156 results about "Negative thermal expansion" patented technology

A deformation-driven additive manufacturing method for a low-interfacial-stress aluminum-steel composite structure comprises the steps that an aluminum alloy thin tube is filled with an adding phase with a low thermal expansion coefficient or a negative thermal expansion coefficient and aluminum-silicon powder used for enhancing the thermal plasticizing fluidity of a raw material wire according to the proportion, and after drying treatment, the raw material wire for adjusting the thermal expansion coefficient is manufactured; a continuous wire feeding friction stir additive manufacturing method is adopted, aluminum alloy raw material wires and adjusting raw material wires are synchronously fed according to the rate proportion changing layer by layer, deposition is driven through deformation, and an aluminum alloy composite transition layer with additive phase components changing in a gradient mode is formed; after the aluminum alloy composite material transition layer is completely prepared, the continuous wire feeding friction stir additive manufacturing method is continuously adopted, and continuous deposition is conducted on the aluminum alloy composite material transition layer to form an aluminum alloy deposition layer; and after deposition manufacturing of the component is completed, subtractive machining treatment is carried out, and a final product is obtained. The invention relates to the technical field of dissimilar material additive manufacturing.

The invention provides an electric heating shock-resistant leading edge and a using method thereof.The electric heating shock-resistant leading edge comprises an outer side skin, a leading edge heating layer, a leading edge inner skin, an energy absorption structure layer, an energy absorption inner skin, ribs and a control module which are sequentially arranged in a stacked mode from outside to inside, the energy absorption structure comprises a Z-shaped body and a supporting body, one end of the supporting body is connected with the end of the Z-shaped body, the other end of the supporting body is connected with a bent portion of the Z-shaped body, the Z-shaped body is connected to the front edge inner skin, the supporting body is made of negative thermal expansion materials, and a probe is arranged at the position, corresponding to the supporting body, of the rib and comprises a pressure sensor and a distance monitor. And the probe and the front edge heating layer are electrically connected to the control module. The electric heating deicing function of bird impact resistance and automatic control of the front edge structure is achieved, the temperature control reliability is improved, the structural weight is reduced, and the technical problems of temperature control, bird impact resistance, structural weight reduction and the like are solved.

The invention provides a composite material for forming a stress release layer, a preparation method of the composite material, an integrated co-fired piezoelectric ceramic actuator and a preparation method of the integrated co-fired piezoelectric ceramic actuator. The method for preparing the composite material for forming the stress release layer comprises the following steps: carrying out ball milling treatment on Bi2O3, Fe2O3, Pb3O4 and TiO2 to obtain precursor powder; the precursor powder is subjected to heat treatment, and BiFeO3-PbTiO3 ceramic powder is obtained; and mixing the BiFeO3-PbTiO3 ceramic powder with the inner electrode metal slurry to obtain the composite material. The internal stress of the actuator is effectively regulated and controlled by utilizing the negative thermal expansion characteristic of the BF-PT ceramic. The elasticity of the inner electrode metal ensures the stress slow-release capability of the inner electrode metal and the outer electrode metal serving as a composite material of a stress release layer, and meanwhile, an effective water vapor barrier is constructed due to the high density of the inner electrode metal.

The invention provides a bifunctional interface lithium-rich manganese-based positive electrode material as well as a preparation method and application thereof, and belongs to the technical field of lithium ion battery positive electrode materials. The bifunctional interface lithium-rich manganese-based positive electrode material comprises a lithium-rich manganese-based layered oxide core particle, an inner negative thermal expansion inorganic layer coating the surface of the lithium-rich manganese-based layered oxide core particle, and an outer fast lithium ion conducting layer coating the outer side of the inner negative thermal expansion inorganic layer. Through the synergistic effect of inner and outer coating layers, mechanical regulation and control and chemical / ion regulation and control are simultaneously realized on the particle size. Compared with a scheme which only adopts an inert coating, a single lithium ion conductive coating or a single negative thermal expansion coating, the method has the advantages that the thermal-chemical-mechanical coupling failure problem of a positive electrode / solid electrolyte interface in the all-solid-state battery can be more comprehensively solved, relatively low interface impedance, smaller voltage attenuation and higher cycling stability are realized, the preparation process is simple, and the preparation cost is low. The method is suitable for large-scale production.

