采用铝热合成法制备了Al2O3和NiAl共同增强的铁基氧化物弥散强化合金（Oxide Dispersion Strengthened alloy）,研究了Al2O3纳米粒子的大小、分布和运动行为。研究表明，添加TiO2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NiAl相结合。当添加TiO2凝胶质量分数达到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 can not be applied to multi-component alloy. 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 purify of alloy particles surface. In this study, TiO2 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 NiAl were formed in-situ in the molten metal. Therefore Al2O3 nanoparticles and NiAl reinforced Fe-based ODS alloy can 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 TiO2 xerogel was investigated by using mechanical properties testing machine. The experimental results show that the Fe-based ODS alloy was consisted of ferrite α-FeNiCrAl, NiAl, and Al2O3 nanoparticles. The diameter of Al2O3 nanoparticles was 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 NiAl was lower than that between Al2O3 and ferrite α-FeNiCrAl. Therefore, nearly all the Al2O3 nanoparticles were connected with the NiAl phase. Higher TiO2 xerogel additions increased the tensile strengthen and elongation of the Fe-based ODS alloy. When the content of TiO2 xerogel was 1.24%, the tensile strength of the Fe-based ODS alloy attained 849MPa and the elongation was 13%. Continuing adding the TiO2 xerogel resulted in the release of large quantities of gas which produced holes in the Fe-based ODS alloy. These holes decreased the mechanical properties of the alloy.