摘要
Mo-12Si-8.5B合金的微观组织表现为连续的α-Mo基体上弥散分布有Mo 3 Si和Mo 5 SiB 2。当在合金中添加1-3%(原子数分数,下同)Zr后,合金的晶内和晶界处形成了纳米Mo_(2) Zr和ZrO_(2)颗粒。1300℃下,Mo-12Si-8.5B和Mo-12Si-8.5B-1Zr合金表现出好的抗氧化性能,氧化后合金表面均形成了致密的硼硅玻璃保护层。Zr的添加促进了初始瞬态氧化阶段中硼硅玻璃相的流动,缩短了该阶段的持续时间。然而当Zr含量从2%增加到3%,合金的抗氧化性能逐渐下降。Zr的过量添加使得氧化层内形成了团聚的ZrSiO_(4)颗粒,这些颗粒由于与周边的硼硅玻璃相具有热膨胀系数的差异,在它们的界面处容易形成氧通道。
The microstructure of Mo-12Si-8.5B alloy exhibited that a continuousα-Mo matrix in which the Mo 3 Si and Mo 5 SiB 2 particles were distributed dispersedly.After adding of 1at%~3 at%Zr to alloy,nano-scale Mo_(2) Zr and ZrO_(2) particles were distributed at the grain interior and grain boundaries of alloy.At 1300℃,Mo-12Si-8.5B and Mo-12Si-8.5B-1Zr alloys exhibited good oxidation resistance.A dense and protective borosilicate scale was formed on the surface of alloys after oxidation.The addition of Zr promoted the flowing of borosilicate and shortened the duration time in the initial transient oxidation stage.However,with the increase of Zr content from 2 at%to 3 at%,the oxidation resistance of alloy decreased gradually.The aggregate ZrSiO_(4) particles formed in the oxide layer due to the excessive addition of Zr.Because of the difference of thermal expansion coefficient between the ZrSiO_(4) particles and the surrounding borosilicate glass,oxygen channels were easily formed at ZrSiO_(4)/borosilicate interface.
作者
李瑞
陈璇
王娟
李斌
张国君
LI Rui;CHEN Xuan;WANG Juan;LI Bin;ZHANG Guo-jun(Xi′an University of Technology,Xi′an 710048,Shaanxi,China)
出处
《中国钼业》
2021年第6期38-42,共5页
China Molybdenum Industry
基金
国家自然科学基金(52074219,51701162)
陕西省创新能力支撑计划(2019KJXX-071)。
