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CN-121974365-A - Lithium disilicate crystal with nano-velvet branch structure and preparation method thereof

CN121974365ACN 121974365 ACN121974365 ACN 121974365ACN-121974365-A

Abstract

The invention discloses a lithium disilicate crystal with a nano-velvet branch structure and a preparation method thereof, belonging to the technical field of inorganic functional crystal materials. The preparation method comprises the steps of heating and melting lithium disilicate glass ceramic or a preparation raw material thereof, pouring the molten lithium disilicate glass ceramic or the preparation raw material thereof into a mold, cooling and solidifying the molten lithium disilicate glass ceramic to obtain original glass, performing primary crystallization treatment to obtain lithium disilicate glass ceramic with a specific microstructure, heating the lithium disilicate glass ceramic to partially melt the lithium disilicate glass ceramic to obtain lithium disilicate glass ceramic in a semi-molten state, performing speed-controlled cooling to realize secondary crystallization to obtain secondary crystallized lithium disilicate glass ceramic, and performing subsequent heat treatment to obtain the lithium disilicate glass ceramic. According to the invention, the preparation of the lithium disilicate crystal with the nano-velvet-whisker branched structure is realized by controlling the cooling process of the semi-molten glass ceramic, the mechanical property of the lithium disilicate crystal is obviously improved, the application scene is widened, and the problems of weak interface bonding, poor toughening effect and the like of the conventional lithium disilicate glass ceramic are solved.

Inventors

  • SUN JILONG
  • YU WEI
  • ZHANG HAIBAO
  • LI DING
  • ZHANG YAMING

Assignees

  • 陕西省交通运输工程质量监测鉴定站
  • 西安长智隧通科技有限公司
  • 西安邮电大学

Dates

Publication Date
20260505
Application Date
20260302

Claims (10)

  1. 1. The preparation method of the lithium disilicate crystal with the nano-velvet branch structure is characterized by comprising the following steps: s1, heating and melting lithium disilicate glass ceramic or a preparation raw material thereof, pouring the molten lithium disilicate glass ceramic or the preparation raw material thereof into a mold, and cooling and solidifying the molten lithium disilicate glass ceramic to obtain original glass; S2, performing primary crystallization treatment on the original glass obtained in the step S1 to obtain lithium disilicate glass ceramic with a specific microstructure; s3, heating the lithium disilicate glass ceramic with the specific microstructure obtained in the step S2 to enable the lithium disilicate glass ceramic to be partially melted, so as to obtain the lithium disilicate glass ceramic in a semi-molten state; s4, carrying out speed control cooling on the lithium disilicate glass ceramic in the semi-molten state obtained in the S3 to realize secondary crystallization, so as to obtain secondary crystallized lithium disilicate glass ceramic; s5, carrying out subsequent heat treatment on the secondary crystallized lithium disilicate glass ceramic obtained in the step S4 to obtain the lithium disilicate crystal with the nano-velvet branch structure.
  2. 2. The preparation method of the lithium disilicate crystal with the nano-whisker branched structure according to claim 1, wherein the lithium disilicate glass ceramic in the step S1 comprises recovered lithium disilicate glass ceramic scraps, and the preparation raw materials of the lithium disilicate glass ceramic comprise the following components ：67%≤SiO 2 ≤79%、10%≤Li 2 O≤14%、1%≤P 2 O 5 ≤5%、3%≤K 2 O≤5%、0＜Al 2 O 3 ≤4%、1%＜ZrO 2 ≤3.5% and 0< CeO 2 are less than or equal to 1.5% by weight.
  3. 3. The preparation method of the lithium disilicate crystal with the nano-whisker branched structure according to claim 2, wherein the recycled lithium disilicate glass ceramic leftover materials are subjected to sand blasting, acid etching and absolute ethyl alcohol cleaning treatment, and the preparation raw materials of the lithium disilicate glass ceramic are uniformly mixed by ball milling.
  4. 4. The method for preparing the lithium disilicate crystal with the nano-whisker branched structure according to claim 1, wherein the heating and melting conditions in the step S1 are that the temperature is raised to 1400-1500 ℃ at a temperature raising rate of 8-10 ℃ per minute, the temperature is kept at 1-3 h to obtain glass liquid, and then the temperature is continuously raised to 1520-1580 ℃ and the temperature is kept at 20-40 min.
  5. 5. The method for preparing lithium disilicate crystal having nano-whisker branched structure according to claim 1, wherein the primary crystallization treatment in S2 is performed under the conditions of heating to 600-630 ℃ at a heating rate of 30-40 ℃ per minute, maintaining the temperature at 30-90 min, then continuing heating to 843-900 ℃ and maintaining the temperature at 30-90 min.
  6. 6. The method for preparing lithium disilicate crystal having nano-whisker branched structure according to claim 1, wherein the heating treatment in S3 is performed under the conditions of heating to 910-930 ℃ at a heating rate of 40-60 ℃ per minute, and maintaining the temperature at 30-60 min.
  7. 7. The method for preparing lithium disilicate crystal having a nano-whisker branched structure according to claim 1, wherein the cooling rate of the controlled cooling in S4 is 1-5 ℃.
  8. 8. The method for preparing lithium disilicate crystal having a nano-whisker branched structure according to claim 1, wherein the subsequent heat treatment in S5 is performed under the conditions of heating to 790-890 ℃ at a heating rate of 10-40 ℃ per minute, and maintaining the temperature at 0-180 min.
  9. 9. A lithium disilicate crystal having a nano-whisker branched structure, characterized by being produced by the production method according to any one of claims 1 to 8.
  10. 10. Use of the lithium disilicate crystal having a nano-whisker branched structure according to claim 9 for the preparation of a coating material, a composite reinforcement phase or a biomedical material.

