32results about How to "Improve thermal cycle life" patented technology

A reduction in tube to header joint failures in a heat exchanger having spaced headers (12,14), elongated, side-by-side parallel spaced tube slots (22) in the headers (12,14) along the length thereof and a plurality of flattened tubes (26) having ends (24) received in the tube slots (22) and metallurgically bonded to the header (12,14) thereat was achieved through the use of a reinforcing structure (38) having at least two projections (40) having a cross sectional shape complimentary to at least a part of the surface of the tubes (26) at their ends (24) and a length sufficient to extend along the tube ends (24) to a location past the metallurgical bonds between the tube ends (24) and a header (12,14), and a spine (44) extending transverse to the projection. Also disclosed is a reinforcing structure (38) and a method of reinforcing the tube to header joints in a heat exchanger.

The invention discloses a pyrochlore structural rare-earth zirconate material system capable of being used for a heat barrier coating. The chemical composition of the material is (0.5-x)R'2O3-0.5Sm2O3-xR''2O3-2ZrO2, wherein x is more than 0 and less than or equal to 0.25; the R' is rare-earth elements or composition thereof, the ion radius of which is greater than that of Sm; and R'' is rare-earth elements or composition thereof, the ion radius of which is smaller than that of Sm. The material provided by the invention has low thermal conductivity, high thermal stability and high-temperature sintering resistance; the thermal expansion performance of the material is stable compared with a single pyrochlore structural material; and the material is favorable for reducing thermal stress generated by mismatching of thermal expansion coefficients in the thermal cycle process, and can prolong the thermal cycle life of the coating. Because of good high-temperature phase stability, the pyrochlore structural rare-earth zirconate material can be used for designing and preparing a novel high-temperature heat barrier coating material, the use temperature of which is below 1,550 DEG C.

The invention belongs to the field of thermal spraying, and relates to a high-temperature oxidation resistant coating on a niobium alloy surface and a preparation method of the high-temperature oxidation resistant coating. The coating is in a dual-layer structure with a bottom coating Mo1-xWx(Si1-y-zAlyBz)2 and a surface coating Mo1-xWx(Si1-y-zAlyBz)2-(10-20)%wt HfSi2, and prepared on a niobium alloy matrix surface by a high-energy plasma spraying process, wherein a bottom coating powder material Mo1-xWx(Si1-y-zAlyBz)2 is prepared by a self-propagating process, and the spherical particles meeting the requirements of the spraying process are obtained by applying a plasma spheroidizing process; surface coating powder materials Mo1-xWx(Si1-y-zAlyBz)2 and HfSi2 are mixed evenly in a mechanical mixing manner. The coating has excellent high-temperature oxidation resistance at 1500-1800 DEG C, and can be applied to high-temperature protection of niobium alloy parts.

The invention relates to a series of ceramic materials used as high temperature thermal barrier coating materials and their use, wherein the chemical constitution of the ceramic material being A2ZrxCe(1-x)2O7, wherein 0<=x<=0.9, an is one or combination of two of Nd, Sm, Eu, Gd and Tb. The ceramic material has high coefficient of thermal expansion, thus can be designed into thermal barrier coating material, whose application temperature interval is between room temperature to 1400 deg. C.

The invention discloses a preparation method of a CMAS corrosion-resistance micronanometer composite thermal barrier coating layer. The thermal barrier coating layer includes a bonding layer prepared on an alloy basal body, a first ceramic layer and a second ceramic layer; the first ceramic layer is a yttrium oxide part stable zirconium oxide coating layer, can be prepared by atmosphere plasma spraying, an electronic beam physical vapor deposition method or a plasma evaporation deposition method, and has a thickness of 50-200 microns; and the second ceramic layer is a CMAS-resistance coating layer prepared by a plasma evaporation deposition system, and has a thickness of 1-100 microns. At high temperature, molten CMAS is not wet on the surface of the prepared second ceramic layer. The prepared multi-layer thermal barrier coating layer system including the bonding layer, the first ceramic layer and the CMAS-resistance second ceramic layer can effectively stop permeation of molten CMAS, and is excellent in molten CMAS corrosion resistance.

The present invention provides a 3D printing packaging method of a flip chip. The method is characterized by comprising the following steps of S1 utilizing a computer to design a three-dimensional digital model of an LED device, programming the LED device, after the hierarchical slicing processing, introducing a 3D printer, and utilizing the computer to control the hierarchical printing; S2 utilizing a suction nozzle to absorb the flip chip, and fixing under a reflector cup; S3 carrying out the 3D printing on a solder layer and a radiating substrate, wherein the radiating substrate is equipped with a leading-out circuit in electrode connection with the chip, and further can comprises a step S4 of filling the fluorescent powder. Relative to the general packaging, according to the present invention, the die bonding wires and the eutectic solders are not needed, the packaging yield is improved, a support and a PCB or a COB do not need to purchase, the packaging cost is reduced, the packaging research and development cycle is shortened, and the packaging appearance diversity is increased, and the LED thinning and miniaturization are promoted.

