15 results about "Niti alloy" patented technology

The application discloses a brazing filler metal for titanium alloy and stainless steel connection and application thereof, and the brazing filler metal comprises an Ag-Cu eutectic brazing filler metal base and NiTi alloy particles. By introducing the NiTi alloy particles into the Ag-Cu eutectic brazing filler metal base, the Ni and Ti in the interface neighborhood are cooperatively involved in diffusion and reaction, the wetting and forming consistency of the brazing filler metal are cooperatively improved, the interface reaction layer is formed into a discrete thin layer, the continuous brittle reaction layer is inhibited from being generated, the risk of crack propagation along the interface is reduced, the shear strength of the brazing filler metal welding joint for titanium alloy and stainless steel connection is remarkably improved, and the forming quality and batch consistency of the brazing joint are improved.

This invention discloses a method for preparing a DCPD / PEI / SiO2-CuS photothermal multifunctional film layer on the surface of an additively manufactured NiTi alloy, and the additively manufactured NiTi alloy prepared by this method, relating to the field of surface modification technology for medical materials. The method includes: depositing a DCPD film layer on the surface of an alloy substrate; ultrasonically mixing mesoporous SiO2 material in a mixed solution of anhydrous ethanol and deionized water, adding CuS powder for dispersion, centrifuging, washing, drying, and heat treatment to obtain a SiO2-CuS modified material; dissolving PEI in dimethylacetamide, uniformly dispersing the SiO2-CuS modified material therein to obtain an extraction solution; then immersing and pulling the NiTi alloy with the deposited DCPD film layer in the extraction solution to complete the coating of the photothermal multifunctional film layer on the NiTi alloy surface. This invention successfully improves the corrosion resistance and biocompatibility of the NiTi alloy substrate and endows its surface with highly efficient photothermal antibacterial properties.

This invention belongs to the field of composite material design and discloses a partition-wall NiTi composite material superstructure and its manufacturing method. The superstructure comprises a NiTi alloy superstructure support and a resin material filled within the support. The resin material is one or a composite of several of polyurethane resin, epoxy resin, polycarbonate, ethylene-vinyl acetate, and thermoplastic polyester elastomer. The NiTi alloy superstructure support consists of multiple vertically stacked chambers. Each chamber is composed of upper and lower partitions and an intermediate wall. Adjacent chambers share a partition, which is a solid thin-sheet structure. This invention proposes a new approach for directly synthesizing partition-wall NiTi composite material superstructures that possess high lightweight, excellent mechanical properties, high precision, and energy absorption performance, providing a technical foundation for the engineering application of multi-scale porous structures with impact resistance and energy absorption protection characteristics.

This invention discloses a high-martensite-content, pitting-resistant NiTi alloy and its laser powder bed melting preparation method and application, belonging to the technical fields of nickel-titanium shape memory alloys, additive manufacturing, and material corrosion protection. The method involves: under inert gas protection, LPBF forming is performed using a laser with a power of 180–220 W, a scanning speed of 1085–1325 mm / s, and a scanning spacing of 80–100 μm to form an austenitic structure with orientation characteristics; subsequently, a medium-temperature annealing treatment is performed at 500–550 °C for 180–240 min to induce the austenite to transform into martensite and inherit the orientation characteristics, achieving a martensite content of 42–55%, while simultaneously promoting the uniform distribution of nano-precipitates. The prepared alloy can effectively reduce electrochemical inhomogeneity, significantly improve pitting corrosion resistance in chlorine-containing environments, and has an overpassivation potential of 1300–1600 mV, exhibiting both good functional properties and promising engineering applications.

The invention relates to the technical field of biomedical materials, in particular to a preparation method of a hyperelastic low-modulus antibacterial bone implant, which comprises the following steps: firstly, designing a porous structure model with specific pore parameters based on a three-period minimal curved surface (Gyandroid), then uniformly mixing NiTi alloy powder with a small amount of Ag powder, and preparing a porous structure model; and finally, carrying out integrated forming by adopting optimized laser powder bed melting process parameters under a protective atmosphere. The prepared bone implant has the low elastic modulus of 1.5-3.5 GPa, can be well matched with human bones, and remarkably reduces the stress shielding effect; and meanwhile, the superelasticity of the NiTi alloy is reserved, and the alloy has the capability of recoverable deformation under the strain of 4%. Besides, by adding the Ag element, the antibacterial rates of the implant to staphylococcus aureus and escherichia coli exceed 90%, the material is endowed with excellent antibacterial performance on the premise of not excessively changing the matrix tissue, and the clinical safety and service reliability of the implant are effectively improved.

