5results about How to "Avoid grain growth" patented technology

This invention discloses a low-alloy medical-grade heterogeneous magnesium alloy, its preparation method, and its applications. The preparation method includes: melting a magnesium matrix under a protective atmosphere to obtain a melt; maintaining a constant temperature and under stirring conditions, adding an alloying element to the melt for smelting to obtain an alloy melt; lowering the temperature of the alloy melt, removing slag to obtain a melt to be cast, then casting it into a mold and air-cooling it to obtain an alloy ingot; holding the alloy ingot in an oxygen-free environment and water-quenching it to obtain a solid solution alloy billet; removing the oxide layer from the surface of the solid solution alloy billet, preheating it at 330~380℃ for 1~1.5h, and then hot-extruded it at 330~380℃, followed by air cooling to obtain a low-alloy medical-grade heterogeneous magnesium alloy. This invention introduces an alloying element into the magnesium matrix and further optimizes the hot extrusion temperature and extrusion ratio to obtain a low-alloy medical-grade heterogeneous magnesium alloy with a heterogeneous structure.

This invention provides a rare-earth-doped potassium sodium niobate transparent ceramic, its preparation method, and its application. Its chemical composition is: (K 0.5 Na 0.5 ) （1‑x‑y） Eu x Y y Nb （1‑z） Ta z O3, where 0 < x < 0.1, 0 < y < 0.01, 0 < z < 0.02. The rare-earth-doped potassium sodium niobate transparent ceramic of the present invention exhibits high light transmittance and light-changing properties; with the introduction of Y and Ta, the crystal structure and microstructure of the material are changed, increasing the vacancy-related defects of the material, while inhibiting the grain growth of the material, thereby simultaneously improving the light transmittance and light-changing rate of the ceramic. Its light transmittance can reach more than 70%, and the light-changing rate can reach up to 37.58%.

This application discloses a post-processing technology and apparatus for ViGa gas atomization powder production. The process employs a four-step synergistic treatment: graded pre-separation, plasma desorption, vibration densification, and cooling shaping. First, a three-stage airflow classifier removes free fine powder. Then, radio frequency plasma bombardment desorbs attached satellite spheres and melts irregular protrusions on the powder surface. The powder is then densified and residual satellite spheres are removed via an ultrasonically vibrating fluidized bed. Finally, rapid cooling with inert gas shapes and fixes the spherical morphology. The apparatus integrates a feeding system, a grading module, a plasma module, a vibration module, a cooling module, and a control system, enabling precise control of process parameters. This application reduces the satellite sphere content in the powder to below 5%, increases sphericity to above 0.95, achieves a Hall flow rate ≤25s / 50g, a powder deformation rate <2%, and a single-batch energy consumption <200kW·h / ton. It is compatible with various ViGa gas atomization powders and solves the problems existing in the prior art.

The application discloses a high beryllium copper alloy strip based on electric pulse assisted rolling and a preparation method thereof, and belongs to the technical field of precipitation hardening alloy material processing. The preparation method comprises the following steps: S1, after preparing materials according to the mass percentages of various chemical components of the beryllium copper alloy to be prepared, the materials are put into a vacuum induction melting furnace to be vacuum melted into a liquid state, and then the liquid state is poured into a beryllium copper alloy ingot; S2, the beryllium copper alloy ingot is heated to a temperature of 800-850 DEG C, and then hot-rolled after being kept at the temperature for 15-20 hours to obtain a beryllium copper hot-rolled blank; S3, the beryllium copper hot-rolled blank is sequentially subjected to annealing treatment and face milling; S4, the beryllium copper hot-rolled blank after the face milling is sequentially subjected to rough rolling, edge cutting, solid solution treatment and electric pulse rolling to obtain a beryllium copper alloy strip. The beryllium copper alloy prepared by the application has no cracks under a large deformation, has a large degree of grain crushing, has a small grain size, has good formability, and has a short production flow and high production efficiency.

The invention discloses a hydrophobic anti-sintering indium oxide catalyst as well as a preparation method and application thereof, and belongs to the technical field of carbon dioxide hydrogenation catalysts. The hydrophobic anti-sintering indium oxide catalyst provided by the invention comprises an indium oxide catalyst carrier and a silane layer bonded on the surface of the indium oxide catalyst carrier, wherein the silane layer is formed by reacting a silane compound with hydroxyl on the surface of the indium oxide catalyst; based on the total mass of the hydrophobic anti-sintering indium oxide catalyst, the mass fraction of a silicon element in silane is 0.5-0.9 wt%. The silane is chemically bonded on the surface of the indium oxide carrier, so that sintering and grain growth of indium oxide nanoparticles under a high-temperature reaction condition are remarkably inhibited on the premise of not changing an active crystal phase of the indium oxide carrier, and the adaptability of the catalyst under a harsh working condition of a water-containing product is remarkably improved.