52results about How to "High powder activity" patented technology

The invention discloses a preparation method of tin-based silver graphene lead-free composite solder. The method comprises the steps that a certain amount of graphene and lauryl sodium sulfate are mixed, then a certain amount of dimethylformamide is added, ultrasonic treatment is performed for 2 h, a certain amount of silver nitrate is added into a mixed solution, ultrasonic treatment is performed continuously, and finally a self-made silver graphene nanosheets are obtained; and required solder matrix powder is weighed according to different graphene mass fractions and poured into a ball milling tank for ball milling for 5 h, the powder is placed into a stainless steel mold after being dried and placed under a hydraulic machine to be pressed and molded at the pressure of 500 Mpa, and then a cylinder obtained through cold pressing is placed into a high-vacuum tubular resistance furnace for vacuum sintering for 2 h at the temperature of 175 DEG C and placed under the hydraulic machine after being cooled to the room temperature to obtain a cylinder through impact extrusion. According to the preparation method, Ag-particle-modified graphene is selected as a strengthening material so as to improve load transmitting between the nano-silver-modified graphene and a Sn matrix, and therefore the better strengthening effect is achieved.

The invention provides a method for preparing SmFeN permanent magnet material by mechanical alloying, which is characterized in that pure Sm powder and Fe powder are pressed by Sm 2 Fe 17 1-30% more Sm powder ratio is added, that is, the final mass percentage is 25-30% Sm, 70-75% Fe. In order to increase the infiltration amount of nitrogen, elements that can promote nitriding (such as Cr, Ni, Co, etc.) can also be added, and the mass percentage is about 0.1-2%. After preliminarily mixing the raw material powders, mill them in a high-energy ball mill for 1 to 20 hours. The milling medium is a nitrogen-containing substance. During the milling, stop for 5 to 20 minutes every 5 to 30 minutes to prevent the temperature in the tank from being too high. The invention has the advantages of high nitrogen content, compact structure, and the ability to prepare magnetic properties B r =1.3T, i h c =3390KA / m, (BH) m =395kJ / m 3 SmFeN magnetic powder and bulk material; and realize simple equipment, easy operation, high production efficiency and low cost.

The invention discloses a preparation method of superfine low-sodium alpha-alumina powder with high activity. Industrial aluminum hydroxide is taken as a raw material; alkali is removed and adsorbed by adding an acid; a compound mineralizer is added to calcine; the superfine low-sodium alpha-alumina powder with high activity, of which the mean grain size D50 is 0.2-1.0micron, is obtained by combining dry ball milling with wet ball milling; the sodium content is 0.01%-0.05%; and the content of the alpha phase is 97%-99%. The problems that the alpha-alumina is high in sodium content, uneven in grain size, poor in sintering activity and the like are solved, special requirements of high-performance ceramic, grinding and polishing materials and the like are met, and the method has the advantages of being simple in process, environmentally friendly, low in cost and the like, and is suitable for large-scale production.

The invention discloses a preparation method of tin-based silver graphene lead-free composite solder, which comprises mixing a certain amount of graphene with sodium lauryl sulfate, then adding a certain amount of dimethylformamide, and ultrasonically treating it for 2 hour, then add a certain amount of silver nitrate to the mixed solution, continue ultrasonic treatment, and finally get homemade silver graphene nanosheets; weigh the required solder matrix powder according to different silver graphene mass fractions, pour it into a ball mill jar and mill for 5 hours , put the powder into a stainless steel mold after drying, put it under a hydraulic press and press it at a pressure of 500Mpa, then put the cold-pressed cylinder into a high-vacuum tubular resistance furnace for vacuum sintering at 175°C for 2 hours, and cool to room temperature After that, it is punched into a cylinder under the hydraulic press. The present invention selects the graphene modified by Ag particles as the reinforcement material to improve the load transfer between the graphene modified by nano-silver and the Sn matrix, so as to achieve a better strengthening effect.

The invention provides a ternary boride cermet Mo for overlay welding 2 FeB 2 The alloy powder block is composed of the following raw materials in parts by weight: 20-38 parts of ferroboron, 32-50 parts of molybdenum powder, 7-24 parts of iron powder, 2-4 parts of nanometer titanium carbide powder, and 2-4 parts of yttrium oxide powder. Using iron boron, molybdenum powder and iron powder as raw materials to synthesize Mo by metallurgical reaction 2 FeB 2 When adding an appropriate amount of nano-titanium carbide powder, in the welding metallurgy process, because the melting point of nano-titanium carbide powder is as high as 3140 ° C, it can be used as dispersed Mo in liquid metal 2 FeB 2 Non-spontaneous nucleation core, so that the formed ternary boride Mo 2 FeB 2 Dispersed distribution, so the surfacing metal has excellent high temperature hardness, wear resistance, good toughness and crack resistance. The steps are simple, the operation is convenient and the practicability is strong.

The invention provides an application method of cold field plasma discharge assisted high energy ball milled powder and a plasma assisted high energy ball milling device using the cold field plasma discharge assisted high energy ball milling method. The method comprises the following steps: utilizing dielectric barrier discharge to generate plasmas, introducing a dielectric barrier discharge electrode bar into a high-speed vibrating ball-milling tank, on one hand, requiring a solid insulating medium on the outer layer of the electrode bar to simultaneously bear high-voltage discharge and mechanical shock failure of the grinding ball, and on the other hand, requiring the high-speed vibrating ball milling device to uniformly process the powder. The method is based on the ordinary ball milling technology; the processing efficiency and the effect of the ball mill can be greatly improved by the following steps: under a non-heat-balance discharge condition of the pressure that the discharge space pressure is set to be about 102-106 Pa, introducing the discharge plasmas to input another effective energy to the processed powder, promoting the powder to be processed to be subjected to combined action of the mechanical stress effect and the heat effect of the external electric field, and further accelerating refining of the powder and promoting the alloying progress.

The invention discloses an electric pulse preparation method for dissolved perovskite. The method comprises the following steps: preparing ABO3 perovskite type oxide powder by using a sol-gel method,putting the perovskite type oxide powder into a treatment ceramic casing, connecting two ends of the treatment ceramic casing with pulse electrodes, and performing electric pulse treatment on the ABO3perovskite type oxide powder prepared in the step (1), thereby obtaining a dissolved perovskite oxide, wherein the pulse voltage is 400-700V, the pulse frequency is 1-5Hz, and the pulse treatment time is 30-300 seconds. The method has the advantages that the method is simple, the dissolved perovskite can be prepared safely and efficiently, and the electrochemical properties of the dissolved perovskite as a solid oxide fuel battery anode material are improved.