33results about How to "Avoid mechanical performance degradation" patented technology

The invention provides an atomization adding device and an atomization adding method for a neodymium iron boron magnetic powder mixing additive. Specifically, the atomization adding device for the neodymium iron boron magnetic powder mixing additive comprises a storage barrel, a weighing barrel, a control system, a connecting rod, a blocking piece and a powder container, wherein the storage barreland the weighing barrel are in flexible connection, the weighing barrel is connected with the control system through a weighing sensor, the weighing barrel and the powder container are connected through the connecting rod, and the blocking piece is arranged at an opening of the powder container, and the connecting rod penetrates through the blocking piece to extend into the powder container. Whenthe atomization adding device for the neodymium iron boron magnetic powder mixing additive is used for adding, the adding device is not in direct contact with the powder, and the air replacement process of the connecting part is introduced, so that oxidation caused by contact of oxygen and the powder in the additive adding process of neodymium iron boron powder and caking and blocking of the powder at an adding opening can be effectively avoided; and therefore, the use, cleaning and maintenance are simple; And meanwhile, atomized additive liquid drops are directly sprayed to the powder duringaddition and cannot be sprayed to the inner wall of the container to cause caking of the powder on the wall of the tank, so that the accuracy of the additive addition amount and the mixing uniformityare improved.

The invention discloses a method for preparing a high-temperature-resistant reinforced and toughened Ox / Ox composite material, and relates to the technical field of ceramic-based composite materials. The present invention first adopts the mixed solution of ammonium dichromate and anhydrous oxalic acid to pre-treat the alumina fiber fabric by impregnation-heat treatment to obtain the surface-coated alumina fiber, and then put it into CVI to prepare pyrolytic carbon coating or BN coating. The nanowire coating is obtained by electrophoretic deposition on the coating, and then the alumina ceramic slurry is coated on the surface of the alumina fiber fabric with the nanowire coating for hot pressing and sintering to obtain a high-performance Ox / Ox composites. The invention provides a method for preparing a high-temperature-resistant reinforced and toughened Ox / Ox composite material, which obtains a high-density matrix and a porous nano-oxide coating, so that a weak interface is formed between the alumina fiber and the alumina matrix, thereby obtaining A high-strength, high-toughness, high-temperature-resistant alumina fiber-reinforced alumina matrix composite was developed.

The invention discloses a microcellular foam injection molding process with high foaming magnification and no bubble marks on the surface, including: mixing of polymer melt and foaming agent, preform forming, preform transfer, heating foaming, and obtaining after coolingFinal product.Among them, the preform and the final product are formed in two different volume mold cavities.High cavity pressure, high injection pressure and high holding pressure are used to prevent foaming during preform molding. After the cooled preform is fixed in the forming cavity of the final product, the mold is closed and the mold is heated to foam the interior of the preform.The high-pressure injection process of the preforms can avoid defects such as silver lines, spiral lines, and blisters on the surface of the product, and the volume difference between the preforms and the final product provides space for bubble nucleus growth. The process can be used to produce microcellular foamed injection molded parts with good surface quality and dense internal cells.

The invention relates to a segmentally rolling method for a large-scale high-temperature alloy high-cylindrical forging piece. The segmentally rolling method for the large-scale high-temperature alloyhigh-cylindrical forging piece comprises the steps of after heating, forging, chambering a blank and pulling a central spindle, firstly adopting a segmental irregular mold for segmentally and locallyrolling the annular blank, and then adopting a direct-wall mold for integrally rolling the segmentally and locally rolled annular piece, wherein the segmental irregular mold comprises an irregular main roller and an irregular core roller, the roller surfaces of the irregular main roller and the irregular core roller locally contact a wall surface of the annular blank, the direct-wall mold comprises a direct-wall main roller and a direct-wall core roller, the roller surfaces of the direct-wall main roller and the direct-wall core roller partially contact the blank during the rolling process and integrally contact the blank after rolling; and coating a heat-insulation coating on the roller part of the segmentally rolled annular piece, so that the integral mechanical property of the annularpiece during a follow-up rolling process is ensured. Through the method, the utilization ratio of the material and the mechanical property and the quality of the material can be improved, and meanwhile, the requirement for the rolling force of the equipment is lowered.

The invention relates to a preparation method for improving the mechanical property of a giant magnetostrictive material, and belongs to the field of magnetic materials. The preparation method concretely comprises the following steps of preparing a giant magnetostrictive material terbium-dysprosium-iron alloy with specific orientation through blending, vacuum smelting and directional solidification; placing a sample to be treated into a heat treating furnace, vacuumizing to 0.01 Pa, and then starting heating; continuously vacuumizing in a temperature increasing process; after the temperature inside the heat treating furnace is increased to 800-1200 DEG C, stopping vacuumization; introducing high-purity argon to increase the pressure inside the heat treating furnace to 1-20 MPa, and preserving the heat for 30-180 minutes; after heat preservation is finished, stopping heating, and after the sample is cooled, taking out. According to the invention, the growth of an RFe2 phase contained in the terbium-dysprosium-iron alloy can be inhibited through high-pressure heat treatment; the holes and microcracks can be decreased by regulating the diffusion and separation of a rare earth-rich phase; the coalescence of the microcracks of the material is promoted, so that the mechanical property of the giant magnetostrictive material can be improved, the waste, which is caused due to poor mechanical property, of the material is reduced, and the requirement for usage under the condition of more working conditions is met. The preparation method disclosed by the invention is easy to operate and suitable for industrialized production.

The invention belongs to the field of aluminum alloy materials and discloses a high-strength weldable aluminum alloy. The high-strength weldable aluminum alloy includes the following components: 0.4-1.2% Mg, 0.7-1.4% Si, 0.2-0.7% Mn, 0.05-0.2% %Cu, 0.1‑0.5% Zn, 0.4‑0.6% Fe, 0.05‑0.15% Cr, 0.1‑0.3% other alloying elements, the balance is Al; other alloying elements include Ni, V, Ti, Zr, rare earth elements Combination, the ratio is 1.2-1.4: 0.6-0.8: 2.4-2.6: 0.4-0.6: 0.2; the rare earth elements include: Ce, La, Er, wherein Ce accounts for more than 60% of the total amount of rare earth elements. The aluminum alloy of the present invention improves the strength and mechanical properties through the improvement of the original formula, and can be used as aluminum alloy parts in the power battery of new energy vehicles, such as end plates, trays and the like.