Preparation method of high density BaTi2O5 bulk

Abstract

The invention relates to a preparation method of high density BaTi2O5 ceramic bulk. The preparation method of high density BaTi2O5 ceramic bulk provided by the invention is characterized in that the method comprises the following steps: 1) placing BaTi2O5 raw material powders into a planetary high energy ball mill for grinding to obtain BaTi2O5 micropowders; 2) placing BaTi2O5 micropowders into agraphite mold, integrally moving into a discharge plasma sintering furnace, heating to the temperature of 980 DEG C-1100 DEG C in vacuum at a speed rate of 80-150 DEG C / min, insulating for 5-15 minutes, and applying the axial pressure of 30-60 MPa, then cooling to the room temperature with a furnace, obtaining a BaTi2O5 sintered body; 3) placing the BaTi2O5 sintered body into a box type electric furnace, heating to the temperature of 800 DEG C-1000 DEG C in air atmosphere at a speed rate of 2-10 DEG C / min, insulating for 12-24 hours, obtaining the BaTi2O5 ceramic bulk. The BaTi2O5 ceramic bulk prepared in the invention has the advantages of single phase, large size and high density (more than 95%) without doping any sintering addtitives, so that the invention has wide application prospect.

Description

technical field [0001] The invention relates to a highly dense BaTi 2 o 5 Method for preparing a ceramic block. Background technique [0002] Due to the excellent properties of dielectric, piezoelectric, ferroelectric, pyroelectric, photoelectric and nonlinear optics, ferroelectric materials show a wide range of application prospects, and their preparation, structure, performance and application have become the focus of current research on new materials. One of the hot spots. BaTi 2 o 5 It is a new type of lead-free ferroelectric material discovered in recent years, and its Curie temperature T c 475°C, higher than conventional BaTiO 3 The high temperature is about 340°C, and the dielectric constant along the b-axis direction is as high as 30000. It has the same characteristics as PbTiO 3 Comparable piezoelectric response characteristics, and green environmental protection. Therefore, BaTi 2 o 5 It is considered to be a new ferroelectric material with excellent perf...

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Problems solved by technology

[0003] In recent years, people have successively obtained BaTi by sol-gel, hydrothermal synthesis, quenching, zone melting and other methods. 2 o 5 Powders, strips, microspheres and single crystal blocks, etc., but the size of these products is very small (generally only a few microns to a few millimeters), which limits their further application

Although there are currently large-size (diameter> 10mm) BaTi 2 o 5 There are a few reports of ceramic blocks, but their density is low (<90%), which is difficult to meet the application requirements

For example, H. Beltrán et al. [1] Using atmospheric pressure sintering method, BaTi was obtained below 1200 °C 2 o 5 Ceramic block, but the existence of a large number of pores leads to its low density; G.J.Li [2] and J.Xu [3] et al by adding B 2 o 3 , ZrO 2 And KF and other sintering aids, can improve the BaTi to a certain extent 2 o 5 The sintered density of ceramics, but these admixtures have an adverse effect on product performance; R.Tu [4] prepared BaTi by hot-press sintering 2 o 5 Ceramic blocks, but limited by the particle size of raw materials, the density is still low

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