13 results about "Interfacial stress" patented technology

The invention discloses a preparation method of a PZT multilayer piezoelectric film based on interface stress regulation and control, and belongs to the technical field of film preparation. Comprising the steps of S1, providing a substrate; s2, pretreating the substrate to obtain a treated substrate; s3, the processed substrate is fixed above the PZT target in the magnetron sputtering chamber, the chamber is closed, the air pressure in the chamber is pumped to a first pressure value, and the substrate rotating table is opened to enable the substrate to rotate at a constant speed; s4, an air inlet valve is opened, argon is introduced, and the pressure in the cavity is controlled to be within a first pressure range value; s5, turning on a radio frequency power supply, and depositing a thin film within a first power range value to obtain a single-layer PZT thin film; s6, replacing PZT target materials with different components, and repeating the steps S3-S5 to obtain a multi-layer PZT film; and S7, carrying out rapid annealing treatment on the obtained multi-layer PZT film to obtain the prepared PZT multi-layer piezoelectric film. According to the method, the multilayer film is prepared by regulating and controlling the interlayer stress, and the performance of the piezoelectric film is improved, so that the occurrence of breakdown is delayed, and the performance of the film is improved.

The present application relates to a kind of carbon fiber composite reflector mould surface new design method, belong to satellite antenna field;For the thermal deformation in the curing process of reflector, chemical shrinkage deformation and the deformation problem caused by mould, consider the thermal deformation influence of carbon fiber resin matrix composite material from rubber state to glass state whole cycle process, and according to the mould surface compensation of thermal deformation analysis result is carried out.Formation of reflector three-dimensional analysis model;The reflector is according to the rubber state and glass state of corresponding solidification process Double-state whole solidification cycle thermal deformation analysis is carried out, and three-point boundary constraint analysis method is proposed, and it is consistent with the working condition of reflector curing;In the solidification cycle of reflector, the interfacial stress of mould to reflector is extracted, and it is superimposed into reflector thermal deformation and is compensated jointly, through the thermal deformation joint compensation of reflector and mould, the mould surface design for high-precision composite material reflector manufacturing is realized, meet the need of high-precision antenna reflector to surface precision.

The invention relates to an air conditioner aluminum pipe and a preparation method thereof, and belongs to the technical field of aluminum alloy material preparation. Through gradient matching of silicon carbide powder with different particle sizes, silicon carbide with smaller particle sizes is deposited at the bottom of silicon carbide with larger particle sizes, a gradient distribution type filler layer with a compact inner core layer and higher outer shell layer strength is formed, and when an alloy component vibrates, stress is generally concentrated on the surface layer, so that the vibration resistance of the alloy component is improved. The high-strength filler on the surface layer can improve the hardness and crack resistance of the surface layer, and the high-density filler on the core part ensures the toughness of the matrix and balances the crack resistance and impact resistance, so that the interface stress generated by the difference of elastic modulus between the filler and the matrix is avoided, and the risk that the filler matrix interface becomes a fatigue crack source is reduced. And meanwhile, silicon carbide has high hardness, high strength and good heat conductivity. A high-hardness wear-resistant layer can be formed on the surface layer of the alloy material through gradient distribution, wear and crack initiation in the vibration process are resisted, and the anti-vibration fatigue performance is improved.

The present application relates to the technical field of fused deposition manufacturing, and discloses a heterogeneous material manufacturing method with an interfacial staggered overlapping structure. By setting the staggered overlapping interfacial structure, in the process of additive manufacturing of heterogeneous materials, the stress concentration phenomenon of the traditional continuous interface is broken by using the staggered arrangement strategy of the interfacial line of adjacent layers, the interfacial stress is dispersed and transmitted along the three-dimensional direction, and the interfacial bonding strength is strengthened from the geometric structure. At the same time, the active penetration and remelting of material B to material A at the interface are realized through the material rewriting mechanism, the peeling failure risk of the interfacial line caused by insufficient molecular diffusion is avoided, the interfacial staggered amount and the rewriting amount are cooperatively controlled, the definite process constraint boundary is established, the defects of overmelting or weak penetration of materials are prevented, the adaptability of the internal material region and the interfacial transition of heterogeneous materials is ensured, the process fluctuation is reduced, the repeatability of the manufacturing process is improved, and the fatigue resistance and structural bearing capacity of the interfacial line of heterogeneous materials are improved.