The invention provides a Mn-Fe-Ni-Si-Cu-based negative thermal expansion material as well as a preparation method and application thereof, and belongs to the technical field of negative thermal expansion materials. The negative thermal expansion temperature range of the Mn-Fe-Ni-Si-Cu-based negative thermal expansion material provided by the invention covers the high-temperature and low-temperature ranges (120K-896K), and the high-temperature and wide-temperature-range negative thermal expansion effect is shown; good mechanical properties are achieved; the material has extremely high thermal and mechanical stability, and has important significance for developing high-temperature precision mechanical devices based on zero expansion. The Mn-Fe-Ni-Si-Cu-based negative thermal expansion material disclosed by the invention is low in raw material cost and simple in preparation method.

The application discloses a SiO2-coated negative thermal expansion film and application thereof, and belongs to the technical field of temperature measurement. 12 :Nd 3+ The precursor solution is calcined to obtain the negative thermal expansion film, and then SiO2 solution is added dropwise on the negative thermal expansion film to obtain the SiO2-coated Yb2W3O 12 :Nd 3+ The SiO2-coated negative thermal expansion film is loaded on the opal template. 12 :Nd 3+ As a matrix, the SiO2 coating does not affect the luminescence of the negative thermal expansion film, and makes the Yb2W3O 12 :Nd 3+ The luminescence of the film in the near infrared is significantly enhanced. In addition, compared with the negative thermal expansion material film without the SiO2 coating, the negative thermal expansion material film is more sensitive to temperature.

The present invention relates to the technical field of lithium-ion batteries, and particularly provides a positive electrode sheet and a preparation method therefor, and a lithium-ion battery comprising the positive electrode sheet. The positive electrode sheet comprises a positive electrode active material layer, and the positive electrode active material layer comprises a positive electrode material, a negative thermal expansion material, a conductive agent, and a binder, wherein the characteristic value J of the positive electrode sheet satisfies: 0.001≤J≤0.005. wherein J=R(F) / ρ, R(F) represents the peak intensity ratio between the main peak (F) of the negative thermal expansion material and the (003) characteristic peak of the positive electrode material in the XRD pattern of the positive electrode sheet, and p represents the surface density of the positive electrode sheet, with a unit of mg / cm2.

The invention relates to the technical field of preparation of magnesia-calcium bricks, and provides a thermal expansion compensation magnesia-calcium brick and a preparation process thereof. The magnesia-calcium brick adopts a three-layer gradient structure design and comprises a porous layer, a transition layer and a compact layer, and negative thermal expansion composite particles, neutral thermal expansion adjusting particles and thermosensitive expansion particles are introduced into the formula of each layer to jointly form a thermal expansion compensation system. The bonding strength between layers is enhanced through a mechanical meshing structure of the dovetail grooves and the dovetail protrusions, and interlayer stripping is effectively avoided. The preparation process comprises the steps of raw material surface modification, layered burdening, mold design and charging, segmented temperature control sintering, coordinated cooling and the like. The problems that a traditional magnesia-calcium brick is not matched in thermal expansion and prone to cracking are effectively solved, the thermal shock resistance and structural stability of a brick body are remarkably improved, and the service life of the brick body is remarkably prolonged.

The application discloses a kind of superhigh temperature self-adaptive insulated cable of composite and preparation method thereof, which uses carbon nanotube fiber bundle as conductor, multiple layer aerogel-ceramic nanofiber composite felt as insulator, stress buffer layer formed by negative thermal expansion coefficient material is arranged between layers, and the outer sheath is chemical vapor infiltration SiC carbon fiber braided sleeve.The cable of the application has the advantages of ultra-light, high thermal stability, self-adaptive sealing and strong thermal shock resistance, and is suitable for extreme high temperature environment above 800 DEG C;The preparation method includes supercritical drying, pre-stretching winding and other key processes, to realize the high performance and reliability of the cable.

This invention relates to a glass cover with an outer frame, wherein a flat glass plate is directly joined to the outer frame, wherein the glass matrix within the outer frame comprises at least one of bismuth oxide and boron oxide, and the glass ceramic has a coefficient of thermal expansion of 15 × 10⁻⁶. －7 In the glass ceramics described above, the total volume fraction of the negative thermal expansion filler and the total volume fraction of the filler components are both 40% to 65%, and the softening point of the glass components in the glass matrix is ​​lower than the glass transition point of the flat glass.

