32results about How to "Excellent and stable mechanical properties" patented technology

The invention provides an HRB400 steel bar and a production method of the HRB400 steel bar. The HRB400 steel bar comprises, by mass, 0.19-0.25% of C, 0.55-0.80% of Si, 1.45-1.60% of Mn, 0.02-0.04% ofV, 0.008-0.010% of N, and the balance Fe and unavoidable impurities. According to the technical scheme, vanadium nitrogen microalloying is used for improving the strength, compared with ferrovanadiummicroalloying, the aim of reducing the cost is achieved, and the HRB400 steel bar has the advantages that mechanical properties are excellent and stable, and the cost is low.

The invention relates to the field of metallurgy, and particularly discloses an HRB400 rebar and a production method thereof. The HRB400 rebar is prepared from 0.19 wt%-0.25 wt% of C, 0.55 wt%-0.80 wt% of Si, 1.45 wt%-1.60 wt% of Mn, 0.20 wt%-0.30 wt% of Cr and the balance iron. The HRB400 rebar has the advantages of being excellent and stable in mechanical property and low in cost.

The invention discloses a preparation method of a rubber shock pad for an engine, and relates to the technical field of rubber products. The preparation method comprises the following steps: weighing the following raw materials in parts by weight: 40-60 parts of deproteinization natural rubber, 20-40 parts of ethylene propylene diene monomer, 20-30 parts of carbon fibers, 20-25 parts of white carbon black, 2-3 parts of stearic acid, 4-6 parts of zinc oxide, 2-4 parts of sulfur, 1.5-2.5 parts of accelerant and 3-5 parts of anti-aging agent; steeping the carbon fibers in a silane coupling agent, and then drying; adding the two types of rubber to an open mill, mixing, after covering rollers with a sizing material, adding the carbon fibers, the white carbon black, the stearic acid, the zinc oxide and the anti-aging agent at twice, finally adding the sulfur and the accelerant for mixing, and standing for 24 hours after forming sheets; and putting a rubber compound on a plate vulcanizing machine so as to vulcanize, and then trimming to obtain the required product. The preparation method can be used for solving the problem that the traditional rubber shock pad for the engine is likely to fatigue and has poor impact resistance and tear resistance.

The invention discloses a graphene-loaded polyimide high-dielectric-permittivity composite film doped with microcrystal glass powder and used for a capacitor. According to the composite film, the microcrystal glass powder, graphene and other filler are doped in the polyimide film preparing process, and the graphene is loaded on the microcrystal glass powder to improve the dispersity and the utilization rate of the microcrystal glass powder. A powder body is covered with a polyvinyl alcohol film good in stability in an organic solvent, and the composite powder body with the surface modified and processed by a silane coupling agent is good in compatibility with an polyamic acid organic glue solution interface and can be evenly dispersed more easily, so that the dielectric permittivity of a material is stably and efficiently improved, and loss is reduced. The dielectric properties of the finally prepared polyimide film pure in composite film material are greatly improved, good mechanical properties and processability are still maintained, heat stability is better, and application prospects are good.

The invention discloses a europium hafnate neutron absorbing material and application thereof. The europium hafnate neutron absorbing material is prepared through a ball milling-isostatic cool pressing-sintering or ball milling-hot pressed sintering technological process by adopting raw materials including hafnium oxide powder and europium oxide powder; the europium hafnate neutron absorbing material always keeps a single fluorite crystal structure within the range from the room temperature to 2200 DEG C; the mass percentage of europium oxide is 55.78 percent by weight to 65.34 percent by weight; and the mass percentage of hafnium oxide is 34.66 percent by weight to 44.22 percent by weight. The europium hafnate neutron absorbing material provided by the invention has excellent and stable combination properties such as neutron absorption, heat conduction, mechanical property and radiation resistance; the transformation of the crystal structure and the decomposition of a phase cannot occur along with the temperature change; and a mixed phase with different crystal structures and a mixed phases with different phases cannot occur in the material.

The invention discloses an ultra-low hydrogen type acid flux-cored wire and a production method thereof. The flux-cored wire is composed of a low-P and low-S steel strip and a flux core wrapped with the steel strip, wherein a welding flux accounts for 10%-20% of the total weight of a welding wire. The production method comprises the steps that after a heating process is carried out before and after a forming process to remove residual oil, the flux core is wrapped with the low-P and low-S steel strip through a precision forming process, and then the welding wire is obtained through diameter reduction, wire drawing and wire take-up. The flux-cored wire has excellent welding process performance, deposited metal of the flux-cored wire is excellent and stable in mechanical performance, the diffusible hydrogen content of the deposited metal of the flux-cored wire is reduced to an ultra-low hydrogen level (smaller than 3 ml/100 g, and a mercury method), and therefore a weld joint has good cold crack resistance.

The invention discloses a 9% Ni steel matched nickel-based welding rod special for overhead welding. The welding rod is composed of a welding core and a coating, wherein the outer wall of the weldingcore is coated with the coating, the coating accounts for 0.3-0.5% of the total weight coefficient of the welding rod, the welding core is a nickel-chromium-iron welding core, and the coating is composed of a CaCO3-MgCO3-CaF2 low-hydrogen slag system with high alkalinity. The welding rod has excellent all-position weldability, especially overhead welding position weldability, and extremely low overhead welding shooting porosity; and the welding rod has excellent overhead welding property, stable electric arc, excellent deslagging property and excellent weld joint forming property, the weldingrod has extremely low overhead welding porosity, and the overhead welding high-definition radiographic inspection TOFD shooting qualification rate can reach 99.5% or above.

