摘要
热压注成型体积比为1:1的Mo-Al2O3金属陶瓷在空气中氧化始于500℃左右,生成MoO2,表现出增重;高于750℃时,由于生成的MoO3直接蒸发,明显失重。金属陶瓷中Al2O3含量越高,材料的抗氧化性能越好。在H2保护下金属陶瓷在钢渣中1650℃保温2h渣蚀时,由于材料中金属Mo被渣中FeO氧化后挥发,使得材料表层出现微小气孔,熔渣向材料中渗透,同时陶瓷晶粒从3～5μm增大到50～80μm。渣中的CaO与材料中陶瓷相Al2O3发生反应生成CA、C2A、C12A7等低熔点物质,使得材料性能进一步恶化,故该材料不宜在氧化性气氛或钢渣中长时间使用。
Mo-Al2O3 cermet specimens were fabricated by hot pressing casting. The oxidation of the cermets with a volume ratio of 1：1 began at about 500 ℃ in air, which formed MoO2 and showed continuous weight gain. However, weight loss was observed since the produced MoO3 was evaporated directly above 750 ℃. The higher content of Al2O3 in cermets was, the better the oxidation resistance of the materials. When the slag corrosion test was carried out in the metallurgical slag at 1650 ℃ for 2 h under the protection of H2, the molybdenum in the materials was oxidated by the FeO in the slag and volatilized, which resulted in the porosity appeared at the surface of cermets. Then the melting slag penetrated into the materials, meanwhile the grain size of the Al2O3 increased from 3-5 μm to 50-80 μm. The properties of the materials was deteriorated further due to the low melting matters such as CA, C2A and C12A7 formed by the reaction of CaO in the slag with Al2O3 in the cermets. Therefore, the cermets are not proper to use for a long time at oxidation atmosphere or in metallurgical slag.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第A01期238-240,共3页
Rare Metal Materials and Engineering
基金
国家自然基金委员会"重点基金"项目(50332010)
作者简介
刘开琪，男，1969年生，博士后，清华大学材料科学与工程系，北京100084，电话：010-62182491
