9 results about "Solvent degreasing" patented technology

The invention discloses a series of azeotropic or azeotrope-like compositions for solvent and single-phase or two-phase cleaning applications, and the formula of the azeotropic or azeotrope-like compositions mainly comprises trans-1, 2-dichloroethylene and hexafluoropropylene dimer; the composition may include at most one of 1, 1, 2, 2-tetrafluoroethyl-2, 2, 2-trifluoroethyl ether or 1, 1, 2, 3, 3, 3-hexafluoropropyl-2, 2, 2-trifluoroethyl ether, for example, 60 to 80% by mass of trans-1, 2-dichloroethylene, 20 to 40% by mass of hexafluoropropylene dimer or 60 to 65% by mass of trans-1, 2-dichloroethylene, or may also include any at most one of 1, 1, 2, 2-tetrafluoroethyl-2, 2, 2-trifluoroethyl ether or 1, 1, 2, 3, 3, 3-hexafluoropropyl-2, 2, 2-trifluoroethyl ether, for example, 60 to 80% by mass of trans-1, 2-dichloroethylene, 20 to 40% by mass of hexafluoropropylene dimer or 60 to 65% by mass of 1, 1, 2, 2- 25 to 30% by mass of a hexafluoropropylene dimer; and 10 to 15% by mass of any one of HFE347 or HFE449. According to the present invention, the component capable of generating the azeotrope-like composition with the trans-1, 2-dichloroethylene component can inhibit the flash point of the trans-1, 2-dichloroethylene component so as to improve the safety performance of transportation, storage and use. The multi-component composition described by the formula can be used for high-efficiency degreasing of metal parts or high-efficiency cleaning of precise devices in the metal processing process, can also be used as a solvent, a degreasing agent, a desoldering agent or a drying agent and the like, and can meet multiple application requirements.

The application discloses a preparation method of a W-Cu component continuous gradient structure contact and the contact, and specifically comprises the following steps: step 1, W powder and a binder are mixed by using a banbury mixer to obtain feed A, and Cu powder and the binder are mixed by using the banbury mixer to obtain feed B; step 2, the feed A and the feed B are mixed and printed and extruded by using a three-screw double-component single-nozzle 3D printer to obtain a W-Cu component continuous gradient structure composite green body; step 3, the W-Cu component continuous gradient structure composite green body is subjected to solvent degreasing, drying and thermal degreasing to obtain a W-Cu component continuous gradient structure composite degreasing body; step 4, the W-Cu component continuous gradient structure composite degreasing body is sintered to obtain a W-Cu component continuous gradient structure composite material; and step 5, the W-Cu component continuous gradient structure composite material is machined to obtain the W-Cu component continuous gradient structure contact. The W phase and the Cu phase in the contact obtained by the method continuously and gradiently change in composition.

The invention belongs to the technical field of metal injection molding blank solvent degreasing, aims to solve the problems of complex solvent degreasing process, long degreasing time and many degreasing defects, and discloses a rapid solvent degreasing method for a wax-based W-Ni-Fe alloy injection molding blank. According to the method, a blank formed by wax-based W-Ni-Fe alloy feed injection molding is degreased, during degreasing, the blank is put into trichloroethylene and degreased in a water bath kettle, the dosage of the trichloroethylene is more than 7 times of the volume of the blank, and the relative degreasing rate is calculated according to the mass of the blank before and after degreasing and the theoretical degreasing rate. According to the method, the degreasing time can be greatly shortened, the degreasing efficiency is improved, blank deformation is small, and component fluctuation cannot be caused.

This invention discloses a method for preparing high-density cobalt-free nano-tungsten carbide cemented carbide, belonging to the field of cemented carbide technology. The preparation method includes the following steps: aluminum powder, copper powder, manganese powder, molybdenum powder, and titanium powder are mixed and then subjected to a first ball milling process to obtain high-entropy alloy powder; nano-tungsten carbide powder, high-entropy alloy powder, tantalum carbide powder, vanadium carbide powder, carbon nanotubes, lanthanum oxide, and yttrium oxide are mixed and then subjected to a second ball milling process to obtain composite powder; paraffin wax, stearic acid, ethylene-vinyl acetate copolymer, and low-density polyethylene are mixed to obtain a binder; the composite powder and binder are kneaded to obtain a compound; the compound is extruded to obtain a green body; the green body is subsequently subjected to solvent degreasing and hot degreasing treatments to obtain a degreased green body; the degreased green body is rapidly hot-pressed and sintered to obtain the high-density cobalt-free nano-tungsten carbide cemented carbide. Through the above scheme, this invention prepares a high-density cobalt-free nano-tungsten carbide cemented carbide with good density, hardness, and oxidation resistance.