Provided are: a resin composition with which it is possible to suppress thermal expansion and impart excellent connection reliability when used as an adhesive for connecting; and a production method therefor. The present invention relates to a resin composition including an epoxy resin, a curing agent, conductive particles, and negative thermal expansion particles, wherein the content of the conductive particles is 0.2-40 mass%, the content of the negative thermal expansion particles is 0.5-30 vol%, and the ratio of the average particle size of the negative thermal expansion particles with respect to the average particle size of the conductive particles (average particle size of the negative thermal expansion particles / average particle size of the conductive particles) is 0.001-10.

The invention belongs to the technical field of thermal switches, and particularly relates to an expansion type thermal switch based on a paper-cut structure, which comprises a thermal expansion paper-cut structure, the thermal expansion paper-cut structure is a central symmetry structure, two ends of the thermal expansion paper-cut structure are fixedly connected through a fixing plate, and the top end of the thermal expansion paper-cut structure is fixedly connected with the bottom end of a fixed heat source; the negative thermal expansion paper-cut structure is of a central symmetry structure, the two ends of the negative thermal expansion paper-cut structure are fixedly connected through a fixing plate, and the bottom end of the negative thermal expansion paper-cut structure is fixedly connected with the top end of the fixed cold source; the thermal expansion paper-cut structure and the negative thermal expansion paper-cut structure are horizontally arranged in parallel, a first gap is reserved between the bottom end of the thermal expansion paper-cut structure and the top end of the fixed cold source, and a second gap is reserved between the top end of the negative thermal expansion paper-cut structure and the bottom end of the fixed heat source. The invention has the advantages of larger thermal stroke, extremely small contact thermal resistance, larger switch ratio and long service life in overheat and overcold space environments.

The invention relates to a three-dimensional heterogeneous integrated interface structure based on hybrid bonding and a stress buffer layer, and belongs to the technical field of semiconductor packaging. The interface structure sequentially comprises a copper-copper bonding layer, a polymer micro bump array, a carbon nanotube vertical interconnection bundle, a bonding interface layer, a stress self-adaptive buffer layer, a topological optimization power grid and a substrate from top to bottom, wherein an embedded coaxial interconnection structure and a graphene electromagnetic isolation wall are arranged in the topological optimization power grid. Wherein the stress self-adaptive buffer layer is formed by manufacturing polymer micro-lattices on the surface of the bonding interface layer, filling the micro-lattices with a mixture of negative thermal expansion ceramic particles and epoxy resin, and embedding shape memory alloy micro-springs. And the chip is bonded with the interface structure through the copper-copper bonding layer. The device has the advantages of being high in interconnection density, good in mechanical reliability and excellent in signal integrity, and high-performance three-dimensional heterogeneous integration can be achieved.

Embodiments of the present disclosure relates to a composite material, a working stamp, and a preparation method thereof. The composite material includes a polymer matrix, a plurality of SMA nanoparticles, and a plurality of NTE material nanoparticles. The SMA nanoparticles are dispersed in the polymer matrix. The NTE material nanoparticles are dispersed in the polymer matrix. At a first temperature, the composite material is in a cured state and a thermal expansion coefficient of the composite material is zero (0) or near zero. When the composite material is cooled from the first temperature to a second temperature, the composite material spontaneously contracts caused by phase transformation of the SMA nanoparticles.

This invention discloses a through-silicon via (TSV) capable of suppressing copper extrusion and its fabrication method. The invention utilizes magnetron sputtering to deposit a certain thickness of ZrW at the bottom of the TSV. 2‑x Mo x After depositing an O8 thin film, followed by electroplating a copper layer of a certain thickness, the above steps are repeated to deposit multiple layers of ZrW in the middle of the Cu. 2‑x Mo x O8 thin film; while ZrW 2‑x Mo x O8 is a material with a negative coefficient of thermal expansion, which is -4.3 × 10⁻⁶. ‑6 to -7.7×10 ‑6 K ‑1 This material contracts rather than expands when heated. During heat treatment (e.g., annealing) or temperature cycling of through-silicon vias (TSVs), Cu expands, while ZrW... 2‑x Mo x The O8 material shrinks rather than expands, which can partially offset the thermally induced stress caused by the mismatch in the coefficients of thermal expansion between the constituent materials of the through-silicon via (TSV). Therefore, the TSV fabricated by the method of this invention can improve the reliability of copper-filled TSVs while allowing for optimized device performance (e.g., allowing for higher temperature annealing of copper).

