Abstract: The disclosure discloses a polycrystalline diamond composite sheet having a continuous gradient transition layer and a 3D printing preparation method thereof. The polycrystalline diamond composite sheet consists of a polycrystalline diamond layer, a continuous gradient transition layer, and a cemented carbide substrate from top to bottom, in which the continuous gradient transition layer consists of diamond and cemented carbide. Along a direction from the cemented carbide substrate to the polycrystalline diamond layer, a content of the cemented carbide in the continuous gradient transition layer decreases from 100% to 0, and a content of the diamond increases from 0 to 100%. By designing and combining the continuous gradient transition layer with 3D printing technology, the disclosure realizes a continuous change in the two materials of diamond and cemented carbide, thereby eliminating the sudden change interface of the materials inside the diamond composite sheet.

Abstract: A silicon powder forming method, a silicon block, and a use thereof are provided, which relates to technical field of single crystal growth. The silicon powder forming method according to the present application includes: placing a mold filled silicon powder in a condition for first pressure P1 for a first pressure time T1 to obtain a silicon block, wherein the first pressure P1 and the first pressure time T1 satisfy: 50 MPa?P1?600 MPa, 7 min?T1?15 min. By pressure control, the molded silicon block is easily removed from the mold without crushing dust. The silicon block obtained is easy to crush upon charging, and the particle size distribution of the crushed silicon block is easy to control, resulting in raising less. The silicon block obtained can be directly used for production of Czochralski single crystal, and the charge density is increased to 0.18 g/cm3˜0.25 g/cm3.

Abstract: A silicon powder molding method, a silicon block, and their applications in the field of single crystal growth technology are provided. The silicon powder molding method of this application includes the following steps: placing a mold filled with silicon powder under a first pressure P1 condition, maintaining the first pressure condition P1 for a continuous duration of a first pressure time T1, and satisfying 50 MPa?P1?600 MPa, 7 minutes ?T1?15 minutes to obtain a silicon block. A medium applying the first pressure P1 is a liquid. Through pressure control, the molded silicon block is easily removed from the mold without breaking and generating dust. The silicon block is easy to crush when filling and has a controllable particle size distribution after crushing. The silicon block can be directly used for the production of Czochralski grown single crystals, increasing a loading density to 0.18 g/cm3˜0.25 g/cm3.

Abstract: A charging method of silicon material and a preparation method for single crystal are provided. The charging method includes: disposing the first material layer in the crucible; and disposing a second material layer on a side of the first material layer away from a bottom of the crucible, to cover the first material layer during vacuuming. The method for preparing a single crystal, using the silicon charging method described above. The preparation method for single crystal used the charging method for silicon material includes: covering a pot lid on the crucible to define a closed crucible body, and vacuuming the closed crucible body; lifting the closed crucible body into a single crystal furnace, and relieving pressure from the closed crucible body.

Abstract: The disclosure discloses a polycrystalline cubic boron nitride composite sheet having a continuous gradient structure and a preparation method thereof. The polycrystalline cubic boron nitride composite sheet consists of a cemented carbide substrate, a continuous gradient layer, and a CBN layer from bottom to top. The continuous gradient layer contains cemented carbide and CBN, a content of CBN increases in continuous gradient from bottom to top, while a content of the cemented carbide decreases in continuous gradient from bottom to top. A volume fraction D of CBN and a volume fraction M of cemented carbide in the continuous gradient layer both satisfy exponential gradient functions. At the same time, the disclosure uses direct ink writing 3D printing technology with slurry to realize the preparation of the polycrystalline cubic boron nitride composite sheet having the continuous gradient structure.

Abstract: A foldable electronic device includes a foldable apparatus and a flexible display. The foldable apparatus is configured to carry the flexible display, and includes a first housing, a second housing, and a foldable assembly. The foldable assembly includes a main shaft, a first fastening bracket, a first transmission member, a second fastening bracket, a second transmission member, and a stop block. Through movement of the foldable assembly, the first housing and the second housing are configured to be unfolded relative to each other to an opened state or folded relative to each other to a closed state.