The present disclosure provides a method for regulating dynamic recrystallization of NiTi alloy by Ti2Ni phase, comprising: after open-die forging of the as-cast NiTi alloy, performing staged thermal mechanical treatment, first performing first-stage thermal deformation, then performing second-stage thermal deformation, and rapidly water cooling after deformation; by regulating the two-stage variable-temperature and variable-strain rate, Ti2Ni, which is originally considered as a harmful phase, is converted into a micro tool for controlling grain boundary migration; by using Ti2Ni to induce particle-induced nucleation in the low-temperature region, the critical strain required for complete recrystallization is reduced, and the limitation of traditional single thermal coupling driving is broken; this innovative mechanism not only promotes the occurrence of austenite grain dynamic recrystallization process by increasing nucleation sites, but also inhibits the organization coarsening caused by high-temperature grain boundary migration by using the pinning effect of the second phase particles, so as to realize the precise regulation of the uniformity of the organization under a lower deformation amount.

The application provides an isotropic NiTi alloy, a preparation method and application thereof. The preparation method of the NiTi alloy further comprises heat treatment on a blank, and the heat treatment comprises the following steps in sequence: solid solution treatment is performed on the blank at 670 DEG C to 720 DEG C for 5 min to 10 min, then first cooling is performed at a first cooling rate to obtain a solid solution product; the solid solution product is heated in a silicon oil medium at a heating rate of 3 DEG C / min to 5 DEG C / min, and aging treatment is performed at 100 DEG C to 300 DEG C for 12 h to 72 h, then second cooling is performed at a second cooling rate to obtain the isotropic NiTi alloy. Based on the two-stage heat treatment process of short-time low-temperature solid solution and silicon oil uniform-temperature aging, the homogenization of tensile properties of samples in different printing directions is realized, and the NiTi alloy component with high performance consistency is obtained.

The invention discloses a self-resetting damping device, and belongs to the technical field of damping devices. The supporting base of the self-resetting damping device comprises a bottom plate, a pair of force bearing check blocks and a pair of limiting blocks, the force bearing check blocks and the limiting blocks are welded to the bottom plate, and the limiting blocks are arranged between the force bearing check blocks; the SMA module comprises a pair of NiTi alloy bars and a force transmission sliding block, the pair of NiTi alloy bars are in threaded connection with the pair of force bearing check blocks through two nuts, and the force transmission sliding block is arranged on the bottom plate in a sliding mode; the pair of disc spring modules are correspondingly arranged on the pair of NiTi alloy bars in a sliding mode, each disc spring module comprises an anti-buckling steel pipe, a pre-pressing ring, a disc spring set, a locking nut and a U-shaped force transmission sleeve, the anti-buckling steel pipes are arranged on the NiTi alloy bars in a sliding and sleeving mode, and through the integrated design of the supporting base, the SMA modules and the disc spring modules, earthquake energy is dissipated through pulling and pressing hyperelastic deformation of the NiTi alloy bars; and the elastic restoring force of the disc spring group is combined to realize post-earthquake self-resetting.

Ternary and quaternary shape memory alloys, particularly nickel-titanium based quaternary and quaternary shape memory alloys, are disclosed and made by a method employing physical vapor deposition (PVD), such as by sputtering, of NiTiX, wherein X is a ternary metal constituent. By employing PVD processing, ternary and quaternary NiTi alloy bulk materials may be made in in the as-deposited state such that the configuration and conformation of a desired precursor material, e.g., wires, tubes, planar materials, curvilinear, or as the near finished end product, such as a hypotube for stent manufacture, semilunar for cardiac valves or conical for embolic or caval filters, is formed on a removable deposition substrate in the configuration and conformation of the precursor material or near-finished end product.

The application provides a method for inducing a high-hardness and high-wear-resistance gradient structure 60NiTi alloy by laser quenching, and relates to the technical field of high-nickel NiTi alloy processing. The application adopts laser quenching to perform surface treatment on a medium-temperature aging 60NiTi alloy, constructs a gradient structure, and mainly takes TiNi phase and Ni3Ti phase in the interior to maintain good superelasticity of the alloy to bear high stress overload impact, and mainly takes Ni4Ti3 phase and TiNi phase in the surface layer to obtain high hardness and high wear resistance, so that the surface superhard layer is obtained while the superelasticity is maintained, and the high wear resistance of the alloy surface layer and the high stress impact resistance of the alloy core are well combined.