The invention provides a die for preparing a long and thin ceramic pipe blank through alternated die pressing and an application method of the die. The problems existing in preparing of long and thin ceramic pipes through a conventional die pressing manner in the prior art are solved; and in other words, the problem that the long and thin ceramic pipes are hard to prepare through one-way die pressing and both-way die pressing is solved, and the problems of the complex technology, the long period, the high cost and the like in static pressure preparing of the long and thin ceramic pipes are solved. The method adopted for preparing the long and thin ceramic pipe blank has the beneficial effects of being simple in technology, short in period, low in cost and the like, and a sintered ceramic pipe component is uniform in microstructure and excellent and stable in mechanical performance.

The invention discloses a brazing flux-free brazed aluminum alloy composite strip and a manufacturing method thereof. The brazing flux-free brazed aluminum alloy composite strip comprises a core layerand brazing layers, wherein the brazing layers are arranged on the two sides of the core layer. The brazing layers are made of aluminum-silicon alloy, and the aluminum-silicon alloy is prepared from,in percent by weight: smaller than or equal to 0.25% of Fe, 7.8-8.2% of Si, smaller than or equal to 0.05% of Cu, smaller than or equal to 0.05% of Mn, smaller than or equal to 0.01% of Mg, smaller than or equal to 0.001% of Sr, smaller than or equal to 0.05% of Ti, smaller than or equal to 0.05% of each of other elements and the balance Al. Alloy components and structures are controlled throughformula adjustment and ingot casting procedures, then the rolling procedure is conducted, the composite strip has excellent and stable mechanical properties, the tensile strength and yield strength ofthe prepared finished strip are high, the brazing structure is uniform and fine, and the brazing strength is high; and brazing flux is not contained, the brazing performance is stable, the brazing quality is good, the service life of a heat transfer material is prolonged, the production efficiency is improved, and therefore the cost is reduced.

The invention discloses a drying method for Typha angustifolia. The drying method comprises the following steps: (1) first-stage drying; (2) second-stage drying; and (3) third-stage drying. Each stage of the method is carried out on the basis of the characteristics of drying of Typha angustifolia; through the steps, the drying time for Typha angustifolia in the invention is shortened by 30% or more compared with conventional methods, the loss rate of Typha angustifolia is reduced by about 3%, the mechanical properties like flexibility and strength of Typha angustifolia are excellent and stable, and dried Typha angustifolia has a uniform and consistent color as a whole and is not prone to mildew or color changing after long-term storage; and high-quality and detailed technical support is provided for drying of Typha angustifolia, and the method has good promotion value.

The invention relates to chemically modified silicone rubber and a preparation method thereof. The product developed by the invention comprises silicone rubber, petroleum resin and linear silicone oil, the petroleum resin is aminopropyltriethoxysilane modified petroleum resin, and the silicone rubber and the aminopropyltriethoxysilane modified petroleum resin are crosslinked to form a three-dimensional network structure; and gaps of the three-dimensional cross-linked network structure are filled with the linear silicone oil. The preparation method of the chemically modified silicone rubber comprises the following steps: reacting hydrogenated petroleum resin with epoxy chloropropane to obtain hydrogenated petroleum resin glycidyl ester; heating the hydrogenated petroleum resin glycidyl ester and aminopropyltriethoxysilane, stirring and reacting under the protection of inert gas, and obtaining aminopropyltriethoxysilane modified petroleum resin; then mixing the silicone rubber, the aminopropyltriethoxysilane modified petroleum resin and an organic tin catalyst, heating and stirring for reaction, and then carrying out hot-pressing curing to obtain the product.

The invention discloses a method for preparing an uvioresistant APET composite film. The method comprises the following steps: a) selecting and preparing materials; 2) preparing a functional composite agent; c) performing dry compounding treatment; and d) performing after treatment on the film. The invention discloses a method for preparing the uvioresistant APET composite film. The method is reasonable in procedure arrangement, scientific in application process and moderate in cost; the prepared composite film is high in interlayer combination strength and excellent and stable in mechanical property and has an outstanding and long-lasting uvioresistant function, and the practicability of the APET film is effectively improved.

The invention discloses a high temperature-resistant solvent-based polyurethane material with the monomer structure containing a biphenylphthalazine structure, and a preparation method thereof. The defects of poor high temperature resistance and poor radiation resistance of traditional solvent-based polyurethane materials are overcome from the perspective of the design of the molecular structure of a polymer. The polyurethane material designed in the invention is prepared by polymerizing diisocyanate, polyether or polyester polyol, a chain extender, a catalyst, an end capping agent, and a monomer containing the biphenylphthalazine structure. The polyurethane material not only improves the heat resistance and the radiation resistance of the polyurethane material, and also maintains excellent mechanical properties, and cured products of the polyurethane material can be used for a long period under a high temperature (200 DEG C) condition.