36results about How to "Reduce chance of defects" patented technology

The invention provides a silicon-base compound substrate for preparing a nitride semiconductor epitaxial material, and a manufacturing method of the silicon-base compound substrate. The silicon-base compound substrate comprises a silicon monocrystal substrate, a compound stress covariant layer which is formed on the silicon monocrystal substrate and formed by frequently stacking aluminum nitride and a titanium nitride monocrystal thin film material, and a gallium nitride template layer which is formed on the compound stress covariant layer and consists of a gallium nitride monocrystal thin film material. By the silicon-base compound substrate, the crystal lattice and big heat mismatch problems of the silicon-base gallium nitride material are solved; therefore, the preparation cost of a gallium nitride light emitting diode (LED) epitaxial sheet can be reduced greatly; and the silicon-base compound substrate is suitable for application and market popularization.

The present invention discloses a continuous cast columnar crystal square billet and its columnar crystal control method. It is characterized by that said square billet is continuously cast by using molten steel containing chemical components of screw-thread steel, carbon structure steel, alloy structure steel, spring steel, bearing steel, low-alloy high-strength steel, hard wire steel or cold-short steel. The columnar crystal rate in the central zone of said square billet is 90-100%, and its equiaxed crystal rate is 0-10%. Said invention utilizes forced cooling and thermal stress downwards compression of continuous casting process to raise uniformity of material components, reduce segregation value of material components and internal defect probability and raise columnar crystal rate of square billet, at the same time, said invention adopts forced cooling and high drawing speed so as to make continuous casting machine efficiency be raised by 10%-40%.

The invention belongs to the technical field of low-cost manufacturing of high performance composite materials, and relates to a technical method using a low resin content fiber-reinforced prepreg for preparation of a composite material. First of all, resin content in the prepreg can be regulated by precise control of the concentration of a resin solution in a wet-method prepreg preparing process, and under the premises of ensuring structural integrity and technical operability of the prepreg, fiber tows are partly wetted with resin to obtain the low resin content prepreg; then by combination with a mold-closing RTM (resin transfer molding) technology and in dependence on injection and flowing of low viscosity RTM resin, the reinforced fiber can be finally and completely wetted to obtain the high performance composite material which has good paving technical properties and high fiber collimation degree and fiber volume fraction of both the prepreg and the composite material and can combine manufacturing flexibility of the RTM technology.

The invention relates to a dynamic-temperature-field preparation method for large-size C-axis sapphire crystal. An employed crystal growth furnace heating body comprises an auxiliary heating body at the upper part of the outer side of a crucible, an auxiliary heating body at the outer side and a main heating body at the lower part of the bottom. A tungsten filament of the auxiliary heating body at the upper part of the outer side of the crucible employs a left part and a right part which are in connection in a parallel way. The power of the auxiliary heating bodies and the main heating body are respectively independently controlled by corresponding temperature control systems. By independently controlling the power of the three heating bodies and utilizing the dynamic temperature field method during crystal growth, temperature fields adaptive to demands of expelling bubbles, expanding shoulder and constant-diameter growth of a crystal are formed in the hearth when the crystal grows. In the constant-diameter growth stage, a horizontal growth interface is employed, the crucible wall temperature is close to the melt temperature, and thus no defect is generated caused by impact of a melt convecting to the middle on the crystal growth solid-liquid interface because of high crucible wall temperature. Heat radiation of the crystal is uniform, and thus the center axis does not have too many defects caused by concentrated heat radiation at the center axis. Therefore, the crystal has less defects, and high-quality C-axis sapphire crystal can be grown and obtained.

The invention discloses a preparation method of a silicon epitaxial wafer for a high-voltage power device. According to the method, a reaction cavity of the epitaxial equipment is purified and the content of impurities accumulated in the cavity is reduced by long-time purging of large-flow hydrogen before epitaxial growth; the nonlinear gradient heating is adopted, so that the stress accumulated in the heating stage is released in time, and the generation probability of defects is reduced; and the reaction rate is significantly improved by shortening the distance between a quartz bell jar anda base of the reaction cavity of the epitaxial equipment and adopting a large-flow trichlorosilane and hydrogen proportioning mode, and high-speed epitaxial growth is realized under the premise of ensuring good crystallization quality of the silicon epitaxial wafer. The problem of comprehensive control on thickness, resistivity and crystallization quality in the existing preparation process is overcome by adopting the method of sectional growth of the silicon epitaxial wafer layer. the prepared silicon epitaxial wafer has a bright surface, is free from dislocation, staggered layers, slip linesand fog defects, realizes the controllability of material indexes such as thickness, resistivity and defects and meets the use requirements of the high-voltage power device.

The invention discloses a selective laser melting device. The selective laser melting device comprises a rigid powder laying device, a milling tool cutting device and a control device. The rigid powder laying device comprises a scraping knife mechanism, a guide rail mechanism, a power mechanism and an overcurrent detection mechanism. The power mechanism drives the scraping knife mechanism to movealong the guide rail mechanism. The overcurrent detection mechanism is arranged on the scraping knife mechanism and is connected with the control device. The milling tool cutting device comprises a mechanical arm and a milling tool. The control device is used for receiving and analyzing detection information transmitted by the overcurrent detection mechanism and controls the mechanical arm and themilling tool to realize the high point cutting action according to the detection information. The selective laser melting device conducts forced scraping on high points by means of the rigidity of ascraping knife in the powder laying process. If the high points are cut off by the scraping knife, the powder laying action can be completed smoothly. If the scraping knife gets stuck, cutting of thehigh points is realized through monitoring of the overcurrent detection mechanism and cutting of the milling tool cutting device. It is guaranteed that no high point exist in the manufacturing process. The defect rate of parts is greatly reduced. The precision of the parts is improved.