The application provides a PrMnO3-based negative thermal expansion material and a preparation method, and belongs to the technical field of negative thermal expansion materials. The negative thermal expansion material is of an orthogonal phase Pnma structure and a 3D cross Mn-O bond network. The negative thermal expansion temperature range of the negative thermal expansion material can be adjusted by adjusting the amount of Bi ions replacing Pr ions. The addition amount of the Bi ions satisfies that the ratio of the molar amount of the Bi ions to the molar amount of A-site ions is less than 50%. The application introduces Bi 3+ for the first time in the A-site of pure PrMnO3 3+ , and directionally introduces a "Bi 2 6s 2 lone pair electron functional site" in the crystal lattice. The PrMnO3-based negative thermal expansion material stably maintains the orthogonal phase Pnma structure and the 3D cross Mn-O bond network, and achieves the purpose of mildly and accurately controlling the negative thermal expansion temperature range.

This invention provides an extension film for FC-BGA encapsulation substrates containing a negative thermal expansion material, its preparation method, and its application. The extension film comprises the following components in parts by weight: 50-60 parts epoxy resin, 5-10 parts phenoxy resin, 30-35 parts curing agent, 70-80 parts inorganic filler, and 10-20 parts phase change negative thermal expansion material. The preparation method includes the following steps: mixing the components of the extension film evenly, coating it onto a substrate, and drying to obtain the extension film. By using inorganic filler and a phase change negative thermal expansion material, this invention produces an extension film with a low coefficient of thermal expansion, suitable for preparing FC-BGA encapsulation substrates.

The object of the present invention is to provide a negative thermal expansion material that consistently exhibits excellent negative thermal expansion characteristics over a wide temperature range of -30 to 150°C, and shows a more gradual volume decrease with increasing temperature compared to Zn2P2O7 between 100 and 150°C. The negative thermal expansion material of the present invention is characterized by containing 5 to 90 parts by mass of zinc pyrophosphate per 100 parts by mass of copper pyrophosphate, wherein the BET specific surface area of ​​the copper pyrophosphate is 0.2 to 8.0 m². 2 The BET specific surface area of ​​the zinc pyrophosphate is 0.2 to 8.0 m² / g. 2 It is preferable that it be / g.

The invention discloses an anti-warping IC carrier plate with an edge supporting structure, and the anti-warping IC carrier plate remarkably reduces the warping deformation of a substrate through the design of edge special holes and thermal mechanical compensation. The H-shaped copper column frame and the gradient aperture / spacing design can compensate according to the asymmetry degree of a substrate pattern, so that the warping of the whole board is reduced; v-shaped or Y-shaped holes are designed according to angles, directional support and bending moment resistance are generated, and corner warping is particularly restrained; a shape memory polymer (SMP) or a thermal shrinkage and cold expansion insert containing a negative thermal expansion (NTE) filler is embedded in a specific position, shrinks at a high temperature to enable the substrate to normally release residual stress, and recovers the supporting property at a room temperature; the existing process of the PCB is continued, special equipment does not need to be newly added, and mass production is easy; under the double compensation of the structure and the material, the metal / polymer in the substrate is crystallized in a low-stress environment, and the overall stability of the substrate is improved.

The invention discloses a battery packaging structure, a preparation method thereof and a battery. The battery packaging structure comprises a battery shell, and a first coating layer and a second coating layer are sequentially arranged on the inner side of the battery shell from inside to outside; the first coating layer is a negative thermal expansion alloy layer; and the second coating layer comprises a metal organic framework material and a negative thermal expansion inorganic compound. The battery packaging structure prepared by the invention can effectively inhibit the volume expansion of the battery in the charging and discharging process, and improves the structural stability, safety and electrochemical performance of the battery.

