Zirconia ceramic plastic processing method assisted by direct-current electric field

Abstract

The invention discloses a zirconia ceramic plastic processing method assisted by a direct-current electric field. The method comprises the following steps: step 1, stabilizing ZrO2 powder by adoptingY2O3, and carrying out mold pressing and sintering to obtain a 3YSZ sample; step 2, heating the sample to 600-900 DEG C at a heating rate of 10 DEG C / min, and keeping the temperature for 30 minutes; and step 3, applying the direct-current electric field with current density of 50-400 mA / mm<2> to two ends of the sample under a temperature condition of 600-900 DEG C, keeping the direct-current electric field for 5 minutes, and then stretching the sample to complete the plastic processing. According to the invention, an electroplastic effect and an electrocaloric effect under the assistance of the direct-current electric field are utilized, so that deformation resistance in the plastic processing process is reduced while the deformation rate is increased and the environment temperature neededby the plastic processing is reduced, and the elongation rate of the plastic processing is improved.

Description

technical field [0001] The invention relates to the technical field of plastic processing of ceramic materials, in particular to a method for plastic processing of zirconia ceramics assisted by a direct current electric field. Background technique [0002] Zirconia (ZrO 2 ) is a ceramic material with high hardness, low thermal conductivity, high toughness, good wear resistance and high temperature ion conductivity; due to the unique properties of zirconia ceramics and their composites under different conditions ( Such as semiconductor, sensitive functionality and toughness); therefore, with the development of electronics and new material industries, zirconia ceramics are mainly used as refractory materials in the past; applications in electronic ceramics, functional ceramics and structural ceramics are developing rapidly However, the unique structure and chemical bond properties of zirconia ceramics determine that it is an inherently brittle material, and it is difficult to...

AI Technical Summary

Problems solved by technology

[0002] Zirconia (ZrO 2 ) is a ceramic material with high hardness, low thermal conductivity, high toughness, good wear resistance and high temperature ion conductivity; due to the unique properties of zirconia ceramics and their composites under different conditions ( Such as semiconductor, sensitive functionality and toughness); therefore, with the development of electronics and new material industries, zirconia ceramics are mainly used as refractory materials in the past; applications in electronic ceramics, functional ceramics and structural ceramics are developing rapidly However, the unique structure and chemical bond properties of zirconia ceramics determine that it is an inherently brittle material, and it is difficult to use traditional plastic processing methods to manufacture complex and large ceramic components, thus greatly limiting its application range

[0003] The current research on the plastic processing of zirconia ceramics is generally aimed at the plastic deformation of ultra-fine-grained zirconia ceramics at higher deformation temperatures and lower deformation rates; this is because the realization of superplasticity of zirconia ceramics requires a small grain size (usually 0.5T m (T m is the condition of melting point); for example, "The high temperaturemechanical characteristics of superplastic 3mol%yttria stabilized zirconia [J].Acta Materialia, 1998,46(2):667-679." describes the zirconia ceramics in a series of deformation rates, Deformation over a range of temperature and grain size with a maximum strain rate of 10 -4 the s -1 order of magnitude, the maximum elongation of the sample is only 65%; such a low strain rate and limited elongation are difficult to meet the industrial application requirements of plastic processing of zirconia ceramics; for example, "Microstructural examination in high-strain-rate superplastically deformed tetragonal ZrO 2 dispersed with 30vol%MgAl 2 o 4 spinel[J].Journal of Materials Research, 2007,22(03):801-813." It is mentioned that magnesium aluminum spinel doped zirconia composite ceramics can be used at a high temperature of 1500 ℃ and 10 -4 ~10 -1 the s -1 Deformation under the strain rate, the maximum elongation of the sample reaches 600%, but the disadvantage is that the formation of multiphase zirconia ceramics changes the single component of the zirconia material, which is not suitable for processing pure zirconia materials, so it is not universal. Secondly, due to the characteristics of the multi-phase structure, the structural deformation of spinel was observed in the deformed sample, and the pores were connected along the direction perpendicular to the loading, so the strength of the deformed material cannot be guaranteed; "Effect ofprestraining on cavity morphology in a superplastic 3mol% Yttria-stabilized tetragonal zirconia (3Y-TZP)[J]. Scripta Materialia,1998,39(1):119–124.”It is mentioned in 3YSZ ceramics at 1400℃ and 10 -3 the s -1 After reaching a pre-strain of 130% at a strain rate of 10 -4 the s -1 The strain rate can be deformed at a certain strain rate, which can reach 280% elongation; although the experiment proves that the introduction of pre-strain can effectively reduce the pores in the deformed sample and help to ensure the strength of the deformed material; but the introduction of pre-strain increases the plastic processing. process, which increases energy consumption, and the strain rate of secondary plastic processing is still very low, which is not conducive to the high efficiency of plastic processing

[0004] The existing plastic processing methods of zirconia ceramics often have the disadvantages of high deformation temperature, low deformation rate, high deformation resistance, low elongation, and greatly reduced material strength and changed material components after deformation, which are extremely limited. The application and development of zirconia ceramics

Images