The invention provides a command scheduling method, device and equipment, and a storage medium. The method comprises the steps of obtaining refreshing times of a storage array; when the refreshing frequency reaches a first preset frequency, generating a temperature state reading request of the storage array, and executing the temperature state reading request; obtaining the current temperature state reading frequency of the storage array; judging whether the temperature state reading frequency reaches a second preset frequency or not; if the temperature state reading frequency reaches the second preset frequency, generating a drift compensation operation request of a data gating signal of the storage array; and in an exclusive arbitration time interval, continuously executing the temperature state reading request or the temperature state reading request and the drift compensation operation request on all the storage arrays, and resetting the temperature state reading times. According to the invention, the number of bit widths of the counter is reduced, hardware resources are saved, and the complexity of the arbiter is reduced.

The invention provides an electromagnetic induction annular heating laser cladding nozzle device and a laser cladding device. The nozzle device comprises a connecting part, an induction coil fixing part, a ceramic inner ring, induction heating coils, an induction heating power supply, a thermocouple and a thermocouple power supply; the induction heating coils are arranged in the induction coil fixing part and is connected to the induction heating power supply; the ceramic inner ring is arranged in the induction coil fixing part, a powder flow channel is formed between the ceramic inner ring and the induction coil fixing part, a thermocouple mounting hole is formed in the ceramic inner ring, and a thermocouple is mounted in the thermocouple mounting hole and connected to the thermocouple power supply; and the connecting part is connected to the ceramic inner ring and the induction coil fixing part, a powder inlet channel communicated with the powder flow channel is formed in the connecting part, and a laser beam channel is formed in the center of the connecting part and the ceramic inner ring. According to the electromagnetic induction annular heating laser cladding nozzle device and the laser cladding device, laser cladding powder is preheated before the powder is converged into a laser beam focus area, and the laser cladding efficiency is improved.

The invention provides a prepreg and a preparation method, the prepreg is composed of continuous reinforced fibers, a thin-layer mesh felt and resin, the prepreg is formed by compounding the continuous reinforced fibers and the thin-layer mesh felt by dipping in a double-sided resin film by a hot melting method, and the thin-layer mesh felt is located at one side of the continuous reinforced fibers, wherein the resin accounts for not more than 15% of the mass of the prepreg, the continuous reinforced fibers account for not less than 80% of the mass of the prepreg, and the balance is the thin-layer mesh felt. Through prepreg structure design and preparation process control, the prepreg meets the requirements of a subsequent slitting process and an RTM forming process, and is convenient to store and transport.

The invention discloses an antioxidant spraying device and an antioxidant spraying process for seamless steel tube production. The spraying device comprises an annular cavity punching machine, a firstpipeline and a second pipeline, wherein the annular cavity punching machine is formed by an ejection rod with an ejection head and a roller, the middle of the ejection rod is conducted, the first pipeline and the second pipeline are arranged in a through hole of the ejection rod, one of the first pipeline and the second pipeline is used as an antioxidant pipeline, the other pipeline is used as acooling water pipeline, an outlet of the antioxidant pipeline is opposite to the inner wall of a hollow capillary, and an outlet of the cooling water pipeline is opposite to the top end of the ejection rod. According to the antioxidant spraying device and the antioxidant spraying process for seamless steel tube production, the inner wall, on which an antioxidant is not sprayed, of the hollow capillary can be prevented from making contact with air, so that the probability of defects of the inner wall of the hollow capillary is reduced, the surface quality of the inner wall of a steel tube is increased, special stations for spraying the antioxidant are reduced, and the production rhythm is increased.

The invention discloses an electronic component pin regulating device. When the electronic component pin regulating device is used for assembling an electronic component onto a circuit board, connecting pins of the electronic component are regulated and fixed so as to be connected with multiple connecting points on the circuit board in para-position mode. The electronic component pin regulating device comprises an insulating body and multiple channels, wherein the channels penetrate through the insulating body, each channel is provided with an inlet end and an outlet end respectively, the inlet ends correspond to the positions of the connecting pins on the electronic component, the outlet end correspond to the positions of the connecting points, and the connecting pins are regulated and fixed through the channels. Therefore, the electronic component pin regulating device can enable the connecting pins to be quickly and rightly connected with the multiple connecting points in para-position mode, further can enable the time required by procedures for installing the electronic component on the circuit board to be remarkably decreased, and facilitates manual operation.

The invention discloses a method for improving the quality of a casting blank. The method comprises the following steps that the cooling water flow of a crystallizer is adjusted to 130 m<3>/h-140 m<3>/h; (2), according to the atomization effect, the nozzle model of each section is selected, wherein the nozzle model of a foot roller section is 3/8PZ10067QZ5, the nozzle model of a section I of a spraying section is 3/8PZ4565QZ2, the nozzle model of a section II of the spraying section is HPZ2.5-65QZ2, and the nozzle section of a section III of the spraying section is HPZ2.5-65QZ2; (3), the casting speed of 70# and 82B high-carbon steel is set to be 1.75+/-0.02 m/min; (4), electromagnetic stirring parameters of the crystallizer of the 70# and 82B high-carbon steel are set as follows that the current is 320 A, the frequency is 3.5 Hz, and the specific water flow is 0.78 L/kg; and (5), secondary cooling water distribution is conducted, specifically, section III water supply is closed, section II water is reduced to 5 m<3>/h-6 m<3>/h, and section I water is reduced to 10 m<3>/h-11 m<3>/h. According to the method, after processes such as casting machine secondary cooling nozzles, electric stirring parameters and water distribution are optimized, internal cracks and center segregation defects are effectively controlled, and the internal quality of the casting blank is further improved.