39results about How to "Reduce the incidence of cracks" patented technology

Technology of making freestanding gallium nitride (GaN) wafers has been matured at length. Gallium nitride is rigid but fragile. Chamfering of a periphery of a GaN wafer is difficult. At present edges are chamfered by a rotary whetstone of gross granules with weak pressure. Minimum roughness of the chamfered edges is still about Ra 10 μm to Ra 6 μm. The large edge roughness causes scratches, cracks, splits or breaks in transferring process or wafer process. A wafer of the present invention is bevelled by fixing the wafer to a chuck of a rotor, bringing an edge of the wafer into contact with an elastic whetting material having a soft matrix and granules implanted on the soft matrix, rotating the wafer and feeding the whetting material. Favorably, several times of chamfering edges by changing the whetting materials of smaller granules are given to the wafer. The chamfering can realize small roughness of Ra 10 nm and Ra 5 μm at edges of wafers.

The invention discloses a SCR (Selective Catalytic Reduction) honeycomb type denitration catalyst and a preparation method thereof, and belongs to the technical field of SCR catalysts. The SCR honeycomb type denitration catalyst is prepared from raw materials comprising the following ingredients: titanium dioxide, carboxymethylcellulose, polyoxyethylene, fiber, deionized water, ammonium metavanadate, ammonium metatungstate, ammonium hydroxide, lactic acid, cerous nitrate hexahydrate and praseodymium nitrate hexahydrate, wherein a relationship between the diameter R of the fiber and the averagegranularity d50 of the titanium dioxide is that R is equal to 3-8 d50, a relationship between the fiber length L under the diameter R and the granularity d of the titanium dioxide is that L is equalto 5000-6000 d, and the value range of d is d10-d90; a ratio of the adding mass m1 of the fiber to the adding mass m2 of the titanium dioxide is that m1:m2 is equal to (0.06 to 0.15):1. The crack generation rate in a drying process of the SCR honeycomb type denitration catalyst prepared after the optimal selection of the fiber can be obviously lowered, and the mechanical strength of a finished product is obviously improved.

The invention provides a preparation method of an annular sintered neodymium-iron-boron magnet and a forming die of the annular sintered neodymium-iron-boron magnet. The forming die comprises a main body part, an upper pressing head, a lower pressing head and a die cavity; the main body part comprises two opposite non-magnetic-conductive side plates and two opposite magnetic-conductive side plates; in a space formed between the two non-magnetic-conductive side plates and the two magnetic-conductive side plates, the lower pressing head is located at the bottom of the space, and the upper pressing head is located at the top of the space. The die cavity is located between the upper pressing head and the lower pressing head, the flexible cylindrical core is placed in the die cavity, the flexible cylindrical core is placed in the die cavity after the neodymium iron boron magnetic powder in a loose state is placed in the die cavity during preparation, and a magnet finished product is obtained through pressing of a forming die. The method and the device with the mold core structure have the advantages that the material utilization rate and the product percent of pass can be greatly improved when the method and the device with the mold core structure are used for producing the annular sintered neodymium-iron-boron.

The invention discloses a method for adjusting the secondary cooling water amount and the roll gap value of a double-flow slab casting machine. In the double-flow slab casting machine, 12 cooling regions are formed for secondary cooling; 10 cooling water meters are provided; five grades, i.e., strong cooling: the secondary cooling water amount is 1.0-1.1 L / kg, medium cooling: the secondary cooling water amount is 0.8-0.9 L / kg, weak cooling: the secondary cooling water amount is 0.7-0.8 L / kg, medium-weak cooling: the secondary cooling water amount is 0.45-0.6 L / kg, and slight cooling: the secondary cooling water amount is 0.4-0.45 L / kg are divided to adapt to the cooling requirements of different types of steel respectively; the roll gap of a secondary cooling region support roll is consistent with the linear shrinkage rule of a casting blank from top to bottom, and decrease continually; and the roll opening between the outlet of a previous fan-shaped section and the inlet of a next fan-shaped section is kept consistent. By adopting the method, the internal cracking rate is lowered, the macrostructure of the casting blank is optimized, and the performance yield of steel is increased.

