摘要
采用Mo/Al/B单质混合粉末为原料,进行放电等离子体烧结(SPS)以制备MoAlB材料。采用XRD和SEM等技术研究了产物的物相组成以及显微形貌。结果表明,以1Mo/1.1Al/1B粉末为原料,在900℃进行烧结,会诱发燃烧反应,生成MoAlB、MoB、Al_(8)Mo_(3)等构成的样品。产物中存在较多不规则的、几十微米尺度的气孔。晶粒非常细小,约为亚微米级别。此外有少量的晶须形成。提高烧结温度会促进MoB、Al_(8)Mo_(3)等转变为MoAlB材料。同时促进烧结致密化,MoAlB晶粒发育成板条状的细小晶粒。优化原料配比(1Mo/1.2Al/1.05B)和烧结制度(1150℃,保温5 min)会得到单相的、致密(相对密度为98%)的MoAlB材料。提出一个SPS诱发燃烧反应制备MoAlB的反应机制。首先,当温度升高到Al的熔点以上时,形成Al液相。然后,Mo首先与Al发生化学反应,生成富Al的AlMoX相。反应放出的热量较少,需要在SPS的加热辅助作用下,会诱发燃烧反应的发生。大量的Mo与B也会发生化学反应生成MoB。最后,Al_(8)Mo_(3),MoB与B等反应生成MoAlB。
MoAlB material is prepared by spark plasma sintering with Mo/Al/B mixed powder as raw material.The phase composition and microstructure of the product are studied by XRD and SEM.The results show that combustion reaction can be occurred in the 1Mo/1.1Al/1B powders at 900℃by spark plasma sintering.The sample composes of MoAlB,MoB and Al_(8)Mo_(3).There are many irregular pores with tens of microns in this product.The grains are very fine with a size of submicron.In addition,a small amount of whiskers is formed.Increasing the sintering temperature will promote the transformation of MoB and Al_(8)Mo_(3) into MoAlB materials.At the same time,its sintering densification is promoted,and the MoAlB grains develop into plate-like fine grains.By optimizing the raw material ratio(1Mo/1.2Al/1.05B)and sintering system(1150℃,holding for 5 min),a single-phase and dense(relative density of 98%)MoAlB material may be obtained.A reaction mechanism for preparing MoAlB by SPS induced combustion reaction is proposed.First,when the temperature rises above the melting point of Al,the liquid phase of Al is formed.Then,Mo first reacts with Al to form Al rich AlMox phase.The reaction will release less heat,and the combustion reaction will be induced under the heating effect of SPS.A large amount of Mo and B will also react chemically to form MoB.Finally,MoB and Al_(8)Mo_(3) react with B to form MoAlB.
作者
杜倩
高冀芸
郭胜惠
史书浩
梁宝岩
杨黎
DU Qian;GAO Jiyun;GUO Shenghui;SHI Shuhao;LIANG Baoyan;YANG Li(School of Metallurgy and Energy Engineering, Kunming University of Science and Technology,Kunming 650031, China;School of Materials And Chemical Engineering, Zhongyuan University of Technology,Zhengzhou 450007, China)
出处
《功能材料》
CAS
CSCD
北大核心
2022年第5期5112-5116,共5页
Journal of Functional Materials
基金
国家自然科学基金项目(51864028)
国家自然科学基金NSAF联合重点项目(U2030207)
云南省稀贵金属材料基因工程重大科技专项(202002AB080001)
云南省杰出青年基金项目(2019FJ005)。
