57results about How to "Large residual stress" patented technology

A multilayer ceramic capacitor having a high dielectric constant, a large capacitance and a high reliability can be obtained by controlling a value of residual stress in it.

This invention discloses a method for laser local bonding of silicon / glass. The method comprises: washing, performing a first activation, performing a second activation, pre-bonding, and laser heating. After surface activation treatment, glass and silicon wafer can be intimately bonded by laser local bonding without the need for outside force. The method realizes laser local bonding through local high temperature in a certain region, and has a high bonding strength. As a whole, the silicon wafer has a low temperature, and does not have unnecessary temperature gradient or stress field distribution. Thus, the properties of the integrated pressure or temperature sensor are not influenced. The method has such advantages as simple apparatus, easy local temperature control, and high bonding efficiency.

The invention discloses a method for eliminating re-crystallization tendency of a laser 3D printed single-crystal high-temperature alloy, belonging to the field of manufacturing of laser additives and preparation of the single-crystal high-temperature alloy. By utilizing laser 3D printing as a production technology, the epitaxial growth of the laser-formed dendritic structure on a single-crystal high-temperature alloy base material can be realized through controlling technological parameters. In addition, the temperature field of the printing process is controlled so that the residual stress of the 3D printed single-crystal high-temperature alloy parts is at a lower level, and the re-crystallization tendency of the laser 3D printed single-crystal high-temperature alloy is thoroughly eliminated. The method can be used for preparing large-size single-crystal high-temperature alloy without re-crystallization tendency, and single-crystal high-temperature alloy blades can be prepared by using laser 3D printing on the basis.

A seal structure includes a thick abradable film, thereby improving sealing performance. A seal structure (1) is provided with at least one fin (5) that projects in a ring-shape from a circumferential surface of a rotating shaft (3) and that is provided along an axial direction (L) and a seal member (9) having a ring-shaped sealing surface (19) opposed to the fin (5), and on which an abradable layer (25) is formed by thermally spraying abradable material onto the sealing surface (19), the seal structure (1) is provided with tapered portions (21) inclined in a radial direction (K) at end portions of the sealing surface (19) in the axial direction (L).

The invention provides a metal material surface strengthening method based on the mixed surface nanocrystallization technology. The method comprises the steps that the surface of a metal material sample is ground and polished; supersonic speed microparticle bombardment surface nanocrystallization treatment is carried out, a nanometer layer with the thickness not smaller than 50 micrometers is formed on the surface of the base material to be welded, the average size of surface nanometer crystals is not larger than 50 nm, the surface roughness is larger than 3 micrometers, and the surface microhardness is larger than 250 HV; and the surface of the metal material sample is subjected to surface mechanical rolling. By means of the method, the surface roughness of the surface-nanocrystallized metal material can be greatly improved.

The invention aims to improve not only the resistance to abrasion and scoring, but also the fatigue strength against pitting and chipping, without increasing the number of steps of the manufacturing process.The tooth face 2 of the gear is smoothed by gyro polishing. In the thus smoothed tooth face 2, a multitude of microscopic recesses 3 are randomly formed by liquid honing in which microscopic hard particles are collided with the tooth surface together with liquid. By the liquid honing, a large compressive residual stress is produced on the tooth face 2. This improves not only the resistance to abrasion and scoring, but also the fatigue strength against pitting and chipping, without increasing the number of steps of the manufacturing process.

The invention belongs to the field of surface coating processing, and particularly discloses an ultrahigh-speed laser-induction composite cladding method and device. Aiming at a workpiece to be cladded as a processing object, the ultrahigh-speed laser-induction composite cladding device is provided with an induction heating coil used for realizing the fact of preheating the workpiece, the induction heating coil is arranged nearby the workpiece to be cladded, a area to be cladded of the workpiece is heated to a set temperature through the shape of the induction heating coil and the spatial arrangement of the induction heating coil relative to the workpiece to be cladded; and carrying out ultrahigh-speed laser-induction composite cladding above the area to be cladded of the workpiece by adopting ultrahigh-speed laser cladding and induction heating modes, so that interaction effect between a laser beam spot and a powder beam flow is carried out at a target position of a cladding area to heat a alloy powder to a molten drop or semi-molten drop state, and the alloy powder is sprayed to a micro molten pool on the preheated surface of the workpiece in a liquid or semi-solid form so as toprepare a required cladding layer. By means of the ultrahigh-speed laser-induction composite cladding method and device, high-precision, high-performance and metallurgical-defect-free ultra-efficientdeposition of the metal cladding layers of various materials can be achieved on the surface of a metal component.

A bearing component formed from a bearing steel, wherein the component has an outer surface and comprises through-hardened bainite and / or martensite and has a substantially homogeneous chemical composition, at least a part of the bearing component having a compressive residual stress profile comprising −25 to −1000 MPa at the near surface, wherein the near surface is defined as a region 500 microns or less below the outer surface.

The invention relates to a manufacture method of a mesh-like transparent electrode, which is characterized by the following steps of: firstly, depositing a GaN material in an epitaxial growth process of an LED (Light-Emitting Diode); secondly, depositing a transparent electrode layer after the LED epitaxial growth; and finally, manufacturing the deposited transparent electrode layer to be a mesh-like layer. The mesh-like transparent electrode layer with a high dielectric constant is used as a current expansion layer and a stress buffering layer; therefore, the luminous efficiency is improved and the reliability of the device is further improved simultaneously. And more importantly, the invention can remove the larger residual stress existing inside an LED epitaxial wafer in the future, thereby preventing an LED protection layer from releasing and improving the entire quality of the LED.

The invention provides an alumina ceramic-wear resistant steel composite material which comprises a wear resistant steel matrix, a ceramic layer and an enamel layer; and the enamel layer is arranged between the wear resistant steel matrix and the ceramic layer. The invention also provides a preparation method of the alumina ceramic-wear resistant steel composite material. The preparation method comprises the following steps of performing decarburization treatment on the wear resistant steel matrix to obtain the wear resistant steel matrix, preparing enamel powder and ceramic particle, then sequentially putting the materials in a lapping tool, and performing bi-directional compression and normal pressure sintering to obtain the alumina ceramic-wear resistant steel composite material. For the alumina ceramic-wear resistant steel composite material provided by the invention, the enamel layer can wet the ceramic layer and can improve the wettability with the wear resistant steel matrix toform chemical bond bonding; a part of the enamel powder is charged in pores of the ceramic layer, so that bubbles are difficultly formed between the wear resistant steel matrix and the enamel layer; and TiO2-x and CuO in the ceramic layer can lower the sintering temperature as sintering aids, prevent the wear resistant steel matrix from oxidizing, improves the preparation efficiency and lowers thepreparation cost.

The invention provides a method for conducting magnetron sputtering on the surface of an Al2O3 ceramic matrix to coat the Al2O3 ceramic matrix with a nanometer copper film. According to the method, byconducting magnetron sputtering to coat the Al2O3 ceramic matrix with the nanometer copper film, protection of the film for the matrix is better, and good electrical conductivity and film-matrix adhesion are achieved; and the produced coat (film) is dense and flat, the hardness is high, the wear resistance is good, a wear rate decreases, and the high-temperature oxidation resistance is enhanced,so that the microstructure of the material (Al2O3 ceramic matrix) is improved, the comprehensive performance of the material (Al2O3 ceramic matrix) is improved, and meanwhile, the film has a good electrical property.