The invention discloses a high-density cobalt-free nano tungsten carbide hard alloy and a preparation method thereof, and belongs to the technical field of hard alloys. The preparation method comprises the following steps that aluminum powder, copper powder, manganese powder, molybdenum powder and titanium powder are mixed and then subjected to first ball milling treatment, and high-entropy alloy powder is obtained; nano tungsten carbide powder, high-entropy alloy powder, tantalum carbide powder, vanadium carbide powder, carbon nanotubes, lanthanum oxide and yttrium oxide are mixed and then subjected to second ball milling treatment, and composite powder is obtained; paraffin, stearic acid, ethylene-vinyl acetate copolymer and low-density polyethylene are mixed to obtain a binder; mixing the composite powder and a binder to obtain a mixed material, carrying out extrusion molding on the mixed material to obtain a green body, and sequentially carrying out solvent degreasing and thermal degreasing treatment on the green body to obtain a degreased green body; and the degreased blank is subjected to rapid hot pressing sintering, and the high-density cobalt-free nano tungsten carbide hard alloy is obtained. According to the scheme, the high-density cobalt-free nano tungsten carbide hard alloy with good density, hardness and oxidation resistance is prepared.

The invention discloses a W-Cu composite material with a component continuous gradient structure and a preparation method of the W-Cu composite material. The preparation method comprises the following steps: step 1, preparing a feed A and a feed B from W powder with different particle sizes; 2, the feed A and the feed B are added into a three-screw double-component single-nozzle powder extrusion device to be printed and extruded, and continuous gradient structure printing green bodies with different particle size W contents are obtained; 3, the obtained continuous gradient structure printing green bodies with different particle sizes and W contents are sequentially subjected to solvent degreasing, drying and thermal degreasing treatment, and continuous gradient structure degreasing green bodies are obtained; 4, the obtained continuous gradient structure degreased blank is sintered, and a continuous gradient structure sintered blank is obtained; and 5, the obtained continuous gradient structure sintering blank is subjected to copper infiltration treatment, and the W-Cu composite material of the component continuous gradient structure is obtained. By means of the method, the W-Cu composite material of the continuous gradient structure of the components can be prepared, wherein the W-Cu composite material has high surface arc ablation resistance and overall high electric conduction and heat conduction performance at the same time.

A cemented carbide additive manufacturing method, comprising the specific steps of: (1) preparing uniformly dispersed cemented carbide powder by ball milling; (2) preparing a printing feed by internal mixing; (3) preparing a printing green body by means of fused deposition modeling of the feed; and (4) carrying out degreasing and vacuum pressure sintering on the green body to obtain a cemented carbide product. A cemented carbide solid part which is free of pores, cracks and decarburization, is free of harmful phases such as free carbon and brittle phase, and has simple phase composition, high relative density and excellent comprehensive mechanical properties is prepared by means of green body printing in cooperation with two-step degreasing of solvent degreasing and thermal degreasing and vacuum pressure sintering. Therefore, the present invention effectively solves the problems of cracking, pores, decarburization, brittle phase and deformation, low relative density, poor comprehensive mechanical properties, etc. which make troubles in cemented carbide additive manufacturing for a long time and are difficult to solve by existing additive manufacturing technology. The cemented carbide powder raw material used in an existing powder metallurgy process can be adopted. The prepared cemented carbide product has excellent hardness, strength and fracture toughness. The method is simple, low-cost, and suitable for large-scale production.

The invention provides a method for cleaning sand blowing medium residues or pollutants on the surface of a stainless steel part, and the method is characterized in that on an original passivation production line, white corundum medium residues or pollutants after sand blowing on the surface of the stainless steel part are directly cleaned by using the passivation cleaning effect; the method specifically comprises the following steps: step 1, carrying out solvent oil removal; 2, alkali cleaning and oil removal are carried out; 3, passivating treatment is conducted, specifically, passivating treatment is conducted for at least 40 min in a nitric acid solution with the temperature ranging from 49 DEG C to 54 DEG C and the concentration ranging from 430 g / L to 525 g / L; fourthly, rinsing is conducted, warm water at the temperature of 40-60 DEG C is adopted for cleaning for 1-3 min, and then cold water at the temperature lower than 40 DEG C is adopted for rinsing for at least 2 min till a surface water film is continuous; and 5, drying is conducted, and clean compressed air is used for blow-drying.

The invention belongs to the technical field of nuclear fuel preparation, and provides a metal ceramic fuel preparation method based on powder extrusion printing, which comprises the following steps: weighing matrix powder, fuel phase powder or microspheres and a binder according to a ratio, adding into an internal mixing chamber, carrying out internal mixing granulation and pelletizing to obtain a metal ceramic feed, enabling the metal ceramic feed and the matrix feed to be in a slurry state, and printing to obtain the metal ceramic fuel based on powder extrusion printing. And the printed metal ceramic fuel green body is immersed in a degreasing solvent and heated in a water bath, the green body degreased through the solvent is subjected to thermal degreasing, the metal ceramic fuel green body is heated, a heat preservation point is set, a metal ceramic fuel brown blank is obtained, and the degreased metal ceramic fuel brown blank is subjected to densification sintering. Near-net forming of the metal ceramic fuel pellet in a complex shape can be achieved, and the production and manufacturing difficulty and cost can be reduced.