5 results about "Uniaxial pressure" patented technology

This invention discloses a rapid, high-strength microwave bonding method for ceramics and cemented carbide, belonging to the field of ceramic material bonding technology. The method includes the following steps: preparing a metal solder; grinding, polishing, and cleaning the bonding surfaces of the ceramic and cemented carbide respectively; loading the prepared metal solder into a mold and pressing it under uniaxial pressure to obtain a metal solder sheet; placing the ceramic, metal solder sheet, and cemented carbide in a stacked structure in a microwave sintering furnace for microwave sintering to achieve the bonding of the ceramic and cemented carbide. Compared with traditional brazing and diffusion welding, this ceramic-cemented carbide microwave bonding method increases the heating / cooling rate by 6-10 times, improves the single-furnace bonding efficiency by 5-9 times, allows for mass production, and yields ceramic-cemented carbide bonding interfaces with high strength. This invention significantly improves production efficiency, reduces energy consumption, and has widespread application value.

This invention relates to a transparent strontium fluoride ceramic based on low-temperature sintering, its preparation method, and its applications. The transparent strontium fluoride ceramic, by mass percentage, consists of 95-99% strontium fluoride matrix and 1%-5% thermosensitive luminescent material. The method of this invention uses a mild strontium acetate solution as a sintering aid, and successfully prepares a transparent strontium fluoride ceramic with a density greater than 99% and high optical transmittance under a low temperature of 100-150 °C and a uniaxial pressure of 300-400 MPa. The low-temperature sintering process of this invention avoids damage to the material from strong acids and alkalis, allows the thermosensitive luminescent material to be incorporated into the ceramic matrix during sintering, effectively preserving the excellent properties of the luminescent material and exhibiting excellent optical performance and encapsulation protection.

The application belongs to the technical field of ceramic low-temperature sintering, and particularly relates to a low-temperature preparation method of nano alpha-Al2O3 ceramic. The application adopts a cold sintering process, takes aluminum hydroxide powder as raw material, and takes 2-20 wt.% deionized water as solvent to obtain dense alpha-AlOOH ceramic under 500-2000 Mpa uniaxial pressure, 200-500 DEG C heating temperature and 50-300 min holding time; then, through a low-temperature annealing process, complete phase change from alpha-AlOOH to alpha-Al2O3 is realized under 400-600 DEG C annealing temperature and 2-6 h holding time, and finally alpha-Al2O3 ceramic sintered body with 30-50 nm grain size is obtained. The method overcomes the technical difficulty that traditional alpha-Al2O3 ceramic sintering temperature is high and it is difficult to obtain nano-crystal structure ceramic sintered body, and provides a process method for preparing alpha-Al2O3 ceramic with nano-crystal structure at low temperature, which has short preparation period and strong operability.

The application belongs to the technical field of rock mechanics test, and particularly relates to a biaxial compression clamping device based on arc turning, which comprises symmetrically arranged upper loading assemblies and lower loading assemblies, and each of the upper loading assemblies and the lower loading assemblies comprises a loading block, a force transmission block and a clamping block. The force transmission block is connected with the bottom surface of the loading block through a first rolling assembly, and the bottom of the force transmission block is provided with a circular arc surface. The clamping block is arranged below the force transmission block, the top of the clamping block is in sliding connection with the circular arc surface, the inner side of the clamping block is provided with a jaw for clamping a test piece, the inner side of the jaw is provided with an antifriction plate, and the antifriction plate is connected with the clamping block through a second rolling assembly. Through the cooperative action of the upper loading assemblies and the lower loading assemblies, the device can apply bidirectional adjustable compression load to the test piece under the driving of uniaxial pressure, not only can the uniaxial testing machine simulate complex biaxial stress state, but also can effectively isolate the interference of test piece deformation on the load transmission path through multi-stage rolling antifriction.