This invention discloses a composite exfoliation structure, an exfoliation method, a wafer-level flexible device, and a method for fabricating the same. The composite exfoliation structure includes a stress-regulating layer and a separation layer stacked together. The stress-regulating layer is formed of an elastic or tough material, and the separation layer is formed of a material with weak interlayer bonding. Under the same stress induction, the stress-regulating layer and the separation layer exhibit different deformation amounts and / or deformation modes. The interfacial stress induced by stress in the stress-regulating layer and the separation layer is greater than the interlayer bonding force of the separation layer. Furthermore, the stress-regulating layer, which generates structural deformation, can also induce and regulate the magnitude, direction, and distribution of stress within the separation layer, thereby inducing shear stress and normal stress in the separation layer. These shear stress and normal stress can drive the separation of the layers. This invention avoids the risk of physical damage, improves the uniformity and reliability of exfoliation, and is more suitable for the large-scale fabrication of large-area flexible devices.

The application provides a hard alloy cutter material for high-temperature alloy machining and a preparation method thereof, and belongs to the technical field of hard alloy cutter preparation. The application adopts a cobalt component gradient idea to adjust the hardness of each layer structure, obtains a more wear-resistant high-temperature structure, and low cobalt components can inhibit the mechanical machining sticking of a high-temperature alloy workpiece, realize high-precision and high-efficiency machining, the spraying slurry can improve the interfacial bonding strength between gradient layers, reduce the interfacial stress, and ensure the comprehensive performance of the cutter. The gradient structure is designed to be axisymmetric, which can significantly reduce the internal stress of the structure, improve the performance, increase the usable area of the cutter, and prolong the service life of the cutter. The results of the embodiments show that the hard alloy cutter material has a gradient structure, the fracture toughness is greater than or equal to 12 MPa.m 1 / 2 , the microhardness is greater than or equal to 20.1 GPa, the bending strength is greater than or equal to 3530 MPa, and the high-temperature (1000 DEG C) hardness is greater than or equal to 16.8 GPa.

The application discloses a microneedle fixation strength prediction and calculation method based on virtual simulation and mechanical modeling. The method obtains the geometric data of the connection part of the microneedle needle and handle, and establishes a three-dimensional geometric structure containing the connection interface characteristics. Based on the geometric structure, the elastic modulus, yield strength and fracture strength of the material are determined, and the friction coefficient and adhesive strength are set as the contact characteristic parameters. The finite element grid is constructed and the test working conditions of different pull-out speeds, angles and clamping positions are set. Through simulation calculation, the stress and displacement distribution is obtained, the maximum stress and its position are extracted, and the failure type is judged, and then the interface stress integral is obtained to obtain the pull-out force prediction curve. Combined with the actual pull-out test data, the deviation is calculated, the friction coefficient and the adhesive strength are adjusted repeatedly until the deviation meets the preset precision, and the corrected pull-out force prediction curve and the maximum pull-out force prediction value are output, so that the rapid and non-destructive calculation and evaluation of the microneedle fixation strength are realized.

This invention provides a method for regulating the eutectic reaction mechanism of DBC (Dielectric-Ceramic Composite) substrates, belonging to the field of DBC substrate fabrication technology in power electronic packaging. Addressing the problems of interfacial brittleness, intermetallic compound aggregation, low bonding strength, and poor thermal cycling reliability caused by thermal expansion coefficient mismatch and stress concentration in traditional DBC processes, this invention proposes a three-pronged approach to actively regulate the stress field: interface microstructure guidance, gradient thermal field control, and dynamic mechanical constraint. Through ten steps including substrate pretreatment, microstructure patterning, gradient thermal field construction, dynamic pressure application, in-situ stress monitoring, and segmented cooling, precise spatiotemporal control of the interface stress field is achieved, promoting the formation of a dense and uniform interface layer. Experiments show that the DBC substrate prepared by this invention exhibits over 30% improved interfacial bonding strength and over 2 times improved thermal cycling life. It also demonstrates strong process compatibility and excellent controllability, making it suitable for demanding applications such as high-end power electronic devices.

