ZnO多孔陶瓷的近净尺寸制备及机理  

Preparation and Mechanism of Near Net Size ZnO Porous Ceramics

作　　者：夏尊 戎烨东 李昊 董晔 于洪波[1] 王修慧[1] 杨金龙[1,2] XIA Zun;RONG Yedong;LI Hao;DONG Ye;YU Hongbo;WANG Xiuhui;YANG Jinlong(Key Lab of Preparation and Application of Inorganic Ultrafine Powder,Liaoning Provincial Department of Education,School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,Liaoning,China;State Key Lab of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]大连交通大学材料科学与工程学院,辽宁省教育厅无机超细粉体制备及应用重点实验室,辽宁大连116028 [2]清华大学材料学院,新型陶瓷与精细工艺国家重点实验室,北京100084

出　　处：《硅酸盐学报》2024年第9期2950-2958,共9页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(52072202)。

摘　　要：多孔陶瓷在烧结过程中会伴随着显著的收缩,导致变形或开裂,实现多孔陶瓷的近净尺寸制备是该领域新的发展方向。本研究以氧化锌与球形锌粉为原料采用干压成型工艺制备氧化锌多孔陶瓷,该过程不使用任何有机造孔剂,材料内部的气孔来自锌与氧之间的Kirkendall效应。由于锌、氧原子扩散速率的差异,锌颗粒氧化空心化产生的膨胀有效地抵消了整个烧结过程中产生的收缩,得到了近净尺寸的氧化锌多孔陶瓷。研究了金属锌粉的添加量以及颗粒尺寸对材料性能以及微观结构的影响。结果表明:多孔陶瓷的烧结线收缩率强烈依赖于金属锌粉的颗粒尺寸,当金属锌粉[50%(体积分数)]的颗粒尺寸为10μm时,多孔陶瓷的烧结线收缩率仅为-0.36%。Introduction During the sintering process,porous ceramics undergo significant shrinkage with volume changes even half.Such volumetric alterations may lead to materials cracking or deformation,severely affecting the yield of the prepared products.Researchers have proposed several methods such as adjusting the sintering temperature,utilizing reactions and expansion phases during the sintering process to address these issues.The most commonly method was to utilize the expansion characteristics of the materials themselves to solve the shrinkage problem.However,this method requires complex raw materials and lacks universality.Recently,our group proposed an in-situ hollow sphere method with the addition of spherical metal powders,successfully preparing porous ceramics without sintering shrinkage.The main theoretical support for this process is the Kirkendall effect that occurs during two-phase diffusion.When metal spherical particles are oxidized,the difference in diffusion rates forms a hollow structure,effectively offsetting the shrinkage caused by sintering.In this work,hollow zinc oxide particles were successfully prepared using the direct oxidation of metallic zinc powders and applied in the preparation of zinc oxide porous ceramics.During the oxidation process of metallic zinc powder,its addition amount,particle size,and their effects on the properties and microstructure of porous ceramics were investigated.The relationship between the pore size of porous ceramics and the particle size of metallic zinc particles was analyzed.This study could broad the application Scenarios of this process and hollow zinc oxide particles.Methods Firstly,zinc oxide powder and metallic zinc powder with different particle size were thoroughly ground and mixed in a grinding bowl according to a certain ratio(the volume percentage of metallic zinc powder to zinc oxide powder).Subsequently,a 5%PVA aqueous solution(50 g/L)was added to the total mass of powder as a binder,then stired further until the raw powders and binder were uniformly

关 键 词：多孔陶瓷 氧化锌 Kirkendall效应 氧化空心化 收缩率 

分 类 号：TQ174[化学工程—陶瓷工业]