This invention relates to a shape memory alloy-driven dual-mode thermal management film, composed of a three-layer asymmetric structure: a radiative cooling functional layer, a shape memory driving layer, and a solar energy absorption functional layer. The NiTi alloy sheet can reversibly flatten and roll up within a temperature range of 25℃–35℃, automatically switching between cooling and heating modes without external energy: at high temperatures, the radiative cooling layer faces outwards, with a reflectivity ≥0.94 and emissivity ≥0.95, resulting in a temperature drop of 5–15℃; at low temperatures, the solar energy absorption layer faces outwards, with an absorptivity ≥0.88 and emissivity ≤0.28, resulting in a temperature rise of 8–20℃. The total film thickness is <0.6 mm, allowing for roll production and installation via adhesive or magnetic bonding. It reduces HVAC energy consumption by 20–40% annually and is suitable for applications such as building roofs and agricultural greenhouses.

The present application relates to the technical field of powder injection molding material, and particularly relates to a Y-containing Ni-Ti based shape memory alloy and a molding process thereof, which comprises the following atomic mass percentage chemical components: Ti: 49.6-50.0%, Y: 0.2-0.6%; the balance is Ni and inevitable impurities; wherein, the chemical component Y is added in the form of Y powder in the shape memory alloy molding process, and is mixed with NiTi alloy powder by mechanical ball milling to form mixed powder, and then metal injection molding is performed. Compared with element Ti, Y has higher oxygen affinity, can reduce or eliminate the formation of TiO2, Ti4Ni2O x phases in the sintering process; the addition of Y reduces the consumption of Ti, ensures that the ratio of Ni and Ti is within a reasonable range, and the oxide formed by the Y element is within the micron range, which has little effect on the shape memory effect and mechanical properties of the NiTi alloy; the NiTi alloy component in the present application is suitable for powder metallurgy process, especially powder injection molding process (MIM).

This invention discloses a NiTi shape memory alloy with strong crystallographic texture and its preparation method, belonging to the field of NiTi shape memory alloys. The method includes: mounting nearly atomically equal NiTi polycrystalline rods in an electron beam levitation zone melting furnace, evacuating to a target vacuum level; increasing the filament current to a set current, and increasing the electron gun power until a molten zone appears and stabilizes; performing zone melting from bottom to top with the electron gun at a set zone melting rate; and cooling to room temperature after melting to obtain a polycrystalline NiTi shape memory alloy with a [001] orientation texture. This invention employs electron beam levitation zone melting technology, which is simple to operate, has high material utilization, and produces a NiTi alloy with high purity, strong texture, and excellent superelastic recovery performance.

The application discloses a surface treatment method for improving wear resistance of a metal matrix under oil-free lubrication, and compositely textured surfaces of the metal matrix are processed, wherein the compositely textured surfaces are composed of a plurality of hexagonal units arranged in a honeycomb shape, grooves are arranged between any adjacent hexagonal units, and a circular groove is arranged in the middle of each hexagonal unit; and a responsive multi-element composite solid lubricant is filled in the grooves and the circular groove between any adjacent hexagonal units; wherein the responsive multi-element composite solid lubricant is a composite of tin, carbon nanotubes, multi-element two-dimensional materials and NiTi alloy powder. The surface treatment method makes the metal matrix have excellent load-carrying capacity and self-lubricating performance under oil-free lubrication, and can solve the problem of high wear resistance of the existing metal matrix under oil-free lubrication.

Provided are a refrigeration material, a preparation method, and a cooler. The refrigeration material is NixTi100-x, x ranging from 50.6 to 58.0. The refrigeration material NixTi100-x comprises: austenitic (B2 phase) coarse grains and nano precipitates. A NiTi alloy rich in Ni (a Ni atomic percentage of 50.6% to 58.0%) containing the nano precipitates is used for refrigeration, wherein oversaturated Ni can effectively reduce the phase transition temperature and widen the lower limit of a superelastic temperature range, and the nano precipitates can strengthen the austenitic coarse grains (increasing the high-temperature yield strength) and increase the upper limit of the superelastic temperature range of the material, so that the alloy material can exhibit superelasticity at least in a temperature range from 203 K to 503 K (a total temperature span of 300 K). Due to large latent heat generated by the phase transition of the coarse grains of formula (I), a temperature change from 5 K to 33.6 K can be generated during adiabatic compression deformation, wherein temperature spans corresponding to adiabatic temperature drops of ≥10 K and ≥20 K can reach 200 K and 110 K, respectively. By using the NiTi refrigeration material having a wide temperature range, refrigeration and heating devices such as a refrigerator, an air conditioner, and a heat pump can be manufactured.