The invention discloses a nano insulating coating which is prepared from the following raw materials in parts by weight: 100 parts of an organosiloxane modified acrylic emulsion, 5-12 parts of a silicon dioxide aerogel, 1-2.6 parts of ceramic fibers, 1-2.5 parts of a carbon nano tube, 0.2-1 part of calcium silicate, 2-5 parts of nano zirconium oxide, 3-7 parts of nano zinc oxide, 5-9 parts of calcium carbonate whiskers, 15-20 parts of sepiolite, 5-20 parts of expanded perlite, 8-15 parts of nano titanium dioxide, 0.8-2.0 parts of a segmented copolymer, 1.5-3.8 parts of dodecanol ester, 0.2-5.0 parts of benzotriazole, 2-3.5 parts of a defoaming agent, 0.5-2 parts of glycerol, 0-1.5 parts of a thickener, 3-10 parts of a coupling agent and 30-60 parts of water. The nano insulating coating disclosed by the invention is good in insulation, high-temperature resistant, high in strength and pollution resistant and is strong in adhesive force and long in service life of building wall spaces and base bodies.

The invention discloses a low-temperature lead-free solder paste and a preparation method thereof. The low-temperature lead-free solder paste is composed of the following raw materials in mass percent: low-temperature tin-bismuth-silver-copper quaternary lead-free solder powder 86% to 91%; flux 9 %~14%; wherein, the low-temperature tin-bismuth-silver-copper quaternary lead-free solder powder is composed of four elements: tin-bismuth-silver-copper, wherein the mass percentage of bismuth is 46-52%, and the mass percentage of copper 0.3-1.2%, the mass percentage composition of silver is 0.4-1.2%, and the mass percentage composition of tin is 45.6-53.3%; Adopt the solder paste that the present invention makes, its bismuth content is relatively high but the range is reasonable, can The solidus temperature of the product is increased from 138°C to 151°C, which is suitable for low-temperature packaging technology, and the peak soldering temperature does not exceed 200°C. Compared with the Sn42Bi58 alloy, this product has better tensile strength, shear strength, drop resistance and thermal cycle Life expectancy has been greatly improved.

The application provides a particle used for a thermal barrier coating, a preparation method thereof, a thermal barrier coating and an engine, and relates to the field of new materials. Particles used for thermal barrier coatings, including shells and cores; the porosity of the surface of the shells is less than or equal to 5%; the cores have first closed cells with a pore size of 1-5 μm, and the first closed cells There are first skeleton microparticles in between, and the particle diameter of the first skeleton microparticles is 0.1-2 μm. Thermal barrier coatings, obtained by plasma jet deposition using particulate matter for thermal barrier coatings. Engines, including thermal barrier coatings. The particles used in the thermal barrier coating and the thermal barrier coating provided by the present application have good performance of high temperature thermal cycle resistance.

The invention relates to a preparation method of a thermal barrier coating with an interlayer pore structure, which comprises La 2 o 3 , CeO 2 , ZrO 2 The powder is heat-treated; the heat-treated powder is mixed with a dispersant in proportion, and deionized water is added for ball milling to obtain a slurry; La 2 o 3 , CeO 2 , ZrO 2 The molar ratio between the powders is 0.5:(1-x):x, wherein 0≤x≤0.8; the slurry after ball milling is dried and heat-treated to form a phase to obtain a phase-forming powder; the phase-forming powder is mixed with deionized water and dispersed The mixture is ball-milled to obtain a suspension; the suspension is used as a raw material, and the suspension plasma spraying method is used to spray on the base material. The present invention adopts the La prepared by the suspension plasma spraying method 2 (Ce 1‑x Zr x ) 2 o 7 The coating has excellent high-temperature phase stability, and the prepared coating has a uniform interlayer pore structure, which is conducive to reducing the thermal conductivity of the coating and improving the thermal cycle life of the coating.

The invention discloses a thermal barrier coating layer with a particle scouring resistant surface layer and a preparation method thereof. The thermal barrier coating layer is a ceramic layer with a feather structure and arranged on a basal body by adopting a plasma spraying-physical vapor deposition process; the upper end part of the ceramic layer is a high-cohesion-strength surface layer; the part, below the high-cohesion-strength surface layer, of the ceramic layer is in no-interface connection with the high-cohesion-strength surface layer; and the high-cohesion-strength surface layer has the same material components, object phases and macroscopic feather structures with the ceramic layer below the surface layer. The thermal barrier coating layer is simple in process, low in cost and high in coating bonding strength; and the prepared thermal barrier coating layer with the high-cohesion-strength surface layer can greatly improve the particle scouring resistance, and is long in service life.