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CN-122012970-A - Powder sintering preparation method of nickel-titanium-based composite material and nickel-titanium-based composite material

CN122012970ACN 122012970 ACN122012970 ACN 122012970ACN-122012970-A

Abstract

The invention discloses a powder sintering preparation method of a nickel-titanium-based composite material and the nickel-titanium-based composite material, and belongs to the technical field of powder metallurgy and composite materials. The method comprises the steps of taking metallic nickel and titanium as raw materials, carrying out induction melting and vacuum atomization to obtain nickel-titanium atomized powder, mixing the nickel-titanium atomized powder with nanoscale reinforcing phase powder, carrying out low-energy ball milling to obtain composite powder with reinforcing phase coated on the surfaces of nickel-titanium particles, and carrying out spark plasma sintering to obtain the nickel-titanium matrix composite material under the conditions of high vacuum, specific pressure, temperature and pulse current. The composite material generates a reinforcing phase distributed in a network at a grain boundary in situ, has R martensitic transformation characteristic and linear super elasticity, has stable super elasticity curve after tens of thousands of loading and unloading cycles, has zero residual strain, has compression fracture strength higher than 2500 MPa and obviously improves hardness. The method has simple process and strong controllability, and is suitable for large-scale preparation of the nickel-titanium-based composite material with high hardness and high cycle stability.

Inventors

  • GAO YI
  • SUN WEN
  • PAN ZHIJIE
  • LI GUOWEI

Assignees

  • 中国科学院宁波材料技术与工程研究所

Dates

Publication Date
20260512
Application Date
20260210

Claims (10)

  1. 1. The powder sintering preparation method of the nickel-titanium-based composite material is characterized by specifically comprising the following steps of: Step S1, sequentially carrying out induction smelting and vacuum atomization by taking metallic nickel and metallic titanium as raw materials to obtain nickel-titanium atomized powder; S2, mixing nickel titanium atomized powder and reinforcing phase powder, and performing low-energy ball milling treatment in an inert atmosphere to obtain mixed powder; And step S3, sintering the mixed powder obtained in the step S2 by adopting a spark plasma sintering method under a high vacuum condition to obtain the nickel-titanium-based composite material.
  2. 2. The powder sintering preparation method according to claim 1, wherein in the step S1, the atomic ratio of metallic nickel to metallic titanium is (40-60): 60-40.
  3. 3. The powder sintering process according to claim 1, wherein the nickel titanium atomized powder obtained in the step S1 has a mass ratio of not smaller than 15. Mu.m, and/or a particle diameter of not smaller than 50%, In the step S2, the particle size of the nickel titanium atomized powder is less than or equal to 15 mu m, and the particle size of the reinforcing phase powder is less than or equal to 50 nm.
  4. 4. The powder sintering preparation method according to claim 1, wherein in the step S2, the reinforcing phase powder is selected from one of silicon carbide, boron nitride, scandium oxide, zinc oxide, and carbon powder, and the reinforcing phase powder accounts for 0.1-10 vol% of the nickel titanium atomized powder in terms of volume ratio.
  5. 5. The method of preparing powder sintered according to claim 1, wherein in step S2, the nickel titanium atomized powder and the reinforcing phase powder are mixed in a powder mixer, and then subjected to low energy ball milling in a nitrogen/argon atmosphere, wherein the mixing time is not less than 2h, and the low energy ball milling time is 5-12 h.
  6. 6. The powder sintering preparation method according to claim 1, wherein in the step S3, parameters of the spark plasma sintering method are as follows, a vacuum degree of 10 -4 -10 -3 Pa, a sintering pressure of 40-60 MPa, a heating rate of 50-100 ℃ per minute, and a sintering temperature of 1000-1200 ℃.
  7. 7. The powder sintering preparation method according to claim 1, wherein in the step S3, the sintering treatment is performed with a pulse current of 2 to 80 ms and a sintering time of 5 to 15 min.
  8. 8. The powder sintering process according to claim 1, wherein when the reinforcing phase powder in step S2 is silicon carbide, the grain boundary reinforcing phase in the nickel-titanium-based composite material obtained in step S3 is Ti w Ni x Si y C z , and the range of atomic percentage is 25 w 31,34 x 40,11 y 13,11 z 13; When the reinforcing phase powder in the step S2 is boron nitride, the grain boundary reinforcing phase in the nickel-titanium-based composite material prepared in the step S3 is Ti x N y B z , and the atomic percentage range is that x is more than or equal to 50 and less than or equal to 52,48 and y is more than or equal to 50 and z is more than or equal to 0 and less than or equal to 2; When the reinforcing phase powder in the step S2 is scandium oxide, the grain boundary reinforcing phase in the nickel-titanium-based composite material prepared in the step S3 is Ti x Sc y O z , and the atomic percentage range is 21 x 26,13 y 15,62 z 64; When the reinforcing phase powder in the step S2 is zinc oxide, the grain boundary reinforcing phase in the nickel-titanium-based composite material prepared in the step S3 is Ni w Ti x Zn y O z , and the atomic percentage range is 0 w 9,0 x 29,14 y 20,55 z 60; When the reinforcing phase powder in the step S2 is carbon powder, the grain boundary reinforcing phase in the nickel-titanium-based composite material prepared in the step S3 is TiC.
  9. 9. The nickel-titanium-based composite material prepared by the powder sintering preparation method according to any one of claims 1 to 8, wherein the nickel-titanium-based composite material generates a reinforcing phase in situ at a grain boundary, and the reinforcing phase has a network structure.
  10. 10. The nickel-titanium matrix composite of claim 9, wherein the nickel-titanium matrix composite has an R martensitic transformation and linear superelasticity at room temperature, wherein the stress-strain curve remains stable over more than ten thousand loading and unloading cycles, the hysteresis area is less than 1MJ/m 3 , and the compressive fracture strength is greater than 2500 MPa.

