节点文献
Mo-12Si-8.5B-xZr合金在1300℃下的抗氧化性能研究
Oxidation Resistance of Mo-12Si-8.5B-xZr Alloy at 1 300 ℃
【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Mo3Si和Mo5SiB2。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Mo2Zr和ZrO2颗粒。1 300℃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ZrSiO4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。
【Abstract】 The microstructure of Mo-12 Si-8. 5 B alloy exhibited that a continuous α-Mo matrix in which the Mo3Si and Mo5SiB2 particles were distributed dispersedly. After adding of 1 at% ~ 3 at% Zr to alloy,nano-scale Mo2Zr and ZrO2 particles were distributed at the grain interior and grain boundaries of alloy. At 1 300 ℃,Mo-12 Si-8. 5 B and Mo-12 Si-8. 5 B-1 Zr 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 ZrSiO4 particles formed in the oxide layer due to the excessive addition of Zr. Because of the difference of thermal expansion coefficient between the ZrSiO4 particles and the surrounding borosilicate glass,oxygen channels were easily formed at ZrSiO4/borosilicate interface.
【Key words】 Zr content; Mo-12Si-8.5B alloy; microstructure; oxidation resistance;
- 【文献出处】 中国钼业 ,China Molybdenum Industry , 编辑部邮箱 ,2021年06期
- 【分类号】TG146.412
- 【下载频次】36