22 results about "Basal plane" patented technology

The invention belongs to the technical field of testing and characterization of semiconductor materials, and particularly relates to a lossless characterization method of semiconductor material-based plane dislocation. Comprising the following steps: preparing a to-be-detected semiconductor material, selecting diffraction geometry according to a BPD (Bourysi vector) of the to-be-detected semiconductor material, and enabling a point product result of the diffraction geometry and the Bourysi vector to be not 0; using an X-ray morphology system to calculate corresponding detection parameters according to diffraction geometry to detect the semiconductor material, and imaging the BPD in the detection range; performing statistical analysis on an imaging result to obtain BPD quantity information in a unit area; or BPD length information in a unit volume is obtained, or a tomography imaging result is obtained. According to the method, non-extinction diffraction geometry is selected for accurate recognition and analysis, nondestructive testing of the silicon carbide material base plane dislocation is achieved, full-coverage imaging can be carried out on a large-size sample, and the destructive problem in a traditional characterization means is avoided.

Inventive techniques for forming unique compositions of matter are disclosed, as well as associated physical characteristics and properties of the materials. In particular, particles comprising a metal lattice are characterized by having carbon (preferably graphene) disposed within the crystalline lattice structure thereof. The carbon is at least partially disposed in interstitial sites of the metal lattice, and may be present in amounts ranging from about 15 wt % to about 90 wt % of the total particle mass, with about 15 wt % to about 60 wt % being disposed in the interstitial sites, e.g., between basal planes, of the metal lattice. The carbon, moreover, is substantially homogeneously dispersed throughout the resultant material, conveying unique and advantageous properties such as strength-to-weight ratio, density, mechanical toughness, sheer strength, flex strength, hardness, anti-corrosiveness, electrical and / or thermal conductivity, etc. as described herein. In some approaches, the graphene is pristine, and has corresponding physical characteristics as described herein.

The present application belongs to the field of light metal plastic forming, and particularly relates to a device and method for preparing fine-grained magnesium alloy rod by asymmetric multi-directional shear extrusion. The wedge block combination in the present application can combine multi-directional shear extrusion deformation and differential speed torsional deformation, effectively weaken the magnesium alloy basal plane texture, and improve the mechanical properties of the magnesium alloy. While the magnesium alloy material is subjected to torsional extrusion in the torsional extrusion deformation zone, the sectional area of the channel gradually decreases, and the angle of the channel deflection is different, so that the frictional force of the magnesium alloy material on the surface of the convex and concave dies at the contact position is different, and the degree of torsional deformation is also different, so that the material realizes differential speed torsional deformation, and the grain refinement effect of the magnesium alloy rod is more remarkable. When the magnesium alloy material passes through the large and small concave dies, the deformation degrees of the magnesium alloy material are different due to the particularity of the structure, so that the grain refinement is effectively realized. At the same time, the flowability of the magnesium alloy material is also different, causing differential speed flow to deflect the c-axis, thereby weakening the texture.

The application discloses a method for improving the impact resistance and explosion resistance of a titanium alloy. The titanium alloy plate has an elongated macrostructure feature, the basal plane pole points of which are uniformly distributed in a plane perpendicular to the impact direction, and the overall {10-10} and {11-20} crystal face pole patterns have a uniform distribution feature. The preparation process comprises the following steps: forging blank selection, forging blank heating and pretreatment, square shaping, spread forming, multi-fire rolling, and solid solution aging heat treatment. According to whether the original forging blank has a specified organizational form, different high-temperature heating, holding and shaping systems are used to control and stabilize the macrostructure, alpha and beta two-phase structure and texture distribution of the plate. The titanium alloy plate prepared by the above process has good organizational stability, texture uniformity and impact damage resistance.

