(Ti,Zr,Hf)B_(2)粉体的制备及B4C含量对中熵陶瓷高温弯曲强度的影响  

Preparation of(Ti,Zr,Hf)B_(2) powders and effect of B4C content on the high temperature flexural strength of medium entropy ceramics

作　　者：高巍[1] 王新刚[2] 王小飞 徐京城[1] 王铭[2] 秦福林 李荣臻 蒋丹宇[2] GAO Wei;WANG Xin-Gang;WANG Xiao-Fei;XU Jing-Cheng;WANG Ming;QIN Fu-Lin;LI Rong-Zhen;JIANG Dan-Yu(School of Materials and Chemistry,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China)

机构地区：[1]上海理工大学材料与化学学院,上海200093 [2]中国科学院上海硅酸盐研究所无机材料分析测试中心,上海201899

出　　处：《现代技术陶瓷》2023年第4期342-351,共10页Advanced Ceramics

基　　金：国家自然科学基金(52172076)。

摘　　要：高熵陶瓷是陶瓷领域近几年的研究热点,过渡金属硼化物中熵、高熵陶瓷以其优异的性能、化学反应惰性和极高的熔点,成为耐极端环境的重要候选材料。本工作首次研究了B4C过量含量对中熵硼化物粉体合成、陶瓷致密化、微结构演变和高温弯曲强度的影响,确定了低氧含量、高烧结活性(Ti,Zr,Hf)B_(2)粉体的制备工艺。采用热压烧结工艺在1800℃制备的(Ti,Zr,Hf)B_(2)中熵陶瓷致密度高达99%以上。B4C过量15wt%的(Ti,Zr,Hf)B_(2)陶瓷晶粒尺寸为5.0±2.1μm,随着B4C过量含量增加到25wt%,晶粒尺寸明显细化至2.4±0.7μm。过量的B4C一部分与球磨引入的Si3N4原位反应生成BN相,另一部分B4C以第二相形式存在,BN和B4C相的引入可以有效抑制中熵陶瓷烧结过程中的晶粒生长,同时也提升了材料的高温弯曲强度。B4C过量25 wt%时,(Ti,Zr,Hf)B_(2)中熵陶瓷在1600℃具有优异高温弯曲强度,为631±62 MPa。High entropy ceramics are the research hotspot in recent years.Transition metal boride medium entropy and high entropy ceramics have become important candidate materials for extreme environment resistance,due to their excellent mechanical properties,chemical reaction inertia and high melting point.In this work,the effects of BC excess content on the densification,microstructure and high temperature flexural strength of medium entropy boride ceramics were studied for the first time,and the preparation process of(Ti,Zr,Hf)B_(2) powder with low oxygen content and high sintering activity was synthesized.The entropy ceramic density of(Ti,Zr,Hf)B_(2) prepared by hot pressed sintering method at 1800°C is over 99%,and the grain size of(Ti,Zr,Hf)B_(2) ceramics with excess content of 15 wt%B4C is 5.0+2.1μm.As the excess content of B4C increases to 25 wt%,the grain size is significantly refined to 2.4±0.7μm.The part of excess B4C reacts with SisN4 introduced by ball milling,to produce BN phase by in situ reaction,while the other part of B4C exists in the matrix as a second phase.The introduction of BN and BaC phases can effectively suppress grain growth during the sintering process of medium entropy ceramics,while also improving the high-temperature flexural strength of the ceramics.When B4C exceeds 25 wt%,the(Ti,Zr,Hf)B_(2) medium entropy ceramics have the highest high-temperature flexural strength at 1600 C of 631±62 MPa.

关 键 词：中熵陶瓷 硼化物陶瓷 高温弯曲强度 碳化硼 

分 类 号：TN384[电子电信—物理电子学]