5results about How to "Good superelasticity" patented technology

The present invention relates to the technical field of functional property modification of high-temperature shape memory alloys, and in particular to a method for improving the superelasticity of NiTiHf high-temperature shape memory alloys. The method specifically comprises the following steps: sequentially subjecting NiTiHf high-temperature shape memory alloy ingots to homogenization treatment, rolling treatment, and electric pulse treatment. The present invention couples rolling with electric pulses and precisely controls parameters such as temperature, time, and frequency, thereby successfully achieving a NiTiHf high-temperature shape memory alloy with significantly improved superelastic properties without the need for severe plastic deformation treatment and long-term medium and high temperature heat treatment. Compared with the cast NiTiHf high-temperature shape memory alloy, in addition to significantly improving the superelastic properties, the elongation and tensile strength of the alloy are also greatly improved, wherein the recoverable strain increase is more than 200%, the elongation is increased by nearly 3 times, and the tensile strength is increased by more than 10%.

The invention discloses a method for improving the superelasticity of beta titanium alloy by preparing submicron grains, which comprises the following steps: firstly, obtaining a beta titanium alloy cast ingot by a vacuum argon arc melting method, and carrying out homogenization solution treatment on the beta titanium alloy cast ingot to ensure that a single beta phase structure is obtained; the method comprises the following steps: firstly, treating a beta titanium alloy ingot, then, carrying out large-deformation cold rolling treatment on the treated beta titanium alloy ingot with the cold rolling deformation being greater than 94%, and finally, carrying out low-temperature short-time solution treatment on the alloy plate subjected to large-deformation cold rolling treatment with the solution treatment temperature being 50-100 DEG C higher than the beta transformation temperature for 150-200s, so as to obtain the beta titanium alloy with submicron grains. According to the beta titanium alloy subjected to large-deformation cold rolling and low-temperature short-time solution treatment, the grain size reaches the submicron level, the minimum grain size is 0.3 micron, and the total recovery strain reaches up to 4.85%; according to the method, beta titanium alloy grains are refined to the submicron level through large-deformation cold rolling and low-temperature short-time solution treatment, so that the hyperelasticity of the beta titanium alloy grains is remarkably improved.

The invention relates to the field of TiNi-based shape memory alloy processing and preparation, in particular to a method for improving the superelasticity of a 4D printing TiNi-based shape memory alloy. The method comprises the steps that firstly, the 4D printing TiNi-based shape memory alloy is subjected to heat preservation for 1-3 h under the condition of 1000-1300 DEG C, then discharged out of a furnace and cooled to the room temperature in air, and the 4D printing TiNi-based shape memory alloy subjected to solution treatment is obtained; and the 4D printing TiNi-based shape memory alloy subjected to solution treatment is subjected to heat preservation for 0.5-200 h under the condition of 200-600 DEG C, then is discharged out of the furnace and is cooled to the room temperature, and the 4D printing TiNi-based shape memory alloy material subjected to solution aging treatment is obtained. According to the 4D printing TiNi-based shape memory alloy, the microstructure of the 4D printing TiNi-based alloy is adjusted through high-temperature solution treatment, so that the microstructure of the TiNi-based shape memory alloy is more uniform, a precipitated phase is promoted to be re-dissolved to form a supersaturated solid solution, then aging treatment is carried out, the precipitated phase is re-precipitated and uniformly distributed in a matrix, and the microstructure of the 4D printing TiNi-based shape memory alloy is obtained. And the hyperelastic performance of the 4D printing TiNi-based shape memory alloy is greatly improved.

The invention provides a one-way controllable sound field transducer of carbon nanotube sponge based on a magneto-thermo-acoustic coupling effect, and belongs to the technical field of transducers. Comprising a three-dimensional carbon nano-porous material serving as a main sound production element, strong magnets located on the two sides of the three-dimensional carbon nano-porous material, and an outer frame used for installing the strong magnets. The sound production element is composed of a piece of carbon nanotube sponge, metal electrodes located at the upper end and the lower end of the carbon nanotube sponge and aluminum oxide mirror surface ceramic insulating rods located at the left end and the right end of the carbon nanotube sponge, and electric signals are connected into the sound production element. According to the invention, thermal sound waves and magnetic sound waves are generated at the same time on the basis of a magnetic-thermal-sound coupling effect and are superposed into new sound waves, so that a wide and flat frequency response is achieved, the high-fidelity performance of the transducer is displayed, and crosstalk and loss of audio signals between traditional piezoelectric transducer elements are avoided; the energy conversion efficiency of the transducer can be improved, and the service life is prolonged.

This invention discloses a method for preparing monolithic SiC nanowire aerogels via in-situ carbothermal reduction, as well as the SiC nanowire aerogels prepared by this method and their applications, belonging to the field of advanced ceramic materials and aerogel preparation technology. This method uses biomass-derived cellulose fibers as the carbon source and three-dimensional template, silica nanoparticles as the silicon source, and NH4Cl as a volume shrinkage inhibitor. Through precursor preparation, freeze-drying, carbothermal reduction, and post-treatment steps, the controllable preparation of monolithic SiC nanowire aerogels is achieved. This invention features a simple, green, and economical process, is easily scalable, and allows for near-net-shape forming of complex shapes through mold design. The prepared aerogel has a three-dimensional interwoven nanowire network structure with a porosity as high as 99.7% and a thermal conductivity as low as 0.045 W / (m·K). It also exhibits excellent superelasticity, high-temperature stability, and high-efficiency oil absorption capacity, making it suitable for applications such as aerospace high-temperature insulation, energy system protection, and oil pollution treatment.