Description

Lithium disilicate crystal with nano-velvet branch structure and preparation method thereof Technical Field The invention relates to the technical field of inorganic functional crystal materials, in particular to a lithium disilicate crystal with a nano-velvet branch structure and a preparation method thereof. Background Lithium disilicate glass ceramics have excellent biocompatibility, excellent aesthetic properties and relatively high mechanical properties, and have been favored in recent years. However, the application of the lithium disilicate glass ceramic in the market at present is still relatively limited, and the lithium disilicate glass ceramic is mainly applied to dental products with relatively low requirements on mechanical properties, is more limited to dental restoration products with higher mechanical properties and other fields, and how to further improve the mechanical properties and other properties of the lithium disilicate glass ceramic and expand the application of the lithium disilicate glass ceramic in other fields is a key problem to be solved in the field of the lithium disilicate glass ceramic. The research on the improvement of the performance of the traditional lithium disilicate material focuses on a glass ceramic system, and the traditional rod-shaped crystal of the traditional lithium disilicate material improves the mechanical performance through a simple interlocking mechanism, but is limited by structural singleness, weak interface combination and high-temperature process bottleneck, and is difficult to play a role in reinforcing and toughening in a low-temperature cured coating. When the volume fraction of the crystal exceeds 30%, agglomeration is easy to occur, stress concentration defects are formed, and the breakthrough of performance bottlenecks through structural innovation is needed. Disclosure of Invention In order to solve the technical problems, the invention aims to provide the lithium disilicate crystal with the nano-velvet-whisker branched structure and the preparation method thereof, so as to solve the problems that the existing lithium disilicate glass ceramic has a single structure, weak interface bonding, difficulty in playing a role in strengthening and toughening in a low-temperature cured coating, easiness in agglomeration when the crystal volume fraction is high, stress concentration defects and the like. The technical scheme for solving the technical problems is as follows: in a first aspect of the present invention, there is provided a method for preparing lithium disilicate crystal having a nano-whisker branched structure, comprising the steps of: s1, heating and melting lithium disilicate glass ceramic or a preparation raw material thereof, pouring the molten lithium disilicate glass ceramic or the preparation raw material thereof into a mold, and cooling and solidifying the molten lithium disilicate glass ceramic to obtain original glass; S2, performing primary crystallization treatment on the original glass obtained in the step S1 to obtain lithium disilicate glass ceramic with a specific microstructure; s3, heating the lithium disilicate glass ceramic with the specific microstructure obtained in the step S2 to enable the lithium disilicate glass ceramic to be partially melted, so as to obtain the lithium disilicate glass ceramic in a semi-molten state; s4, carrying out speed control cooling on the lithium disilicate glass ceramic in the semi-molten state obtained in the S3 to realize secondary crystallization, so as to obtain secondary crystallized lithium disilicate glass ceramic; s5, carrying out subsequent heat treatment on the secondary crystallized lithium disilicate glass ceramic obtained in the step S4 to obtain the lithium disilicate crystal with the nano-velvet branch structure. The invention has the beneficial effects that nano velvet branches grow directionally on the surface of the micron-sized lithium disilicate main crystal through an innovative heat treatment path, and a multi-scale coupling structure is constructed. The process realizes secondary precipitation of crystals through semi-molten state temperature field regulation, controls the growth kinetics of the velvet whisker by utilizing the cooling rate, enables nanoscale branches and a trunk to form lattice continuous transition, and realizes the preparation of lithium disilicate crystals with a nano velvet whisker branch structure. The structure improves the interface contact area by 3-5 times, absorbs crack expansion energy through velvet deformation, reduces the addition amount of rigid particles, realizes the reinforcing and toughening synergistic effect of the coating material, and provides a brand new solution for the interface reinforcement of the coating, functional films and composite materials. Further, the lithium disilicate glass ceramic in S1 comprises recovered lithium disilicate glass ceramic scraps, and the preparation raw materials of the lithium disilicate g