348 results about "Low melting point" patented technology

The invention discloses a method for preparing an ultrahigh-temperature ceramic coating by an ultrahigh-temperature metal gas source based on a molten salt medium, which comprises the following steps of: mixing low-melting-point salt A, metal fluoride and metal M to obtain a mixture C, putting the mixture C into a first crucible, mixing low-melting-point salt B and metal M to obtain a mixture D, putting the mixture D into a second crucible, putting a carbon base material into a deposition furnace, and performing vacuum drying to obtain the ultrahigh-temperature ceramic coating. Heating the first crucible to melt the mixture C to obtain a melt E, and heating the second crucible to melt the mixture D to obtain a melt F; carrier gas is guided into the first crucible, the carrier gas flow passes through the melt E to form gas flow containing a metal gas source, the gas flow containing the metal gas source is guided into the second crucible, and the gas flow containing the metal gas source is filtered by the melt F in the second crucible to form a pure metal reaction gas source, and finally, a pure metal reaction gas source is introduced into the deposition furnace for deposition of the carbon base material, and the ultra-high-temperature ceramic coating is obtained. The method is easy to operate and low in cost.

The invention discloses an aluminum-based composite material and a preparation method thereof. The preparation method comprises the following steps: firstly, mixing powder of an intermediate alloy, a simple substance metal and a reinforcement with a binder, and carrying out cold pressing to form a green body; degreasing and sintering the green body to obtain a sintered part; and heating the sintered part, performing closed die forging, performing heat treatment and fine trimming to obtain a finished product, and if the performance does not meet the requirements, performing hot extrusion on the sintered part, and performing heat treatment and fine trimming to obtain the finished product. Oxide is removed through ball milling, the surface of the Al-Mg powder is activated, and passivation is protected through a binder; a reinforced phase SiC is designed to be blended with a binder, and then the mixture is mixed with other powder to form a specific microstructure; low-melting-point Sn is introduced to limit the sintering temperature, element diffusion is promoted through a liquid phase, and generation of a harmful intermediate phase is avoided; a sintered part with the density being 80-95% is adopted, a low-strain soft area is formed around a reinforced phase in cooperation with a specific microstructure, deformation coordination is improved, meanwhile, the peak aging time of the aluminum alloy is prolonged through SiC, the electric conduction and heat conduction performance is improved, and the comprehensive performance of the composite material is comprehensively improved.

The invention belongs to the technical field of thermal power heating surface treatment, and provides a gradient functional composite coating applied to a boiler heating surface and a preparation method of the gradient functional composite coating in order to solve the technical problems that an existing protective coating of the boiler heating surface is prone to abrasion and oxidation and high in cost. Collaborative design is formed, and gradient matching of mechanical properties and environmental failure resistance is achieved. The low-melting-point glass powder is combined with the rare earth catalytic effect, low-temperature ceramization is achieved, and thermal damage to a matrix is avoided. After the metal ceramic transition layer is sprayed, high-frequency induction remelting treatment is carried out, meanwhile, laser cladding is carried out on the surface of the ceramic surface layer, a nanocrystalline-amorphous composite structure is formed, and the bonding strength of the coating is improved.

The invention discloses a method for improving performance of rare earth permanent magnet sintered neodymium iron boron grain boundary diffusion, and belongs to the technical field of rare earth permanent magnet materials. The method comprises the steps that a low-melting-point metal layer and a diffusion layer containing heavy rare earth elements are sequentially formed on the surface of a clean sintered neodymium-iron-boron magnet, and then vacuum diffusion heat treatment and tempering treatment are conducted. Wherein the low-melting-point metal layer comprises at least one of copper, aluminum, gallium and tin or an alloy of the copper, the aluminum, the gallium and the tin; the heavy rare earth element comprises at least one of dysprosium, terbium, holmium and gadolinium. The low-melting-point metal layer is preferentially diffused and wets the grain boundary in the heat treatment process, heavy rare earth elements are promoted to be deeply and uniformly diffused towards the interior of the magnet along the grain boundary, so that a heavy rare earth-rich shell layer is formed outside main phase grains of the magnet, and the intrinsic coercive force is improved; meanwhile, the low-melting-point metal forms a strengthening phase at the grain boundary, the brittleness of the magnet after diffusion is improved, the surface corrosion phenomenon is restrained, and collaborative optimization of the comprehensive performance of the magnet is achieved.