Provided are a method for manufacturing a silicon carbide single crystal, and a silicon carbide single crystal ingot which ensure a high crystal growth rate and increase the ratio of conversion from basal plane dislocations to threading edge dislocations. The method prepares a seed substrate composed of silicon carbide having an off-angle in a [1-100] direction with respect to a {0001} plane; and grows a silicon carbide single crystal layer on the seed substrate by an HTCVD method, thereby converting basal plane dislocations contained in the seed substrate to threading edge dislocations during crystal growth.

Provided are a method for manufacturing a silicon carbide single crystal, which can suppress conversion of threading edge dislocations into prismatic plane dislocations and conversion of the prismatic plane dislocations into basal plane dislocations; and a silicon carbide single crystal ingot and a silicon carbide wafer, in which conversion from threading edge dislocations into prismatic plane dislocations and conversion from the prismatic plane dislocations into basal plane dislocations have been suppressed. A silicon carbide single crystal is grown on the surface of a seed substrate by a gas method so that a temperature gradient in the radial direction of the seed substrate takes a predetermined value or lower during the growth. The area of regions T1 to T4, where regions R1 to R3 of a basal plane whose shear stresses exceed critical resolved shear stress, and regions S1 to S4 of a prismatic plane whose shear stresses exceed critical resolved shear stress overlap, is less than a half of the area of a crystal growth surface. Furthermore, the area of the regions T1 to T4 is smaller than the area of regions V1 to V4 where a region R4 of the basal plane whose shear stress does not exceed the critical resolved shear stress overlaps the regions S1 to S4.

The invention discloses a method for obtaining a basal plane uniaxial texture in a pure zirconium plate through one-way rolling. The method comprises the following steps: sequentially polishing a pure zirconium plate sample to be bright step by step by adopting different numbers of abrasive paper, cleaning and drying; the sample is subjected to vacuum tube sealing treatment and then subjected to a heat treatment process, the temperature is increased to 950-1050 DEG C at the speed of 4-6 DEG C / min and stabilized for 9-11 min, then the sample is placed in the furnace to be subjected to heat preservation for 1-1.2 h, and the sample is taken out to be subjected to air cooling after the heat preservation time is reached; rolling treatment is conducted on the pure zirconium plate sample, the rolling strain rate is 10-20 s <-1 >, the single-pass rolling reduction is 0.1-0.15 mm, the total rolling reduction is 20-50%, and the rolling temperature range is 0-25 DEG C. According to the method, a pure zirconium plate sample is subjected to heating and heat preservation (in a complete beta-phase region) and then is subjected to air cooling treatment, so that a disordered oriented thick lath structure is obtained; and in the rolling deformation process, a large number of {10-12} and {10-22} twin crystals can be generated and act together with dislocation slippage, and the orientation of original crystal grains is remarkably changed, so that a basal plane uniaxial texture which cannot be generated by conventional rolling machining is obtained.

The application discloses a titanium alloy extruded pipe blank with gradient texture and a preparation method thereof. The titanium alloy extruded pipe blank with gradient texture has gradient texture characteristics in the wall thickness direction, including a surface layer region: within a depth range of 0-1.5 μm from an outer surface and / or an inner surface, a {0001} basal plane strong shear texture is formed, and the crystallographic orientation of the region has an included angle of 30°-60° with the radial direction; a core region: a wall thickness center region, the texture strength is weak, and the texture strength is randomly distributed or weak; a transition region: between the surface layer region and the core region, the texture strength changes in a gradient manner; and a maximum pole density difference of the surface layer and the core region is greater than or equal to 4. Through the gradient texture design, the surface layer of the pipe blank forms a strong shear texture, has high crack resistance, the core region keeps random texture, and provides isotropic high plastic deformation capacity. The performance zoning enables the pipe to withstand a larger deformation amount without being prone to cracking in the subsequent cold working process.

