7results about How to "Dense tissue" patented technology

The application provides a wear-resistant composite piercing mill head manufacturing method and a piercing mill head, and the manufacturing method comprises the following steps: S1, preparing a steel base head; S2, adopting a submerged-arc welding process to make a flux-cored wire cladded on a working cone surface and a nose end surface of the steel base head, so as to form a cladding layer with a thickness of 6-8 mm; and S3, pre-oxidizing the cladding layer of the steel base head at high temperature, so that the wear-resistant composite piercing mill head is obtained. The wear-resistant composite piercing mill head manufacturing method has a dense and uniform oxide film on the surface of the cladding layer of the piercing mill head, the oxide film is firmly combined with the cladding layer, and the existence of the dense and uniform oxide film can reduce the power consumption of a steel pipe piercing mill and prolong the service life of the piercing mill head.

This invention relates to the field of electronic paste preparation technology, and discloses a low sheet resistance tungsten-copper electronic paste and its preparation method, comprising the following steps: Step 1, preparing tungsten-copper composite powder: spherical tungsten powder with a diameter of 1-10 μm and copper powder with a size of 1-3 μm are mixed by mechanical mixing, with a tungsten to copper weight ratio of 3:1-6:1. Before mixing, the copper powder needs to undergo graphene coating pretreatment; Step 2, preparing an inorganic binder: the inorganic binder includes, but is not limited to, the following components: glass powder, CuO, TiO2, La2O3, Pu6O11; Step 3, preparing an organic carrier: the organic carrier includes a solvent, an organic binder, and a thickener; Step 4, preparing the tungsten-copper paste. The tungsten-copper paste of this invention has widely available raw materials, a simple preparation process, and is suitable for mass production. Although graphene, a high-priced material, is added, the amount added is small and the performance is particularly excellent, making the cost of the tungsten-copper paste of this invention far lower than that of similar foreign products, resulting in a very high cost-performance ratio.

This invention discloses a method for producing 8011 aluminum alloy flat ingots using a graphite crystallizer, comprising the steps of graphite crystallizer preparation, smelting, casting, sawing, and milling. The graphite crystallizer uses graphite plates prepared by hot isostatic pressing, with a carbon mass fraction ≥99.9%, density 1.6–1.85 g / cm³, average graphite particle size <25 μm, thermal conductivity 80–130 W / (m·K), porosity 13–15%, and a graphite plate thickness of 10–20 mm and a height of 95–105 mm. The large-face water cavity of the crystallizer has a length of 2450–2550 mm and a height of 155 mm, while the small-face water cavity has a width of 500–670 mm and a height of 155 mm. The cooling water pressure is controlled at 0.25–0.50 MPa. This invention improves the production quality of 8011 aluminum alloy flat ingots, reduces the defect rate, extends the service life of the crystallizer, and increases production efficiency and product qualification rate by precisely optimizing the material and structural parameters of the graphite crystallizer and designing smelting, casting, sawing and milling processes that are compatible with 8011 aluminum alloy.

The utility model discloses a multi-positioning step parting low-pressure casting mold which comprises a mold body, the mold body is of a left-right parting main body structure made of ZG310-570 cast steel, and the left-right parting main body structure comprises a left upper half mold, a left lower half mold, a right upper half mold and a right lower half mold. The left-right parting main body structure is transversely provided with a left-right symmetrical parting surface and is longitudinally provided with a curved surface step parting surface with a 35-degree dip angle. The repeated positioning precision of the mold is improved to + / -1mm through a three-stage positioning system, the position precision of a multidirectional boss is improved by 60%, the error rate is reduced by 30%, the product percent of pass reaches 96.5% by combining effective limiting of a curved surface step parting surface on a boss on the outer surface of a casting, and meanwhile, by means of the synergistic effect of a composite exhaust system and a longitudinal grading water gap system, the product quality is improved. And the air hole defect rate is controlled to be below 0.8%, the feeding problem at the hot spot is effectively solved, the casting quality and the production efficiency are remarkably improved, and the production requirements of high-end precision castings are met.

This invention discloses a near-net-shape aluminum-based composite material part manufacturing method and part. The manufacturing method includes: establishing a three-dimensional part model of the part to be manufactured, wherein the part model has a built-in double-helix siphon microchannel; slicing the part model to obtain slice data for each layer, wherein the slice data includes the geometry and printing path of the part in that layer; printing the part model using sand mold printing according to the slice data to obtain a preform, wherein after printing each layer, a binder is sprayed onto the powder layer used for printing; the preform is sequentially sintered, post-treated, and pre-treated to obtain a treated preform; the treated preform is placed in a pre-fabrication container, impregnated with molten aluminum, and then slowly cooled and solidified to obtain the part to be manufactured. This invention solves the problems of high processing difficulty and difficulty in controlling the precision of aluminum-based composite material parts in the prior art.

The application discloses a Cr2N chromizing nitriding layer on a stainless steel surface, which is composed of a nitriding layer with Cr2N as a main phase; and the application also discloses a preparation method of the chromizing nitriding layer. ‑4 Pa, and then argon gas is introduced to prepare a chromizing layer; step two, preparation of the chromizing nitriding layer: after the preparation of the chromizing layer in step one is completed, the surface metallurgy equipment is vacuumized to 1.0*10 ‑2 Pa again, and then nitrogen gas and argon gas are introduced to prepare the chromizing nitriding layer. The preparation method of the application can effectively reduce the reaction temperature and shorten the reaction time, removes the powder loading and powder removing processes in the embedding chromizing-solid solution nitriding technology, greatly shortens the production cycle, avoids the dust pollution problem, and is suitable for industrial production.