The invention discloses a high-Al and Ti difficult-to-deform high-temperature alloy hot working method, which avoids the melting risk of low-melting-point intermetallic compounds through high-temperature diffusion on one hand, and can realize effective and uniform diffusion of chemical elements on the other hand; on the other hand, through gradual heating number cooling forging, a high-temperature small-deformation forging process is carried out in an as-cast structure interval, and a low-temperature large-deformation process is adopted after the as-cast structure is crushed, so that an ideal uniform and fine recrystallized grain structure is finally realized, and the problems of high possibility of cracking, non-uniform forging structure, coarse grains and the like in a high-temperature alloy forging process are solved; and the high-quality requirement for use of downstream aero-engine components is met.

The invention provides a high-thermal-conductivity and high-adhesion thermal interface material and a preparation method thereof, and belongs to the technical field of thermal interface materials. The thermal interface material is prepared by in-situ cross-linking reaction of the following components: a polymer matrix comprising a polymer containing active functional groups and a cross-linking agent; the heat-conducting filler accounts for more than 90wt% of the total weight of the thermal interface material; the low-melting-point organic medium accounts for 0.1-5wt.% of the total weight of the thermal interface material, and the melting point of the low-melting-point organic medium is lower than the crosslinking curing temperature of the polymer matrix; wherein the heat-conducting filler forms a continuous three-dimensional heat-conducting path in a cross-linked polymer network, and the low-melting-point organic medium is uniformly dispersed in the network. Under the ultrahigh filler content, high bulk phase thermal conductivity and high initial viscosity are realized at the same time, and the contradiction between high thermal conductivity and high interface contact resistance is solved. The high viscosity at room temperature is beneficial to operation and storage, and is softened due to melting of an organic medium at the working temperature of a device, so that the interface wettability is dynamically enhanced, and the contact thermal resistance is minimized.

The invention discloses a packaging material as well as a preparation method and application thereof. The packaging material comprises the following components in parts by mass: 40-85 parts of matrix resin, 5-30 parts of phase change PCM particles, 3-20 parts of self-repairing microcapsules, 1-8 parts of an interface compatilizer and 10-20 parts of a heat-conducting network reinforcing material, the melting point of the phase change PCM particles is not more than 80 DEG C; a core layer of the self-repairing microcapsule comprises dicyclopentadiene and a ruthenium catalyst, and a shell layer of the self-repairing microcapsule comprises polyurea or polyurethane; the PCBA packaging material with the intelligent response function is formed by combining the low-melting-point phase-change PCM particles with the self-repairing microcapsule system, when the PCBA temperature is too high, the low-melting-point phase-change PCM particles are molten, junction temperature suddenly rising is restrained through melting heat absorption, meanwhile, the adjacent microcapsules are triggered to be broken through volume expansion, DCPD monomers are released and subjected to in-situ polymerization under the action of a catalyst, and the PCBA packaging material with the intelligent response function is obtained. Microcracks generated by thermal stress are rapidly repaired, and the heat dissipation stability and the electrical insulation reliability of the material in long-term thermal circulation are remarkably improved.

The invention belongs to the technical field of preparation of soft magnetic composite materials, and particularly relates to an insulation coating method and application of a soft magnetic powder material. The insulating coating method comprises the following steps: (1) uniformly mixing low-melting-point metal or alloy powder with silica sol, a silane coupling agent and a thermocuring resin glue solution to obtain coating slurry; and (2) uniformly mixing soft magnetic powder with the coating slurry obtained in the step (1), firstly performing hot-pressing curing molding at the temperature of 60-100 DEG C under a vacuum condition, and then performing hot-pressing sintering treatment at the temperature higher than the melting point temperature of low-melting-point metal or alloy powder and under an oxygen-containing atmosphere condition to obtain the insulated and coated soft magnetic powder material. According to the insulating coating method, the advantages of an organic material insulating coating method and an inorganic material insulating coating method are combined, the defects of the organic material insulating coating method and the inorganic material insulating coating method are overcome, and the stability and the insulating coating effect of the insulating coating layer are remarkably improved.