The invention belongs to the related technical field of metamaterials, and discloses a design method and a product of a zero / negative thermal expansion coefficient metamaterial made of a single solid material. The method comprises the following steps: dividing a design domain into a high-pressure gas region, a low-pressure gas region and a solid region, wherein the solid region is used for isolating the high-pressure gas region from the low-pressure gas region; setting a thermal expansion coefficient and an elastic modulus of the solid area; adjusting the form of the solid region and the air pressure of the gas region so that the deformation of the solid region generated under the pressure difference between the high-pressure gas region and the low-pressure gas region is equal to zero heat or negative thermal expansion of the solid region generated under the temperature change under the condition that the temperature in the design region is changed; in this way, the required form and air pressure of the solid area are obtained. According to the invention, the thermal expansion performance is accurately regulated and controlled, and the method is suitable for application scenes with high requirements on size thermal stability, such as aerospace and precise instruments.

This invention relates to the field of fiber optic sensing technology, specifically to a method for fabricating a low-temperature temperature-sensitive fiber grating based on a negative thermal expansion material coating, and the low-temperature temperature-sensitive fiber grating structure thereof. The method includes the following steps: preparing and pre-treating an optical fiber core layer; coating the outer periphery of the optical fiber core layer with nano-sized zirconium hafnium to obtain a stress transfer layer; preparing a low-temperature negative thermal expansion coefficient sensitizing material powder and coating it on the outer periphery of the optical fiber stress transfer layer to obtain a negative thermal expansion material sensitizing coating layer; constructing a porous structure on the surface of the obtained negative thermal expansion material sensitizing coating layer to form a porous layer on the surface of the negative thermal expansion material; and encapsulating a composite shell structure on the outside of the porous layer on the surface of the negative thermal expansion material to obtain a metal sheath layer. The fiber grating structure provided by this invention, for adapting to the production of temperature sensors, can simultaneously solve the failure problems of traditional sensors in the 4K ultra-low temperature region, the interference problems of electrical sensors in strong electromagnetic field environments, and the sealing failure problems caused by material brittleness in cryogenic environments.

A seal energization assembly, including a seal, a setting arrangement in operative contact with the seal, and a set energy compensation device disposed in operative contact with the seal and add energy to the setting arrangement responsive to a falling environmental temperature. A method for maintaining energy in a seal during temperature down cycling, including automatically compensating for temperature related reduction in the seal energy by expanding a set energy compensating device in contact with the seal. A packer, including a mandrel, a seal on the mandrel, and a setting arrangement in operative contact with the seal, the arrangement including a negative thermal expansion set energy compensation device. A wellbore system, including a borehole in a subsurface formation, a string in the borehole, and a seal energization assembly, disposed within or as a part of the string.

The application discloses a mineral casting and a preparation method and application thereof, and belongs to the technical field of mineral casting. The mineral casting provided by the application is embedded with isotropic negative thermal expansion material. By embedding the isotropic negative thermal expansion material in the mineral casting, the thermal expansion coefficient of the mineral casting is reduced, the manufacturing precision is improved, and the isotropy of the obtained mineral casting is good, the deformation amount in each direction is uniform, and the mineral casting has wide application in machine tool manufacturing, building or transportation.

The invention provides an application of LaCo < 0.6 > Ni < 0.4 > O < 3-delta > (LCN) and a negative thermal expansion material in a solid oxide electrolytic tank. The LCN and the negative thermal expansion material are used in the solid oxide electrolytic tank, the overall thermal expansion coefficient of the composite powder can be accurately adjusted through the cooperative regulation effect of positive expansion and negative expansion, the composite powder is matched with a galvanic pile assembly, the problem of interface thermal stress is solved, adverse reaction between the composite powder and the LCN can be effectively avoided, and the service life of the solid oxide electrolytic tank is prolonged. And the long-term performance stability of the composite powder is ensured. Positive expansion of LCN is compensated by utilizing the thermal shrinkage and cold expansion characteristics of the negative thermal expansion material, and the overall thermal expansion behavior is regulated and controlled through the stress containment effect of a two-phase interface, so that the thermal expansion coefficient of the composite powder is regulated and controlled to be matched with the thermal expansion coefficient of an SOEC electrolyte and other components, and then thermal stress is reduced; and the structural stability and reliability in the high-temperature operation process are improved.

