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CN-122007437-A - Method for preparing lattice configuration magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing

CN122007437ACN 122007437 ACN122007437 ACN 122007437ACN-122007437-A

Abstract

The invention discloses a method for preparing a lattice configuration magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing, belonging to the technical field of additive manufacturing of metal materials. Solves the problems of poor component stability and high time cost of the existing additive manufacturing method related to the adhesive when preparing the magnetic shape memory alloy. The method comprises the steps of preparing slurry, printing, and sintering. The invention is used for preparing the lattice configuration magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-section degreasing.

Inventors

  • QIAN MINGFANG
  • ZHONG SHIJIANG
  • WANG RUNYU
  • ZHANG XUEXI
  • GENG LIN

Assignees

  • 哈尔滨工业大学

Dates

Publication Date
20260512
Application Date
20260213

Claims (10)

  1. 1. A method for preparing a lattice-structured magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing is characterized by comprising the following steps: 1. Preparation of the slurry: Firstly, preparing nickel-manganese-tin-cobalt alloy powder by an air atomization method, mixing the nickel-manganese-tin-cobalt alloy powder, a sodium alginate solution, a surfactant aqueous solution and microcrystalline cellulose to obtain a mixture, and ball-milling the mixture to obtain nickel-manganese-tin-cobalt alloy slurry; 2. Printing: Performing multilayer printing on the surface of the substrate by using nickel-manganese-tin-cobalt alloy slurry under the conditions that the substrate temperature is 305K-315K, the inner diameter of a printing needle is 0.24 mm-0.30 mm, the extrusion pressure is 0.12 MPa-0.25 MPa and the printing speed is 4 mm/s-8 mm/s, so as to obtain a nickel-manganese-tin-cobalt lattice member; The nickel-manganese-tin-cobalt lattice member is a lattice structure formed by staggered and stacked layers; 3. sintering: Placing the sealed quartz tube into a tube furnace, heating up to 773K-973K at a heating rate of 8K/min-10K/min, keeping the temperature for 15-30 min at a temperature of 773K-973K, heating up to 1228K-1238K at a heating rate of 8K/min-10K/min, keeping the temperature for 1 h-2 h at a temperature of 1228K-1238K, and cooling at a cooling rate of 15K/min-25K/min to obtain the magnetic shape memory alloy with excellent magnetic refrigeration performance.
  2. 2. The method for preparing the lattice-structured magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing according to claim 1, wherein the chemical formula of the nickel-manganese-tin-cobalt alloy powder in the first step is Ni 41 Mn 43 Sn 10 Co 6 , and the particle size of the nickel-manganese-tin-cobalt alloy powder in the first step is less than or equal to 15 mu m.
  3. 3. The method for preparing the lattice-structured magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing according to claim 1 is characterized in that the concentration of sodium alginate solution in the step one is 3-8wt%, the aqueous surfactant solution in the step one is pluronic F-127 aqueous solution with the concentration of 20-40wt%, the mass ratio of nickel-manganese-tin-cobalt alloy powder to sodium alginate solution in the step one is 1 (0.08-0.12), the mass ratio of nickel-manganese-tin-cobalt alloy powder to the aqueous surfactant solution in the step one is 1 (0.01-0.02), and the mass ratio of nickel-manganese-tin-cobalt alloy powder to microcrystalline cellulose in the step one is 1 (0.02-0.04).
  4. 4. The method for preparing the lattice-configuration magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing according to claim 1 is characterized by comprising the following steps of taking zirconia balls with the diameter of 4-6 mm as grinding balls, and ball-milling the mixture for 1.5-2 h under the conditions that the ball mass ratio is (4-7): 1 and the rotating speed is 1100-1300 r/min, so as to obtain nickel-manganese-tin-cobalt alloy slurry.
  5. 5. The method for preparing the lattice-configuration magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing according to claim 1, wherein the viscosity of the nickel-manganese-tin-cobalt alloy slurry in the step one is 5×10 3 Pa•s~7×10 3 pa.s at room temperature.
  6. 6. The method for preparing the lattice-configuration magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing according to claim 1, wherein the substrate in the second step is an alumina plate covered with a plastic film.
  7. 7. The method for preparing the lattice-configuration magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing according to claim 1, wherein the temperature of a printing cabin in the printing process in the step two is 255-303K, and the relative humidity of the printing cabin is 30-50%.
  8. 8. The method for preparing the lattice-configuration magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing according to claim 1, wherein the lattice spacing of the lattice structure in the second step is 0.75-1.10 mm, the diameter of lattice lines is 0.28-0.35 mm, the pore channels of the lattice structure are vertically penetrated, the layer height of each layer of structure in the nickel-manganese-tin-cobalt lattice member in the second step is 0.20-0.28 mm, each layer of structure is composed of a plurality of parallel lines, and the rotation angle between two adjacent layers is 60-90 degrees.
  9. 9. The method for preparing the lattice-configuration magnetic shape memory alloy with excellent magnetic refrigeration performance through extrusion molding and two-stage degreasing is characterized in that the mass ratio of manganese powder to nickel-manganese-tin-cobalt lattice members in the third step is 1 (0.8-1.2), the mass ratio of manganese powder to titanium sponge in the third step is 1 (0.2-0.4), the powder particle size of the manganese powder in the third step is 15-53 mu m, the porosity of the titanium sponge in the third step is 70-85%, the manganese powder in the sealed quartz tube in the third step is located at a position which is 2-4 cm away from the bottom of the quartz tube, the nickel-manganese-tin-cobalt lattice members are located at a position which is 7-10 cm above the manganese powder, the titanium sponge is located at a position which is 5-7 cm above the nickel-manganese-tin-cobalt lattice members, and the nickel-manganese-tin-cobalt lattice members are tightly adhered to the inner wall of the quartz tube by using magnets.
  10. 10. The method for preparing the lattice-structured magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing according to claim 1 is characterized in that vacuumizing and argon gas introduction in the step three are specifically carried out according to the following steps of vacuumizing for 5 min-10 min to enable the vacuum degree in a quartz tube to be below 10 -4 Pa, then recharging high-purity argon gas with 1 atmosphere, repeating vacuumizing and argon recharging for a plurality of times, and finally recharging high-purity argon gas with 3X 10 3 Pa~5×10 3 Pa for protection, wherein the purity of the high-purity argon gas is 99.999%.