The invention discloses a high-strength and high-plasticity low-melting-point aluminum alloy brazing material and a preparation method and application thereof, and relates to the technical field of solder manufacturing. The low-melting-point aluminum alloy welding flux is prepared from the following components in percentage by weight: 10 to 14 percent of Si, 4 to 20 percent of Cu, 0.04 to 0.25 percent of Eu, 0.78 to 0.82 percent of Fe, 0.13 to 0.17 percent of Mn, 0.08 to 0.12 percent of Mg, 0.18 to 0.22 percent of Zn and the balance of aluminum and inevitable impurities. The Al-Si-Cu ternary alloy is constructed to form a low-melting-point eutectic phase, the melting point of the material is effectively reduced, meanwhile, Eu atoms are doped, the aluminum matrix is subjected to the pressure stress effect, the interplanar spacing is reduced, the grain size of the matrix aluminum phase is reduced, the elemental Si phase is refined, the eutectic Al-Si phase content is increased, and precipitation of the brittle Al2Cu phase is restrained; therefore, the aluminum alloy solder has high tensile strength and elongation after fracture under the condition that the melting point is low.

A braze tape includes a first portion, a second portion, and a central portion located between and adjacent to the first portion and the second portion. The first portion includes a low melting temperature alloy material, the second portion includes a high melting temperature alloy material, and the central portion includes a mixture of the low melting temperature alloy material and the high melting temperature alloy material. The central portion may gradually change between the low melting temperature alloy material and the high melting temperature alloy material. A related method is also disclosed.

The invention relates to the technical field of carbon dioxide geological utilization and storage, in particular to a sealing evaluation device and method for a low-melting-point alloy shaft plugging material, and the device comprises an observation cylinder, an outer cylinder, a simulation shaft, a gas channeling simulation mechanism, a formation pressure adjusting mechanism, a cooling mechanism, a shaft pressure adjusting mechanism and an image acquisition unit. The device is reasonable and compact in structure, alloy materials in the simulation wellbore are in an alloy melting stage, the sealing ejector pin prevents liquid alloy from flowing into the first gas injection hole, and after the alloy materials in the simulation wellbore are solidified, the sealing ejector pin is moved downwards, so that the upper end of the sealing ejector pin is located below the first gas injection hole, and the gas channeling simulation mechanism is communicated with the lower portion of the simulation wellbore; when the formation pressure adjusting mechanism works, the formation pressure adjusting mechanism is connected with the confining pressure cavity through the pressurizing hole, the simulation effect on the formation pressure around the simulation shaft can be achieved, the heating melting-cooling forming process of the low-melting-point alloy material is achieved, and the sealing capacity of the alloy plug-sleeve combination body under the actual underground working condition is evaluated.

The invention discloses a low-melting-point high-strength hypoeutectic magnesium alloy and a preparation method thereof. The magnesium alloy comprises the following components in percentage by mass: 12.0-14.0% of Zn; 0 to 0.8 percent of Ca; 0.3 to 0.8 percent of Zr; the balance is Mg and inevitable impurities; the content of Ca is not 0, and the melting point of the magnesium alloy is not higher than 340 DEG C. By accurately controlling the addition amount of Ca and the ratio of Ca to Zn and assisting with the grain refinement effect of Zr, formation of a fine and dispersively-distributed second phase is successfully promoted in the alloy, the elongation of the obtained magnesium alloy is kept above 8%, and the elongation of the magnesium alloy is greatly improved while the basic requirement of engineering application for plasticity is met. The yield strength and the tensile strength of the Mg-Zn alloy are greatly and synchronously improved at the room temperature and the high temperature, the inherent defect that the absolute strength of a traditional low-melting-point Mg-Zn alloy is insufficient is effectively overcome, finally, ideal combination of low melting point, high strength and good plasticity is achieved, and the urgent requirement for high-performance sacrificial structural parts in the fields of aerospace and the like is met.

The application discloses a multi-component carbon fiber reinforced composite material and a low-temperature infiltration preparation method. The reaction infiltration technology is adopted, a low-melting-point infiltrant is used as a carrier, a high-melting-point component is introduced into the C / C composite material at low temperature, different components are enriched in different regions according to the reaction rate difference of each component and pyrolytic carbon, the internal content of the low-melting-point phase is reduced, and the ablation resistance is improved.

The invention belongs to the field of nuclear fuel, and particularly discloses a metal material for fuel rod gap filling and a preparation method of the metal material. The metal material comprises the following components in parts by mass: 0.01 to 44.5 parts of lead, 0.01 to 56.5 parts of bismuth, 0.01 to 61.9 parts of tin, 0.01 to 5 parts of magnesium and 0.01 to 5 parts of zirconium; and the melting point of the metal material is less than 300 DEG C. The metal material disclosed by the invention has a lower melting point and a higher heat conductivity coefficient, is applied to the in-pile service process of the fuel rod of the advanced reactor, is molten at a loop temperature to be in a liquid state, fills a gap, immerses and seals a fuel core block section, and serves as an excellent heat-conducting medium, so that heat transfer between the fuel rod core block and a cladding is realized, and the heat transfer efficiency is improved. The core block and the cladding are combined to reduce the temperature of the nuclear fuel, meanwhile, the gasification phenomenon does not exist, the phenomenon of irradiation swelling-fission gas release does not occur, the contact force between the core block and the cladding is reduced, and the service life of the fuel rod is prolonged.

