Ceramic nano-crystallization method based on ultrafast laser remelting

Abstract

The invention relates to a ceramic nano-crystallization method based on ultrafast laser remelting. Accoring to the method, a ceramic surface is cleaned and then preheated, in an ultrafast laser radiation process, before a second pulse arrives, heat is rapidly diffused, under the action of original impurities or crystal nucleuses, molten local crystal grains are rapidly crystallized to achieve ceramic surface nano-crystallization, preheating is conducted after the ceramic surface is cleaned, and ultrafast laser radiation is conducted to achieve ceramic surface nano-crystallization. The method adopts ultrafast laser as an energy source, is safe and reliable, the nano-crystallization position is controllable, and the residual stress after nano-crystallization is small. The method is suitablefor functional ceramic products needing surface nano-crystallization treatment.

Description

technical field [0001] The invention relates to the technical field of ceramic surface nanocrystallization, in particular to a ceramic nanocrystallization method based on ultrafast laser remelting. Background technique [0002] In many high-power devices and large-scale equipment such as X-ray tubes, high-power klystrons, neutron beam diodes, pulse power switches, and accelerators, ceramic materials, as important electrical equipment for support and insulation, have excellent electrical and mechanical properties. , chemical properties are widely used, and play a very critical role in the performance and reliability of these devices. The traditional preparation method of ceramics is the high-temperature solid-state reaction method, which is also a method commonly used in the field of ceramic materials to prepare powders. However, the powder prepared by the high-temperature solid-state reaction method often has coarse particles, poor activity, and poor chemical uniformity. W...

AI Technical Summary

Problems solved by technology

For example, in the solid dielectric composite insulation system of high-voltage power equipment and high-power pulse devices, discharge and flashover along the solid surface will occur under a certain applied voltage, which seriously limits the overall performance of the insulation system. The grains of ceramic samples Affects its flashover voltage, the smaller the grain, the higher the flashover voltage, but the traditional sintered ceramics cannot realize complex structures due to the limitation of the mold, and the precision of the finished product is limited. The process is complex, so it is difficult to obtain stable surface mechanical and electrical properties

[0003] In view of the shortage of ceramic materials, micro-nano-sized particles are used to prepare functional ceramics. There are difficulties in the preparation of nano-sized ceramic particles, poor control of the porosity of the prepared ceramics, and poor mechanical properties.

However, adding an inoculant to increase the nucleation rate to control the grain size during the sintering process has disadvantages such as difficult process control.

Although the traditional heat treatment method can change the crystal phase of some ceramics, because of its high heating, it can only be processed as a whole at the same time, and cannot be used for local crystallization at key positions.

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