The invention discloses an in-plane texture heterogeneous magnesium alloy and a preparation method thereof. The preparation method of the in-plane texture isomeric magnesium alloy comprises the following steps: (1) preparing a basal plane texture magnesium alloy plate; and (2) rolling the base texture magnesium alloy plate in the step (1) by using a roller-shaped rolling die to obtain the base texture magnesium alloy plate with the deformation of 3-8%, a main body of the roller-shaped rolling die is a roller, and a plurality of protrusions (2) which are evenly distributed in an array mode are arranged on the outer surface of a roller body (1) of the roller. According to the method, multi-pass deformation, complex intermediate / subsequent annealing and expensive special equipment are omitted, the process is extremely simple, the cost is extremely low, the huge potential of large-scale and low-cost industrial production is achieved, and the problems that in the prior art, the process is complex, the cost is high and the efficiency is low are solved.

The invention relates to the technical field of laser cladding, in particular to a method and a system for predicting the size of a laser cladding cross section of an inclined base plane. Aiming at the problems of fracture, holes, noise and the like of the cladding layer boundary in a deep learning model prediction result, the invention provides an end point extension repair algorithm based on graph structure analysis, and boundary defects are effectively repaired through the steps of morphological operation, connected domain analysis, path reverse extension and the like. In order to improve the cladding layer section prediction precision, a Pix2Pix model is applied to cladding layer section form prediction for the first time, and perception loss is introduced to enhance the perception ability of the model to boundary details and a global structure. Besides, structural similarity indexes are introduced, molten pool images with high similarity are extracted from molten pool videos under different parameter conditions to serve as an extended training set, and the generalization ability and robustness of the model are effectively improved.

A method of preventing basal plane dislocations (BPDs) from expanding from a SiC substrate or a highly doped buffer layer into an epitaxial device / active layer comprising the steps of providing a substrate, etching the substrate, converting BPDs to electrically benign threading edge dislocations, growing a first buffer layer on the substrate, creating a growth interrupt layer or second etch layer, growing a second buffer layer, growing a drift layer, and preventing BPDs from expanding into the drift layer. A device capable of preventing basal plane dislocations (BPDs) from expanding from a SiC substrate or a highly doped buffer layer into an epitaxial device / active layer comprising a substrate, a first buffer layer, a growth interrupt layer or etch layer, a second buffer layer and a drift layer. The drift layer carrier lifetime is not reduced. BPD expansion is prevented at current densities up to 12 kA / cm2.

To reduce "BPD" in a buffer layer.SOLUTION: When the basal plane dislocation concentration in the buffer layer is equal to or more than 0cm - 2 and less than 5cm - 2, the buffer layer of the product substrate is formed under the same condition as the film formation condition when the buffer layer is formed on the inspection substrate. In the inspection method described above, the wavelengths of the exciting light are equal to or less than 386nm. The integrated illumination of the exciting light is 1. 6W. cm - 2. sec or more. The photoluminescence light is received via a light receiving filter. The light-receiving wavelengths are equal to or longer than the wavelengths of the exciting light and equal to or shorter than the 399nm.SELECTED DRAWING: Figure 4

The present invention provides a SiC substrate capable of reducing cracking and cracking during substrate processing. The SiC substrate is provided with a biaxially oriented SiC layer, and when the entire region of an XRT image obtained by X-ray topography (XRT) measurement of the biaxially oriented SiC layer is divided into a lattice shape in which a region having a longitudinal direction of 4 mm * a transverse direction of 4 mm * a depth of 28 [mu] m is given per lattice, X (cm / cm < 3 >) represents the average volume density of basal plane dislocations (BPD) per lattice, and X (cm / cm < 3 >) represents the average volume density of the basal plane dislocations (BPD) per lattice. There are no continuous 10 cells or more on one vertical and horizontal straight line in a region that reaches 5X (cm / cm < 3 >) or more per cell.

There is provided a SiC substrate including a biaxially oriented SiC layer, wherein, in an XRT image obtained by subjecting the biaxially oriented SiC layer to X-ray topography (XRT) measurement, when the entire XRT image is divided into a lattice pattern giving a region of 4 mm longitudinal length×4 mm lateral length×28 μm depth per square and an average value of a volume density of basal plane dislocations (BPDs) per square is defined as X (cm / cm3), regions having 5X (cm / cm3) or more per square do not extend for 10 or more continuous squares in a straight line in either a longitudinal or lateral direction.

