11 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 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.

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.