Description

Powder sintering preparation method of nickel-titanium-based composite material and nickel-titanium-based composite material Technical Field The invention relates to the technical field of powder sintering methods and composite materials, in particular to a powder sintering preparation method of a nickel-titanium-based composite material and the nickel-titanium-based composite material. Background In order to improve mechanical properties and cutting properties, it is also necessary to increase the hardness of NiTi alloys. This is because, when the NiTi alloy is used in medical applications such as vascular stents and orthopedic implants, it is in a dynamic load or friction environment, and the performance may be reduced due to surface wear, so that the hardness is improved, the wear may be reduced, and the device life may be prolonged. High stiffness is often accompanied by higher yield strength and resistance to plastic deformation, which is critical for applications where high loads are required for aerospace fasteners, robotic actuators, and the like. The NiTi alloy is easy to stick a cutter and harden during processing, and the cutting performance can be improved by improving the hardness, and the subsequent surface treatment is convenient. In recent years, researchers have further improved mechanical properties and hardness by adding reinforcing phases to NiTi alloys to form metal matrix composites. These reinforcing phases are typically ceramic materials of high modulus of elasticity, high strength and high stiffness. Al 2O3 particles with different particle sizes are added into the Ni-Ti powder, the Al 2O3 particles are dispersed and distributed in the composite material, the finer the added Al 2O3 particles are, the higher the hardness of the obtained composite material is, and the highest 636HV (METALS AND MATERIALS International, 30 (4) (2024) 843-856) can be achieved. Through Ni, ti, siC powder mixing and sintering, the NiTi/SiC alloy is prepared, siC nano particles are dispersed and distributed in a substrate, meanwhile, various second-phase particles (Ni 4Ti3、Ni2Ti、Ni3 Ti) are formed, the alloy matrix is obviously strengthened under the combined action of the dispersed and distributed SiC nano particles and the second-phase particles, and the strength of the substrate is improved (MATERIALS LETTERS, 100 (2013) 74-77). The NiTi-Ni3 Ti/SiC nanocomposite is prepared by mechanical alloying and microwave assisted sintering technology, and the dispersed SiC particles increase the number of Ni 3 Ti hard phases and improve the hardness of the composite (Ceramics International, 49 (14) (2023) 2358-2366). The mechanism for improving the hardness of the NiTi composite material prepared by the method is that ceramic materials are dispersed and distributed on a substrate, so that the formation of a second phase is promoted, grains are refined, and ceramic particles do not react with NiTi to generate new compounds. Meanwhile, although the distribution of ceramic particles on the substrate effectively improves the hardness, the cyclic stability of superelasticity is not considered. Superelasticity using NiTi alloys has been applied in the fields of robotics, aerospace, medical and mechanical, etc. But because NiTi requires stabilization of the tissue through mechanical cycling training and has limited fatigue life and cycling stability. In order to accelerate the training process of NiTi and improve the cyclical stability, researchers explore several methods to strengthen the NiTi alloy, reduce defect accumulation, including forming coherent or semi-coherent precipitation, increase geometric compatibility by adding a third element, refine grains to improve the strength of the material, etc., but these methods are difficult to achieve uniformity and stability, and even change the performance of the NiTi. For example, adding Cu element to NiTi improves lattice compatibility, and a thin film material is prepared to obtain a NiTiCu thin film with reduced hysteresis and stable circulation (Science, 348 (2015) 1004-1007). But the film preparation technology is difficult and the cost is high. Ni 4Ti3 semi-coherent precipitation is formed by low-temperature aging of the NiTi alloy for a long time, but overgrowth of Ni 4Ti3 precipitates is easily caused by excessively long aging time, and coarse grains are further caused, so that the functional stability of the NiTi alloy is reduced, and a certain degree of metal oxidation (MATERIALS CHARACTERIZATION 172 (2021) 110832) is difficult to avoid in a long-time processing process. Therefore, a simple and feasible nickel-titanium-based composite material capable of achieving high hardness and high cycle stability is needed to meet the use requirements. Disclosure of Invention In order to overcome the defects in the prior art, the invention provides a powder sintering preparation method of a nickel-titanium-based composite material, which specifically comprises the following