文献类型：期刊文献

中文题名：基于分子动力学模拟的Fe_(2)O_(3)纳米颗粒烧结机制研究

英文题名：Study of the sintering mechanism of Fe_(2)O_(3) nanoparticles based on molecular dynamics simulation

作者：曾如宾[1,2];沈中杰[1,2];梁钦锋[1,2];许建良[1,2];代正华[1,2,3];刘海峰[1,2]

机构：[1]华东理工大学国家能源煤气化技术研发中心,上海200237;[2]华东理工大学上海市煤气化工程技术研究中心,上海200237;[3]新疆大学化工学院,新疆乌鲁木齐830046

年份：2023

卷号：74

期号：8

起止页码：3353

中文期刊名：化工学报

外文期刊名：CIESC Journal

收录：CSTPCD;;Scopus;北大核心:【北大核心2020】；CSCD:【CSCD2023_2024】；

基金：上海市浦江人才项目(21PJ1402300)。

语种：中文

中文关键词：Fe_(2)O_(3)纳米颗粒;空位缺陷;烧结机制;原子迁移;分子动力学模拟

外文关键词：Fe_(2)O_(3)nanoparticles;vacancy defects;sintering mechanism;atomic migration;molecular dynamics simulation

摘要：氧化铁是化工、冶金和能源等领域重要的原料,其在高温下的烧结性对产品性能至关重要。通过分子动力学模拟(MDS)研究了不同温度、粒径与空位缺陷浓度条件下Fe_(2)O_(3)纳米颗粒的烧结机制。结果表明,Fe_(2)O_(3)纳米颗粒粒径由3 nm增加至5 nm,烧结后收缩率由25.0%降低至10.8%,相对颈部宽度由96.6%降低至49.5%。当温度由900 K升高至1300 K,烧结过程原子扩散系数由1.758×10^(-3)nm^(2)/ps增至4.303×10^(-3)nm^(2)/ps,增大1.45倍。高温下(1300 K)原子迁移使颗粒部分结构由HCP和BCC结构转变为非晶结构,非晶原子比例为66.7%。含10.0%初始空位缺陷浓度纳米颗粒烧结过程的扩散活化能相比完美晶体(0空位浓度)降低约63.5%,原子迁移性及烧结致密化程度增强。研究结果对氧化铁颗粒高温热处理工艺优化具有指导意义。
Iron oxide is an important raw material in the fields of chemical industry,metallurgy and energy,and its sinterability at high temperature is crucial to product performance.In this study,the sintering mechanism of Fe_(2)O_(3)nanoparticles was investigated by molecular dynamics simulation(MDS)at different temperatures,particle sizes and vacancy defect concentrations.The results showed that when the particle size of Fe_(2)O_(3)nanoparticles increased from 3 nm to 5 nm,the post-sintering shrinkage decreased from 25.0%to 10.8%,and the relative neck width decreased from 96.6%to 49.5%.When the temperature was increased from 900 K to 1300 K,the atomic diffusion coefficient for the sintering process increased from 1.758×10^(-3)nm^(2)/ps to 4.303×10^(-3)nm^(2)/ps,which was increased to 2.45 times.Atomic migration at high temperature(1300 K)transformed some of the particle structures from HCP and BCC structures to amorphous structures with 66.7%of amorphous atoms.The diffusion activation energy of the sintering process of nanoparticles containing 10.0%initial vacancy defect concentration was reduced by about 63.5%compared with that of perfect crystals(0 vacancy concentration),and the atom mobility and sintering densification were enhanced.The above results are of great significance for the optimization of the high-temperature heat treatment process of iron oxide particles.