The application discloses a method for regulating magnesium alloy basal precipitates, and belongs to the technical field of magnesium alloys. The method comprises the following steps: melting and casting raw materials according to a preset Mg-Gd-Y-Zn-Mn alloy composition and content, and then performing rapid solidification and artificial aging treatment; the Mg-Gd-Y-Zn-Mn alloy comprises 8.67%-8.89% of Gd, 3.85%-3.95% of Y, 3.28%-6.47% of Zn and 0.96%-1.96% of Mn in terms of mass percentage, and the balance is magnesium and inevitable impurities; and (Gd+Y):Zn=1:1 or 2:1 in terms of atomic percentage. According to the above method, high-density gamma'' basal precipitates are maintained during peak aging and overaging, and the process window for forming high-density distributed gamma'' basal precipitates in the Mg-Gd-Y-Zn-Mn alloy is effectively increased.

The invention discloses a silicon carbide crystal growth device. The silicon carbide crystal growth device comprises a growth container; the powder container is suitable for containing silicon carbide powder, the powder container is arranged in the growth container, and a containing space is formed between the outer circumferential surface of the powder container and the inner circumferential surface of the growth container; the flow guide cylinder comprises a plurality of arc-shaped flow guide parts which can be mutually separated in the circumferential direction, the flow guide cylinder is supported on the upper end face of the powder container, and each arc-shaped flow guide part can move in the radial direction and is constructed to be suitable for sliding to the containing space from the upper end face of the powder container under the pushing of growing polycrystals. According to the silicon carbide crystal growing device, the dislocation defect density of a crystal basal plane can be reduced, an annealing process and growing temperature do not need to be sacrificed, and the silicon carbide crystal growing device has the advantages of small crystal defects, high production efficiency and the like.

Provided is a method capable of simultaneously producing multiple sheets of an SiC single crystal substrate having a small amount of warpage, a low basal plane dislocation density, and a large crystal growth thickness. This method involves: a step for preparing a plurality of containers; a step for arranging, in each of the containers, an SiC single crystal as a seed crystal and SiC powder mixture containing SiC powder and a liquid phase generation aid so as to form an SiC powder mixture layer in which the SiC powder mixture is in contact with at least one plane of the SiC single crystal, wherein the liquid phase generation aid contains an oxide; a step for arranging the containers so as to be aligned with each other in the horizontal direction and / or the vertical direction in a firing furnace; and a step for heating the inside of the firing furnace so as to form a temperature gradient in which the temperature is increased or decreased from an upper portion toward a lower portion to subject the containers containing the seed crystal and the SiC powder mixture to heat treatment at an average furnace temperature of 2240-2560°C, thereby growing the SiC single crystal on the seed crystal.

Silicon carbide epitaxy substrate (100), comprising: a silicon carbide single crystal substrate (10) with a diameter of 100 mm or larger and with a principal surface (10A) inclined at an angle of more than 0 degrees and not more than 8 degrees with respect to a {0001} plane; a silicon carbide epitaxy layer (11) formed on the main surface (10A) and having a thickness of 20 µm or more; a basal plane dislocation (110, 111) contained in the silicon carbide epitaxy layer (11), wherein one end (111a) is connected to a screw dislocation (120) contained in the silicon carbide epitaxy layer (11) and the other end (111b) is present in a surface (11A) of the silicon carbide epitaxy layer (11), and a further basal plane dislocation (112) extending in the <11-20> direction and connected to the other end (111b) of the basal plane dislocation (110, 111), wherein the basal plane dislocation (110, 111) extends in a direction with an inclination of 20 degrees or more and 80 degrees or less with respect to a <11-20> direction in a {0001} basal plane, and where the density of the basal plane dislocation (110, 111) is 0.05 / cm 2 or less.

