过量Ti对TiB_(2p)/Fe-Cr复合材料组织和高温氧化行为的影响  

Effects of Excessive Ti on Microstructure and High-temperature Oxidation Behaviors of TiB_(2p)/Fe-Cr Composite

作　　者：黄沥 黄兴民[1,2] 罗康铭 巫佳伟 戴光泽[2] Huang Li;Huang Xingmin;Luo Kangming;Wu Jiawei;Dai Guangze(School of Materials Science and Technology,Southwest Jiaotong University;Key Laboratory of Advanced Materials of Ministry of Education,Southwest Jiaotong University)

机构地区：[1]西南交通大学材料科学与工程学院,成都610031 [2]西南交通大学先进材料教育部重点实验室

出　　处：《特种铸造及有色合金》2022年第7期832-837,共6页Special Casting & Nonferrous Alloys

基　　金：四川省科技计划资助项目(2020YFH0102)

摘　　要：采用原位自生法制备了TiB_(2p)增强Fe-Cr基复合材料,用X射线衍射(XRD)、扫描电镜(SEM)和能谱仪(EDS)等方法对比分析了两种TiB_(2p)/Fe-Cr基复合材料的显微组织和高温氧化行为。结果表明,过量Ti (6%)添加能有效地消除(Fe, Cr)_(2)B中间相,使TiB_(2p)形态从花瓣状转变为规则的多边形,显微硬度(HV_(0.5))从400大幅提升至860,断裂韧度从2.91 MPa·m^(1/2)提升至5.47 MPa·m^(1/2)。但是,粗大初生TiB_(2p)与基体的界面提供了氧扩散通道,表面氧化层由双层结构(金红石型TiO_(2)外层+Cr_(2)O_(3)过渡层)转变成三层结构(金红石型TiO_(2)外层+Cr_(2)O_(3)过渡层+TiO_(2)内层),导致900℃下抗氧化性能显著下降,氧化量增益率提升了307.4%。The TiB_(2p) reinforced Fe-Cr matrix composites were prepared by in-situ synthesis method. The microstructure and high temperature oxidation behavior of both the composites were analyzed by X-ray diffraction(XRD), scanning electron microscopy(SEM) and energy dispersive spectrometer(EDS). The results indicate that excessive Ti(6%) can effectively eliminate(Fe, Cr)_(2)B mesophases, and the morphology of TiB_(2) particles is converted from petal to regular polygon, where the microhardness is increased greatly from 400 HV_(0.5)to 860 HV_(0.5), and the fracture toughness is enhanced from 2.91 MPa·m^(1/2)to 5.47 MPa·m^(1/2). However, the interface between coarse primary TiB_(2)particles and matrix provide oxygen diffusion channel and the original two-layer structure of oxide layer(rutile TiO_(2) outer layer+compact Cr_(2)O_(3)inner layer) is transformed into three-layer structure(rutile TiO_(2) outer layer+compact Cr_(2)O_(3) transition layer+TiO_(2) inner layer), resulting in a significant decrease in oxidation resistance at 900 ℃, where the oxidation gain rate is increased by 307.4%.

关 键 词：颗粒增强复合材料 TiB_(2) 原位合成 高温氧化行为 

分 类 号：TB333[一般工业技术—材料科学与工程]