensile strength of 590 MPa or more. (1) (IQave-IQmin)/(IQmax-IQmin) >= 0.40; (2) [sigma]IQ/(IQmax-IQmin) <= 0.25

The invention relates to an analysis and detection method of a two-phase proportion in an as-cast structure of a duplex stainless steel, and belongs to the field of the analysis of metal materials. The analysis and detection method is particularly applied to the accurate measurement of contents of ferrite and austenite phases in the as-cast structure of the duplex stainless steel. According to theanalysis and detection method, the electrolytic polishing is carried out for 20s to 30s in a perchloric acid alcohol solution with a volume fraction of 10 to 20 percent to remove a stress layer, wherein a voltage is 10V to 20V and an electric current is 1A to 2A. The two-phase distribution of a well prepared to-be-detected-and-analyzed product is determined according to a special kikuchi patternof each phase, which is possessed by an EBSD (Electron Backscattered Diffraction) analysis system; the determination is not limited to artificial corrosion dyeing, which is difficultly mastered, any more; the difficult differentiation resulted as a contrast between the phases is not obvious enough, which is caused due to a difference of a corrosion effect, is avoided; the quantitative analysis iscarried out on the content of each phase, and the accuracy is higher.

The invention discloses an analysis method for measuring a large-grained silicon steel texture. The analysis method comprises the following steps: I, preparing a to-be-tested electron backscatter diffraction sample from a silicon steel plate; II, cutting a to-be-tested area of the to-be-tested electron backscatter diffraction sample, and distinguishing each crystalline grain in the to-be-tested area according to a crystal boundary; III, calculating the area Am of each crystalline grain and the total area A of the total to-be-tested areas of the sample; IV, carrying out no-texturing treatment, and calculating a ratio A0 of each crystalline grain in the to-be-tested area; V, testing an orientation (hkl) of each crystalline grain in an electron backscatter diffraction way and acquiring an absolute value; VI, dividing Am by A and then by A0 to obtain a relative pole density P(hkl); and VII, marking the relative pole density P(HKL) on a position on a corresponding crystal face in an inverse pole figure. The analysis method has the characteristic that a correct corresponding relationship between a test result and the performance of a material can be established and can be widely applied to the field of the testing of large-grained materials.

A copper alloy sheet material, having an R value of 1 or greater, which is defined by:

R=([BR]+[RDW]+[W])/([C]+[S]+[B])

wherein [BR], [RDW], [W], [C], [S], and [B] represent an area ratio of crystal texture orientation component of BR orientation {3 6 2}<8 5 3>, RD-rotated-cube orientation {0 1 2}<1 0 0>, cube orientation {1 0 0}<0 0 1>, copper orientation {1 2 1}<1 1 1>, S-orientation {2 3 1}<3 4 6>, and brass orientation {1 1 0}<1 1 2>, respectively, in crystal orientation analysis in an EBSD (electron back scatter diffraction) analysis, and having a proof stress of 500 MPa or greater, and an electrical conductivity of 30%IACS or higher; and a production method of the same.

The invention provides a creep fatigue life prediction method based on a crystal plasticity theory. The method comprises the following steps: establishing a representative unit model of ABAQUS based on an electron back scattering diffraction technology; correcting the back stress model and writing the back stress model into a subprogram UMAT to obtain a creep fatigue hysteresis loop; fitting a creep fatigue hysteresis loop through a test parameter method to obtain material parameters; calculating a stress-strain value of each integral point and averaging the stress-strain values to obtain a creep fatigue hysteresis loop and a post-processing cloud atlas; extracting maximum plastic slippage and energy dissipation from the creep fatigue hysteresis loop and the post-processing cloud atlas, analyzing the change rule of the maximum plastic slippage and energy dissipation along with circulation cycles, and providing creep and fatigue indication factors; and predicting the creep fatigue crackinitiation life according to the indication factor. According to the creep fatigue life prediction method, plastic slippage and energy dissipation are used as fatigue and creep indication factors, the creep fatigue damage evolution rule can be better reflected, the crack initiation position can be accurately predicted, and the method has the advantages of being visual, high in applicability and high in accuracy.

The invention relates to a method for quantitatively evaluating each phase structure in hot rolling TRIP (transformation-induced plasticity) steel. The method comprises the following steps: quantitatively measuring an FCC phase (retained austenite) and a BCC phase (ferrite, bainite and martensite) of the hot rolling TRIP steel by using an electronic backscattered diffraction device arranged on a scanning electron microscope; firstly recognizing the retained austenite according to a distinct difference of the FCC phase and the BCC phase in structure, and then quantitatively distinguishing the three phases by using a gray value difference in a kikuchi band contrast BC (Band Contrast) image in EBSD (electron backscattered diffraction) processing software according to the difference of the three similar structure phases of the ferrite, the bainite and the martensite in kikuchi pattern quality, so as to achieve multi-phase separation and quantitative analysis of the hot rolling TRIP steel. The method is accurate and reliable, and can be applied to the technical field of measurement of tissues in the steel.