Provided is a powder comprising a negative thermal expansion material including a compound represented by general formula (1): Znx1Tx2Py1Ay2Oz (T includes at least one element selected from among Li, Mg, Al, Si, Ca, Sr, Ba, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ce, Ta, W, Bi, B, Na, K, F, Cl, Br, I, Hf, Y, Yb, S, Mo, Te, Pb, Cd, Te, Nd, Sm, Eu, Tb, Dy, and Ho, A includes at least one element selected from among Li, Ca, Sr, Ba, Al, Si, V, Ge, Sn, La, Ce, Y, Pr, Nd, and Sm, 0 ≤ x2 < 2, 0 ≤ y2 ≤ 2, 1.7 ≤ x1 + x2 ≤ 2.3, 1.7 ≤ y1 + y2 ≤ 2.3, and 6 ≤ z ≤ 8). The powder has a 90% volume-frequency particle diameter (D90) of 50 μm or less.

The invention belongs to the technical field of negative thermal expansion materials, and discloses a negative thermal expansion material and a preparation method and application thereof. And the negative thermal expansion material is Cu3 (MoO4) 2 (OH) 2. The nano-sheet alkali Cu3 (MoO4) 2 (OH) 2 with the negative thermal expansion characteristic not only can tolerate higher temperature, but also has a wide NTE temperature range of the negative thermal expansion material.

This invention provides a diamond and negative thermal expansion particle-reinforced aluminum matrix composite material and its preparation method, belonging to the field of composite material technology. The aluminum matrix composite material consists of a diamond phase and a negative thermal expansion phase dispersed in an aluminum matrix; the average particle size of the diamond phase is 10-1000 μm, and the ratio of the average particle size of the diamond phase to the average particle size of the negative thermal expansion particles is 10-20; the particle size of the negative thermal expansion particles adjacent to the diamond phase is smaller than that of the negative thermal expansion particles farther from the diamond phase. By controlling the volume fraction of diamond and negative thermal expansion particles, a diamond and negative thermal expansion particle-reinforced aluminum matrix composite material with excellent thermophysical properties is obtained. Through a synergistic optimization strategy, a thermal expansion coefficient matching that of semiconductor materials is obtained, which can be applied in the field of electronic packaging heat dissipation materials.

The invention belongs to the technical field of millimeter wave therapeutic instruments, discloses a wearable millimeter wave therapeutic instrument heat dissipation device and a heat management assembly, and particularly relates to a wearable millimeter wave therapeutic instrument heat dissipation device which comprises an adjusting assembly, a therapeutic assembly is connected to the adjusting assembly, and an auxiliary assembly is connected between the therapeutic assembly and the adjusting assembly. The two ends, distributed in the width direction, of the adjusting assembly are connected with the constraint assemblies correspondingly, the ends, away from the adjusting assembly, of the constraint assemblies are connected with the fixing assemblies, and the vent holes, the communicating grooves and the heat dissipation grooves which are made of negative thermal expansion materials are formed, so that a complete heat dissipation channel is constructed; and when the temperature in the working cavity rises, the heat dissipation function can be automatically started, and heat can be quickly conducted out. According to the design, the temperature in the working cavity is effectively reduced, the heat dissipation efficiency is improved, and the stability and reliability of equipment in the long-time use process are ensured.

The application discloses a preparation method of a low-expansion high-toughness composite oxide solid electrolyte, which comprises the following steps: S1: compounding a solid electrolyte precursor, a grain boundary toughening agent and a stress buffer into a composite powder; S2: mixing the composite powder with a negative thermal expansion filler to prepare a plurality of mixed powders with a gradient change in the content of the negative thermal expansion filler; S3: preparing a green body from the plurality of mixed powders, and making the negative thermal expansion filler form a concentration gradient in the green body along the thickness direction; and S4: sintering the green body, making the grain boundary toughening agent form a toughening phase at the grain boundary in the sintering process, and finally obtaining the low-expansion high-toughness composite oxide solid electrolyte. The preparation method can make the oxide solid electrolyte have low thermal expansion, high fracture toughness, high density and self-healing characteristics, and can meet the strict requirements of long-term durability and reliability of electrolytes in a wide temperature range, long service life and high-power solid-state batteries.