纳米Al_2O_3和NiAl共同强化的铁基ODS合金的铝热合成研究  

Al_2O_3 NANOPARTICLE AND Ni Al REINFORCED Fe-BASED ODS ALLOYS SYNTHESIZED BY THERMITE REACTION

作　　者：崔跃[1] 席文君[1] 王星[1] 李树杰[1] 

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100191

出　　处：《金属学报》2015年第7期791-798,共8页Acta Metallurgica Sinica

基　　金：国家自然科学基金资助项目51472015~~

摘　　要：采用铝热合成法制备了Al2O3和Ni Al共同增强的铁基氧化物弥散强化(oxide dispersion strengthened,ODS)合金,研究了Al2O3纳米粒子的大小、分布和运动行为.研究表明,添加Ti O2凝胶可以形成大小约为10 nm的Al2O3纳米粒子,这些Al2O3纳米粒子由于界面能的作用全部与Ni Al相结合.当添加Ti O2凝胶的质量分数达到1.24%时,合金的拉伸强度达到最大值849 MPa,并保持13%的延伸率.Fe- based oxide dispersion strengthened（ODS） alloys are widely used in advanced aircrafts and gas turbine engines due to their good high temperature strength, creep properties and hot-corrosion resistance. Traditionally, ODS alloys are prepared by internal oxidation and mechanical alloying. However, internal oxidation cannot be applied to multi- component alloys. It is difficult to guarantee other elements from being oxidized. On the other hand, the use of mechanical alloying will bring in impurities in the process of ball milling which will compromise the purification of alloy particles surface. In this work, Ti O2 xerogel prepared by using sol- gel method was added to the thermite powder mixture and the mixture was then ignited by using a tungsten filament. It solidified rapidly after the molten metal flowed into the bottom of the graphite mold because of the gravity field. It was found that Al2O3 and Ni Al were formed in situ in the molten metal. Therefore, Al2O3 nanoparticles and Ni Al reinforced Febased ODS alloy could be prepared by using this method. The phase composition and morphology of the Fe-based ODS alloy were investigated by using the combination of OM, SEM, TEM, XRD. The size of Al2O3 nanoparticles and the influence of Brownian motion and interface energy on the distribution and movement of the Al2O3 nanoparticles were investigated. The mechanical properties of the Fe-based ODS alloy with different contents of Ti O2 xerogel was investigated by using mechanical properties testing machine. The experimental results show that the Febased ODS alloy consists of ferrite a-Fe Ni Cr Al, Ni Al, and Al2O3 nanoparticles. The diameter of Al2O3 nanoparticles is approximately 10 nm. Both Brownian motion and interface energy affect the motion of Al2O3 nanoparticles during the solidification, however, interface energy is dominant. The interface energy between Al2O3 nanoparticles and Ni Al is lower than that of Al2O3 and ferrite a-Fe Ni Cr Al. Therefore, nearly all the Al2O3 nanoparticles are connected with the

关 键 词：纳米AL2O3 界面能 拉伸性能 氧化物弥散强化合金 

分 类 号：TG148[一般工业技术—材料科学与工程]