The present application relates to the preparation method of thick polycrystalline diamond compact for oil and gas drilling, which comprises the following steps: mixing two or more kinds of diamond powder with impurities removed; sand blasting the cemented carbide substrate; sequentially loading the impurity storage layer, the diamond powder mixture layer, the low-melting-point metal sheet, the cobalt sheet and the cemented carbide substrate into a high-temperature-resistant metal cup; placing the high-temperature-resistant metal cup into a synthetic block and then into a six-surface press; performing two-stage high-temperature and high-pressure sintering, wherein the first stage is sintering at a pressure of 5.5-5.8 GPa and a temperature of 800-1300 DEG C for 60-150 seconds, and the second stage is sintering at a pressure of 6-8 GPa and a temperature of 1490-1580 DEG C for 450-700 seconds; and taking out at room temperature and normal pressure. The impurity storage layer, the low-melting-point metal sheet and the cobalt sheet are arranged, and the high-temperature and high-pressure scanning sintering method is adopted, so that the thickness of the diamond layer reaches 3-4 mm after sintering, and the service life is greatly prolonged.

The invention relates to an MXene / low-melting-point alloy electromagnetic shielding layered composite material as well as a preparation method and application thereof. Comprising the following components in percentage by mass: 40-90% of low-melting-point alloy powder, 5-40% of an MXene filler and 5-20% of a chelating agent. The layered composite material can effectively form an electron transmission channel and improve conductivity and electromagnetic shielding performance. Under the action of the low-melting-point alloy, the layered composite material can show more excellent electromagnetic shielding performance and compressive strength, the highest electromagnetic shielding effectiveness of the layered composite material is larger than 64 dB, and the highest compressive strength of the layered composite material is larger than 65 MPa. The electromagnetic shielding material has the advantages of simplicity and convenience in preparation, excellent performance, low cost, easiness in commercial application and the like, and can be widely applied to the fields of electronic equipment, communication industry, medical equipment, automobile industry, aerospace and the like as an excellent electromagnetic shielding material.

The application belongs to the technical field of soft magnetic composite material preparation, and particularly relates to an insulation coating method for soft magnetic powder material and application. The insulation coating method comprises the following steps: (1) uniformly mixing low-melting-point metal or alloy powder, silica sol, silane coupling agent and hot curing resin glue solution to obtain coating slurry; (2) uniformly mixing soft magnetic powder and the coating slurry of step (1), and then performing hot-pressing curing forming at a temperature of 60-100 DEG C and under vacuum condition, and then performing hot-pressing sintering treatment under a temperature higher than the melting point of the low-melting-point metal or alloy powder and under an oxygen-containing atmosphere condition to obtain the insulation-coated soft magnetic powder material. The insulation coating method of the application combines the advantages of the organic material insulation coating method and the inorganic material insulation coating method, overcomes the respective defects, and significantly improves the stability and insulation coating effect of the insulation coating layer.

The application discloses a method for brazing ferrite and copper based on a nano-silver and glass phase composite filler, which is used for realizing the welding of ferrite and copper, and the method comprises the following steps: S1, preparing a paste based on nano Ag powder and a low-melting-point glass phase; S2, pretreating the ferrite and copper to be brazed, coating the paste on the surfaces to be welded of the ferrite and copper to be brazed, and assembling to form a ferrite-copper assembly; and S3, heating and brazing the assembled ferrite-copper assembly. The application has the advantages of high connection strength and good heat conductivity.

Provided is a laminate which comprises a base material, a first heat-conducting layer that is provided on the base material and contains an epoxy resin, an epoxy resin curing agent, and first heat-conducting particles, and a second heat-conducting layer that is provided on the first heat-conducting layer and contains a curing component, a curing agent that cures the curing component, second heat-conducting particles, and a low-melting-point metal. The first heat conduction layer does not contain the low melting point metal.