A welding method of a sealed storage battery provided with a case configured to encapsulate electrodes and electrolyte therein; a cover configured to cover the case; and two terminals inserted into into a hole provided in the cover body, connected to a pair of electrodes, and formed of a material of a composition different from the lead material, the soldering method comprising: squeezing and extending each of the two terminals along the cover body the distal end side of the terminal, and along the boundary line between the peripheral edge of the distal end side of the terminal and the cover body and alternately and repeatedly pass through the position on the terminal side of the boundary line regarded as the reference line and the cover body side of the boundary line continuous welding at the position on the

The invention relates to the technical field of steel and iron smelting, in particular to a continuous casting method of a high-carbon steel plate blank. The method comprises the following steps: the casting superheat degree of the high-carbon steel plate blank is controlled within 10-20 DEG C by low superheat degree; the low-pulling-speed continuous casting is performed for the high-carbon steel plate blank, and the pulling speed is controlled within 0.9-1.1 m / min; the aerial fog cooling is performed for the high-carbon steel plate blank; the taper of a crystallizer is controlled according to variable taper, wherein the alkalinity of covering slag in the crystallizer is controlled within 0.93-0.99; the melting point of the covering slag is not higher than 1050 DEG C; and the viscosity of the covering slag is not higher than 0.140 pa.s. The method reduces the large surface and angle stress, enhances the solidification uniformity of a blank shell, reduces the surface crack generation rate of the plate blank, and improves the center segregation level.

The invention relates to a withdrawal and straightening force fault diagnosis method of a sector segment of a continuous casting machine. The withdrawal and straightening force fault diagnosis method includes the steps that an equipment state parameter database of a withdrawal and straightening machine is set up; a withdrawal speed curve, a total withdrawing and straightening curve, a flow casting tracing curve and a hidden danger segment withdrawing and straightening curve are drawn respectively according to measured data. If first total withdrawal and straightening force and second total withdrawal and straightening force do not exceed the range of the corresponding total withdrawal and straightening force in the database, hidden danger does not exist, and diagnosis is over; and otherwise, existence of the hidden danger is confirmed and the next step is executed; stressed abnormal points are determined, and the stressed abnormal points are verified. With the adoption of the withdrawal and straightening force fault diagnosis method of the sector segment of the continuous casting machine, under the same working rate of the casting machine, due to the fact that the hidden danger existing in the sector segment can be found in advance, the stressed condition of a casting blank is greatly improved, the quality of the casting blank is greatly improved, the crack occurrence rate of crack-sensitive steel is lowered to 3.5%, the commuted amount is effectively reduced, and the fault time is effectively shortened. The withdrawal and straightening force fault diagnosis method of the sector segment of the continuous casting machine is simple in operation, high in sensitivity, timely in detection and precise in positioning.

The invention discloses a tinplate base material used for a low-defect-rate bottle cap and a reduction production technology and belongs to the technical field of steel making and steel rolling. The control range of chemical components of the bottle cap steel base material include, by weight percent, 0.05%-0.08% of C, 0.60%-0.75% of Mn, smaller than or equal to 0.015% of Si, smaller than or equal to 0.020% of S, smaller than or equal to 0.020% of P, 0.025%-0.040% of Al, smaller than or equal to 0.008% of As, smaller than or equal to 0.003% of N, smaller than or equal to 0.003% of O and the balance iron and inevitable impurities. A continuous casting peritectic area is avoided by limiting the control range of the carbon chemical components, the defect of solution strengthening caused by carbon drop is overcome by improving the carbon control target, after-furnace slag washing and large-air-capacity argon blowing are used for replacing vacuum refining to ensure steel cleanliness, and a chamfer crystallizer and specific protection slag are adopted for ensuring the surface quality of a casting blank. An RH vacuum refining technology is omitted, and better finished product edge portion quality is improved.

The present disclosure provides a flexible display panel and a display device. The flexible display panel includes a flexible substrate and a backplane disposed on the back of the flexible substrate. The backplane includes a bending area and a A non-bending area, wherein the bending area includes a plurality of first bending areas and a plurality of second bending areas, and a plurality of the first bending areas and a plurality of the second bending areas are alternately arranged, And the hardness of the first bending area is greater than the hardness of the second bending area, ensuring that the bending area of ​​the back plate has a certain hardness to support the flexible display panel, while the second The material of the bending area is an elastic material, which effectively relieves the stress concentration, thereby reducing the occurrence rate of cracks on the flexible display panel, and improving the service life and performance of the flexible display panel.