8results about How to "Uniform grain" patented technology

This invention discloses a method for preparing high-elongation bars for cold forging, belonging to the field of aluminum alloy preparation technology. Through optimization of composition and process, the prepared bars possess high purity, uniform and fine equiaxed grain structure, and excellent plasticity, with significantly improved elongation. This meets the stringent requirements of cold forging for high material plasticity, resulting in a bright, crack-free surface and uniform grains after cold forging, overcoming problems such as oxide scale, coarse grains, and poor dimensional accuracy caused by hot forging. Furthermore, the introduction of modified talc and sodium nitrate as refining agents further promotes uniform microstructure, achieving high elongation and excellent cold forging performance.

This invention discloses a high-performance corrosion-resistant non-magnetic stainless steel and its preparation method, belonging to the technical field of stainless steel materials. It solves the problems of existing non-magnetic stainless steels where the mechanical properties and corrosion resistance cannot be simultaneously and effectively improved, and the microstructure uniformity is poor. The high-performance corrosion-resistant non-magnetic stainless steel comprises, by mass percentage: 18.30% ≤ Cr < 21.00%, 2.60% ≤ Mo ≤ 3.00%, 4.10% ≤ Ni ≤ 4.50%, 20.50% < Mn ≤ 22.00%, Si ≤ 0.4%, 0.015% < Nb ≤ 0.03%, P ≤ 0.025%, S ≤ 0.01%, C ≤ 0.02%, 0.80% < N ≤ 0.85%, with the balance being Fe and other unavoidable impurities. The high-performance corrosion-resistant non-magnetic stainless steel of this invention has fine and uniform grains, and excellent mechanical properties and stress corrosion resistance.

This invention discloses a stress corrosion resistant non-magnetic stainless steel and its preparation method, belonging to the technical field of stainless steel materials. It solves one of the problems in existing technologies: the microstructure uniformity of non-magnetic stainless steel is difficult to control, and the mechanical properties and stress corrosion resistance of existing non-magnetic stainless steel cannot be simultaneously and effectively improved. The composition of the stress corrosion resistant non-magnetic stainless steel, by mass percentage, includes: 18.30% ≤ Cr < 21.00%, 1.10% ≤ Mo ≤ 1.40%, 2.60% ≤ Ni ≤ 3.0%, 20.50% < Mn ≤ 22.00%, Si ≤ 0.4%, 0.01% ≤ Nb ≤ 0.015%, P ≤ 0.025%, S ≤ 0.01%, C ≤ 0.02%, 0.76% ≤ N ≤ 0.80%, with the balance being Fe and other unavoidable impurities. The stress corrosion resistant non-magnetic stainless steel of this invention has fine and uniform grains, and excellent mechanical properties and stress corrosion resistance.

This invention discloses a method for hydrolyzing high-F-value titanium liquid, as well as the hydrolyzed material and titanium dioxide, comprising the following steps: S1. Preparing the hydrolyzed titanium liquid and heating it; preparing seed crystal preparation titanium liquid and alkaline solution; S2. When the hydrolyzed titanium liquid reaches 80-85℃, heating the seed crystal preparation titanium liquid and the alkaline solution to 50-60℃ respectively; S3. Adding the seed crystal preparation titanium liquid to the alkaline solution, heating to 92-95℃, and maintaining the temperature until the final stability of the hydrolyzed seed crystals is 90-100ml, at which point the preparation of the hydrolyzed seed crystals is complete; S4. Stopping the heating when the temperature of the hydrolyzed titanium liquid reaches 92-95℃, adding the prepared hydrolyzed seed crystals, and stirring; S5. Heating the hydrolyzed titanium liquid to boiling, maintaining a gentle boil, and when the hydrolyzed titanium liquid turns white, adding dilution water until the hydrolysis is complete. The prepared hydrolyzed seed crystals have uniform grain size, the hydrolyzed material has uniform particle size, the hydrolysis quality of the high-F-value hydrolyzed titanium liquid is high, and the water washing time is short.

The application discloses a semi-solid thixotropic die casting forming method of a narrow solid-liquid two-phase zone alloy, and comprises the following steps: step one: the narrow solid-liquid two-phase zone alloy is added into a heating device and heated to a superheating temperature, and after complete melting, the alloy is cooled for a certain time to obtain an alloy blank with a cast structure; step two: the alloy blank is added into an extrusion device to complete cold extrusion, and an alloy blank containing high-density dislocations and lattice distortion structures is obtained; step three: the alloy blank is heated for the first time, the heating temperature is set between a recrystallization temperature and a solidus temperature of the alloy, and isothermal heat treatment is carried out to obtain fine and uniform recrystallized grains; step four: the alloy blank is heated for the second time, the temperature is set above the solidus temperature of the narrow solid-liquid two-phase zone alloy, and isothermal heat treatment is carried out to obtain a semi-solid blank; and step five: the semi-solid blank is subjected to die casting forming. The application has the advantages that excellent castings with physical properties are formed.

The application discloses a preparation process of a lead zirconate titanate (PZT) film layer, a film layer structure and application thereof, and relates to the technical field of piezoelectric material film layer preparation. The preparation process comprises the following steps: S1, forming a low tensile stress silicon nitride layer on the surface of a substrate, which is used for homogenizing the in-plane stress gradient of a wafer; and S2, forming a piezoelectric functional layer on the surface of the silicon nitride layer in a sputtering mode, wherein the piezoelectric thin film material of the piezoelectric functional layer is lead zirconate titanate (PZT). The film layer structure and the preparation process thereof adopt the silicon nitride layer to relieve the thermal mismatch stress of the piezoelectric functional layer system, can improve the piezoelectric constant e31 of the central region of the wafer, and improve the uniformity of the whole wafer.

This invention discloses a high-performance corrosion-resistant non-magnetic drill collar and its manufacturing method, belonging to the field of stainless steel material technology. It solves the problems of poor microstructure uniformity and the inability to simultaneously and effectively improve mechanical properties and stress corrosion resistance in existing non-magnetic drill collars. The manufacturing method includes: melting steel; preparing ingots; forging the ingots into steel billets using a high-speed forging mill after they are removed from the furnace; heating and holding the steel billets; forging the steel billets into intermediate billets using a radial forging mill; water-cooling the intermediate billets; performing secondary forging of the water-cooled intermediate billets using a radial forging mill, followed by air cooling to obtain finished steel billets; straightening, drilling, reaming, boring, internal controlled rolling, and shot peening of the finished steel billets to obtain the high-performance corrosion-resistant non-magnetic drill collar. The high-performance corrosion-resistant non-magnetic drill collar of this invention has fine and uniform grains and excellent mechanical and corrosion resistance.

This invention relates to an explosive granulation device, comprising a reciprocating arm (1), a screen (2), a grinding wheel (3), and an adjusting component (4); the reciprocating arm (1) comprises a symmetrically arranged left arm and a right arm, which reciprocate up and down in opposite directions around the center point where they connect; the two ends of the strip screen (2) are respectively fixed on the left and right arms of the reciprocating arm (1), forming a V-shaped structure; the grinding wheel (3) is disposed on the inner surface of the V-shape of the strip screen (2), and a spindle (7) is disposed on the axis of the grinding wheel (3); the adjusting component (4) is connected to both ends of the spindle (7) of the grinding wheel (3) and is used to adjust the contact pressure between the grinding wheel (3) and the surface of the strip screen (2). This invention has a simple structure, is easy to form a continuous production line with upstream and downstream equipment, is easy to control, and has high reliability; it occupies little space, has a wider range of product size applicability, good safety, and is convenient to maintain.