The resin composition molded body (10) disclosed herein is a molded body comprising a resin substrate (11) containing a low-melting-point resin, cellulose-based material particles (12) dispersed in the resin substrate 11, and non-low-melting-point resin particles (13) dispersed in the resin substrate (11). The low-melting-point resin has a melting point in the range of 80°C or higher and less than 190°C, and the content of the low-melting-point resin is in the range of 10 to 80% by mass relative to the total amount of the composition. The content of the cellulose-based material particles (12) is in the range of 10 to 50% by mass relative to the total amount of the composition. The non-low-melting-point resin particles (13) comprise one or both of a high-melting-point resin with a melting point of 190°C or higher and a thermosetting resin. The content of the non-low-melting-point resin particles (13) is in the range of 10 to 80% by mass relative to the total amount of the composition.

The present application belongs to the field of dissimilar metal laser welding, and particularly relates to a method for improving the gap adaptability of dissimilar metal butt joint laser brazing by alternating magnetic field. By setting the butt joint part of the dissimilar metal test plate with assembly gap suspended at the bottom, applying transverse alternating magnetic field and inert gas protection below it, and setting the laser welding head above the sample and the magnetic field generating device below the sample to remain stationary during the welding process, and the laser beam is offset to the low melting point metal side, the molten low melting point material wets and spreads on the surface of the un-molten high melting point material, and then interface metallurgical bonding occurs to form a brazing joint. The present application improves the assembly gap adaptability of dissimilar metal butt joint laser brazing based on the effect of transverse alternating magnetic field lifting the molten pool, suppresses the generation of aluminum alloy weld side heat cracks and other defects caused by the increase of assembly gap, improves the weld forming, and improves the adaptability of dissimilar metal butt joint laser brazing in engineering.

A probe card for probing a semiconductor substrate is disclosed. The probe card can include a probing element having a hybrid bonding surface that is configured to removably hybrid bond to a semiconductor element. The hybrid bonding surface of the probing element can include a nonconductive layer and contact pads at least partially embedded in the nonconductive layer. The contact pads of the probing element can be bonded to probe pads of the semiconductor element. Additionally, the nonconductive layer of the probing element can be bonded to a nonconductive layer of the semiconductor element. A conductive material can be deposited over the contact pads. The conductive material can comprise a lower melting point than the contact pads. The conductive material can comprise at least one of a low melting point metal and conductive polymer.

A substrate processing apparatus includes: a tray provided in a vacuum processing container and having a recess that accommodates a target made of a low-melting-point material; a refrigerator that cools the tray; a substrate holder that holds a substrate; a reversal driver that reverses the position of the substrate holder upside down; and a rotation driver that rotates the substrate holder in a circumferential direction of the substrate.

The present invention provides a transient liquid phase diffusion bonding preform, and a transient liquid phase diffusion bonding method and a power module using same, the preform having a unidirectional porous metal body applied thereto and thus facilitating high-temperature bonding. The transient liquid diffusion bonding preform to which a unidirectional porous metal body is applied, according to an embodiment of the present invention, comprises: a unidirectional porous metal body having a plurality of unidirectional pores extending in one direction from a first surface to a second surface and made of a high-melting point metal; a first surface layer disposed on the first surface of the unidirectional porous metal body and made of a low-melting point metal; a second surface layer disposed on the second surface of the unidirectional porous metal body and made of the low-melting point metal; and a pore-filling layer for filling at least a portion of the plurality of unidirectional pores of the unidirectional porous metal body and made of the low-melting point metal.

The invention relates to the technical field of heat dissipation materials, in particular to a Bi-In-Sn liquid metal phase change material for chip heat dissipation, a preparation method and a heat dissipation device, and is technically characterized in that the liquid metal phase change material is prepared from the following elements in percentage by mass: 42.0%-48.0% of Bi, 33.0%-40.0% of In and 12%-25% of Sn; the preparation method comprises the following steps: weighing Bi, In and Sn metal particles, and sequentially carrying out acid pickling, ultrasonic cleaning and drying treatment; under the high-purity argon protection environment, the pretreated metal particles are subjected to vacuum melting and stirring, and uniform liquid alloy is formed; and after the liquid alloy is cooled and formed, ultrasonic treatment is conducted, the Bi-In-Sn liquid metal phase change material is prepared, the advantage of low melting point is kept, meanwhile, unexpected improvement of latent heat performance is achieved, and the bottleneck problem of instantaneous thermal runaway of a chip in an extreme environment is effectively solved.