Description

Method for preparing lattice configuration magnetic shape memory alloy with excellent magnetic refrigeration performance by extrusion molding and two-stage degreasing Technical Field The invention belongs to the technical field of additive manufacturing of metal materials. Background Modern society continues to face serious energy and environmental challenges, wherein refrigeration technology consumes about 20% of the world's electricity generation, and the problems of high-energy consumption equipment such as air conditioners and refrigerators are increasingly prominent. Although the vapor compression refrigeration technology in the dominant market has been developed for more than two hundred years, the inherent defects of the actual efficiency of only 30-40% of the Carnot cycle, high operation noise, difficult miniaturization, dependence on greenhouse gas working media and the like still exist. Under the background, the solid-state magnetic refrigeration technology based on the magnetocaloric effect has the advantages of high energy efficiency and environmental friendliness, and has become a leading research direction for solving the problems of energy and environment by replacing the traditional vapor compression refrigeration. The efficiency core of a solid state magnetic refrigeration system depends on the performance of the solid refrigerant. The ideal material needs to generate significant isothermal entropy change (delta S m) and adiabatic temperature change (delta T ad) under the change of a magnetic field, and has high-efficiency heat exchange capability. Among the numerous candidate materials, the magnetic shape memory alloy has the multifunctional characteristics of shape memory effect, super elasticity, giant magneto-thermal effect, elasto-thermal effect, multi-card effect and the like by virtue of unique martensitic transformation, and the working temperature range covers room temperature, so that the magnetic shape memory alloy has important practical value in the field of solid-state refrigerators. The nickel-manganese-tin shape memory alloy only contains low-cost and nontoxic elements, and has the advantages of environmental protection and economy. In addition, the magnetization property of the nickel-manganese-tin alloy can be further enhanced by doping cobalt into the nickel-manganese-tin alloy. Therefore, the nickel-manganese-tin-cobalt alloy system is of great interest and is expected to become a breakthrough solid refrigeration working medium in a magnetocaloric refrigeration system. The realization of high-efficiency magnetic refrigeration requires large magnetic entropy change, low hysteresis consumption and high thermal conductivity to strengthen the magnetocaloric effect and heat exchange, and simultaneously requires the construction of an optimal geometric structure with high specific surface area to strengthen heat transfer. However, nickel-manganese based alloys exhibit an inherently high brittleness as intermetallic compounds, are difficult to process into complex geometries, and severely limit their engineering applications. The additive manufacturing technology has advantages over traditional manufacturing in terms of rapid prototyping, complex structural design and material processing cost through a layer-by-layer printing strategy, and provides a new path for breaking through the processing bottleneck of brittle materials. Common printing methods for magnetic shape memory alloys are laser powder bed melting (Laser Powder Bed Fusion), binder jetting (Binder Jetting), material extrusion (Material Extrusion). The patent number CN116251963B is entitled "Nickel-manganese-tin-cobalt alloy with room temperature magnetic phase transition performance, and efficient additive manufacturing method and application thereof," nickel-manganese-tin-cobalt alloy powder is prepared by an air atomization method, and a laser powder bed melting technology is used for forming metal powder into a block alloy part. The method can not solve the crack defect generated under the unbalanced condition, so that the magnetic domain continuity is poor, and the saturation magnetization intensity of the alloy under the 5T magnetic field is low. The patent number CN117226107A is named as a porosity-controllable additive manufacturing method of nickel-manganese-tin-cobalt alloy and application of the obtained product, and the nickel-manganese-tin-cobalt alloy is prepared by using binder spraying. The method avoids the problem that the magnetic thermal performance is reduced due to the generation of the second phase by short-time sintering, but the flow takes longer, the production cost is higher, and the magnetic thermal performance of the obtained product still has room for improvement. Nickel-manganese-based magnetic shape memory alloys are difficult to directly apply to material extrusion additive manufacturing processes because of their high sensitivity to composition, organization, and phase change behavi