2results about How to "Reduce composition segregation" patented technology

This invention discloses a method for preparing high-entropy ceramic matrix composites using a reactive infiltration process, belonging to the technical field of ceramic matrix composites. The steps are as follows: at least four single-component carbides are ball-milled and mixed with a carbon source, then dispersed in a dispersion liquid to obtain a slurry; continuous fibers are woven into a preform, and an interface layer and a matrix layer are deposited to obtain a semi-dense composite material; the slurry is introduced through vacuum or pressure impregnation; and a high-entropy carbide matrix is ​​generated in situ and densified by reactive infiltration after embedding with a transition metal and its alloy. This invention solves the problems of long process cycles, high porosity, high cost, and insufficient introduction of high-entropy ceramics in existing processes, achieving rapid densification and improving the material's high-temperature stability, oxidation resistance, and ablation resistance. It is suitable for the large-scale production of thermal protection materials for hypersonic vehicles.

The invention relates to the technical field of aluminum alloy semi-solid processing, and provides a semi-solid slurry flow guide device for aluminum alloy, which comprises a shell, the bottom of the shell is fixedly connected with a rack, one end of the shell is fixedly connected with a feeding pipe, the other end of the shell is fixedly connected with a discharging pipe, and a material shifting mechanism is arranged at one end, close to the feeding pipe, of the inner side of the shell. The material stirring mechanism comprises two rotating plates which are arranged in parallel, a plurality of material stirring plates are fixedly connected between the two rotating plates, a plurality of electric heating pipes are arranged between every two adjacent material stirring plates, a first support is fixedly connected to the outer side of the rack, and a first motor is fixedly installed at the top of the first support; a flow guide mechanism is rotationally connected to the middle of the inner side of the shell, a filter screen is fixedly connected to the end, close to the discharging pipe, of the inner side of the shell, a stirring mechanism is arranged on one side of the filter screen, and a cleaning mechanism is arranged on the other side of the filter screen. Through the innovative mechanism design, the key problem in the aluminum alloy semi-solid slurry diversion process is solved.