The present application relates to a kind of based on numerical simulation thermal barrier coating cyclic oxidation failure mechanism research method, steps are as follows: (1) in combination with the control equation of oxygen diffusion to generate aluminum oxide under the cyclic oxidation of thermal barrier coating, establish the growth finite element model of thermal barrier coating under cyclic oxidation;(2) the growth finite element model established in step (1) is combined with constitutive relation, and the growth law of oxidation layer and stress evolution result of thermal barrier coating under cyclic oxidation are simulated by multi-physics field coupling;(3) the stress distribution result of oxidation layer and ceramic layer simulated in step (2) is introduced into the parameter reflecting interface stress state, and the interface crack initiation is evaluated, and coating failure mechanism is analyzed in combination with experimental results.

This invention provides a method for regulating the eutectic reaction mechanism of DBC (Dielectric-Ceramic Composite) substrates, belonging to the field of DBC substrate fabrication technology in power electronic packaging. Addressing the problems of interfacial brittleness, intermetallic compound aggregation, low bonding strength, and poor thermal cycling reliability caused by thermal expansion coefficient mismatch and stress concentration in traditional DBC processes, this invention proposes a three-pronged approach to actively regulate the stress field: interface microstructure guidance, gradient thermal field control, and dynamic mechanical constraint. Through ten steps including substrate pretreatment, microstructure patterning, gradient thermal field construction, dynamic pressure application, in-situ stress monitoring, and segmented cooling, precise spatiotemporal control of the interface stress field is achieved, promoting the formation of a dense and uniform interface layer. Experiments show that the DBC substrate prepared by this invention exhibits over 30% improved interfacial bonding strength and over 2 times improved thermal cycling life. It also demonstrates strong process compatibility and excellent controllability, making it suitable for demanding applications such as high-end power electronic devices.

The present application relates to the field of composite structure design and gear structure design, and more particularly to a multi-material on-demand fixed-point design method based on heterogeneous interface action. To solve the bottleneck of multi-functional collaborative design, the method comprises the following steps: step one, according to the expected demand, using the structure and material type in the database to determine the model type, and establishing a three-dimensional model; step two, using the finite element and micro-scale experiment combination mode for the three-dimensional model, and systematically studying the influence law of heterogeneous interface stress and performance; step three, revealing the action mechanism of interface macro-configuration, microstructure and chemical bond connection, and constructing the theoretical model and design criterion of multi-material heterogeneous interface fusion process; step four, combining the solid-liquid interface fluid dynamics and chemical energy transfer law, and establishing a multi-material digital model; step five, combining the multi-material voxel modeling and three-dimensional gridding technology, and developing a distribution model of adjustable material.

The invention discloses a method for reducing interfacial stress of large-size diamond single crystals grown by a mosaic method. The method is specifically implemented according to the following steps: step 1, selecting a plurality of diamond single crystal substrates of which the sizes are greater than 10mm * 10mm; 2, the diamond single crystal substrate in the step 1 is machined through laser cutting, a plurality of square holes or a rectangular hole is cut in the position close to the edge, and the edge is the splicing edge of the subsequent diamond single crystal substrate; 3, the cut diamond single crystal substrate is cleaned and then spliced, and then O-containing plasma etching treatment is carried out; and 4, growing a continuous epitaxial layer on the surface of the spliced diamond substrate treated in the step 3 by adopting a chemical vapor deposition method, treating by adopting a high-temperature hydrogen atmosphere after the growth is finished, and cutting to obtain the epitaxial layer. According to the method, the to-be-spliced edge of the substrate is cut to form the flexible region, and the possibility of substrate warping is reduced after the epitaxial layer grows, so that the interface stress of the splicing seam is reduced.