Provided is a method for manufacturing a silicon carbide substrate 100 that has a substrate layer 101 and an epitaxial layer 102, the method comprising: a detection step for detecting a basal plane dislocation (BPD) present in the epitaxial layer 102 by irradiating the silicon carbide substrate 100 with inspection light L1; an expansion step for irradiating the area in which the basal plane dislocation (BPD) detected in the detection step is present with expansion light L3 for expanding a Shockley type stacking fault (SSF) from the basal plane dislocation (BPD); and a contraction step for irradiating the Shockley type stacking fault (SSF) expanded from the basal plane dislocation (BPD) in the expansion step with contraction light L4 for contracting the Shockley type stacking fault (SSF). In cases where a plurality of basal plane dislocations (BPD) are detected in the detection step, in the expansion step, after irradiating one region in which a basal plane dislocation (BPD) is present with expansion light, another region in which a basal plane dislocation (BPD) is present is irradiated with expansion light L3 concurrently with the contraction step, and this operation is repeated for all regions in which a basal plane dislocation (BPD) is present.

The invention provides a method and a system for predicting influence of basal plane dislocation on material performance, which are applied to the technical field of material science, and the method comprises the following steps: obtaining input characteristics of a to-be-predicted material, the input characteristics of the to-be-predicted material at least comprising basal plane dislocation density, basal plane dislocation type, doping rate, temperature and external field intensity; inputting the input features of the to-be-predicted material into a performance influence prediction model for performance prediction to obtain a performance prediction value of the to-be-predicted material; the performance influence prediction model is obtained by training based on the first data set and the trained machine learning potential model. According to the scheme, the performance influence prediction model is obtained through training of the first data set and the trained machine learning potential model, and then the performance prediction value of the to-be-predicted material is obtained through prediction of the performance influence prediction model. The machine learning potential model covers the association between the long-term evolution of the basal plane dislocation and the performance of the large-size material, so that the prediction effect of the association between the basal plane dislocation and the performance of the material is improved.

The invention relates to a SiC single crystal, a SiC substrate, and a SiC epitaxial wafer. The purpose of the present invention is to provide a SiC single crystal capable of reducing the basal plane dislocation density. In the SiC single crystal according to the present embodiment, lattice planes measured along a first straight line, a second straight line, a third straight line, a fourth straight line, a fifth straight line, and a sixth straight line are each curved in a convex shape, and in the lattice planes measured along the first straight line, the second straight line, the third straight line, the fourth straight line, the fifth straight line, and the sixth straight line, the first straight line, the second straight line, the third straight line, the fourth straight line, the fifth straight line, and the sixth straight line are curved in a convex shape. The first straight line, the second straight line, the third straight line, the fourth straight line, the fifth straight line, and the sixth straight line respectively pass through the center in plan view from the thickness direction and are inclined by 30 degrees one by one with respect to the center.

The invention discloses a method for regulating and controlling a magnesium alloy basal plane precipitated phase, and belongs to the technical field of magnesium alloys. The method comprises the steps that raw materials are smelted and cast according to preset Mg-Gd-Y-Zn-Mn alloy composition and content, and then rapid solidification and artificial aging treatment are conducted; the Mg-Gd-Y-Zn-Mn alloy is prepared from the following components in percentage by mass: 8.67 percent to 8.89 percent of Gd, 3.85 percent to 3.95 percent of Y, 3.28 percent to 6.47 percent of Zn, 0.96 percent to 1.96 percent of Mn and the balance of magnesium and inevitable impurities, and in atomic percent, the ratio of (Gd + Y) to Zn is 1: 1 or 2: 1. According to the method, high-density gamma ''basal plane precipitated phase distribution is kept in the peak aging process and the overaging process, and the process window for forming the high-density distributed gamma'' basal plane precipitated phase in the Mg-Gd-Y-Zn-Mn alloy is effectively enlarged.