The invention provides a method for calculating the oxidation rate of low-melting-point metal (Bi) by using a Raman spectrum. By controlling the sintering temperature of the metal Bi and using the Raman spectrum peak ratio, the oxidation rates of the metal Bi at different temperatures are calculated. Through contrastive analysis, the result is consistent with the results of differential thermal thermogravimetry, X-ray diffraction analysis and the oxidation rate of the atomic ratio of a scanning electron microscope, but Raman spectrum analysis is simpler, more convenient and more accurate. The method is mainly applicable to the field of material detection and analysis.

The invention discloses a samarium-cobalt magnet and a preparation method thereof. The samarium-cobalt magnet takes low-melting-point alloy powder, samarium oxide powder and samarium-cobalt magnetic powder as raw materials; the component of the samarium cobalt magnetic powder is Sm (Co < 1-a-b-c > Fe Cu Zr < c >) < z >; the component of the low-melting-point alloy is RE1-xMx, RE is one or more of Pr, Nd and Sm, and M is one or more of Cu, Al and Ga. The preparation method comprises the following steps: smelting a samarium-cobalt alloy raw material and a low-melting-point alloy raw material, and sequentially performing coarse crushing, medium crushing and jet milling to obtain samarium-cobalt magnetic powder and low-melting-point alloy powder; mixing samarium oxide powder, low-melting-point alloy powder and samarium cobalt magnetic powder to obtain magnetic powder; sequentially performing magnetic field forming, cold isostatic pressing and low-temperature sintering to obtain a sintered blank; and the sintered blank is sequentially subjected to solution treatment and aging heat treatment. The bending strength and the fracture toughness of the samarium-cobalt magnet are greatly improved, and the samarium-cobalt magnet has high magnetic performance and good mechanical performance.

The application discloses a kind of surface coating low melting point conductive metal's conductive basalt fiber and preparation method thereof, belong to basalt fiber modification technical field.The conductive basalt fiber is made of basalt fiber matrix and the low melting point conductive metal coating combined on its surface by melt impregnation process.The preparation method includes: the pretreatment of defatting, cleaning, drying to basalt fiber matrix;Low melting point conductive metal is melted into homogeneous melt under the protection of inert gas;Through the continuous process of impregnation-drawing-coating-cooling, uniform, dense metal coating is formed on the surface of fiber.The volume resistivity of the fiber obtained by the application is as low as 10 ‑4 ~10 ‑2 Ω·cm, the tensile strength retention rate is greater than or equal to 90%, and the cost is low, the environment is friendly, and it is especially suitable for high-end fields such as electromagnetic shielding, intelligent textiles, etc.

The invention provides sealing glass as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing materials according to a sealing glass formula, uniformly mixing, and carrying out first ball milling; the raw materials are subjected to high-temperature melting, clarification, leakage forming and annealing, and lead glass is obtained; crushing lead glass, performing secondary ball milling, sieving, preparing the obtained glass powder into slurry, coating the surface of the to-be-passivated area with the slurry, and performing heat treatment to form a glass passivation layer; and immersing the glass passivation layer into molten toughening molten salt, and carrying out chemical toughening treatment at a designed temperature to synchronously remove sodium ions, so as to obtain the high-strength low-leakage-current sealing glass. The technical problem to be solved is how to prepare the sealing glass which has higher strength and chemical stability on the basis of meeting the performance that low-melting-point glass can be used for electronic device packaging in the prior art, the strength of the sealing glass can reach 300 MPa or above, the expansion coefficient is 35 * 10 <-6 >-50 * 10 <-6 > / DEG C, and the sealing glass is excellent in insulating property and can be applied to electronic device packaging. And the requirements of development in the fields of semiconductor surface passivation and the like on a sealing glass material can be met.

The invention provides a gradient functional composite material, a preparation method and application of the gradient functional composite material to a die-casting die. The composite material sequentially comprises a bonding layer, a metastable-state high-entropy alloy relaxation layer, a component gradient transition area and a dynamic densification composite surface layer from a base body to the surface. Wherein the relaxation layer can generate reversible martensite phase transformation at the die-casting temperature so as to actively dissipate thermal stress; the composite surface layer contains a low-melting-point nanophase, and can flow at high temperature to realize self-repairing and dynamic lubrication of surface micro-damage. According to the composite material, gradient transition and metallurgical bonding between layers are achieved through continuous process modulation. The coating system provided by the invention has multiple synergistic protection mechanisms of active stress digestion, interface gradient relaxation and surface self-adaptive repair, and can remarkably improve the thermal fatigue resistance, melting loss resistance and demolding performance of the die-casting die, so that the service life of the die is greatly prolonged.