论文部分内容阅读
研究了热处理过程中α-Fe_2O_3还原、Fe_3O_4氧化机理,考察了还原、氧化条件对γ-Fe_2O_3微观结构及磁性的影响。结果表明,还原温度和还原气空速是影响还原程度的重要参数。当还原温度为380℃、空速为1200h~(-1)时,所获磁粉矫顽力最高。Fe_3O_4烧结为表面扩散控制。Fe_3O_4向γ-Fe_2O_3的相变过程能加速粒子烧结。同时发现,当Fe_3O_4氧化不充分时,立方γ-Fe_2O_3中存在四方γ-Fe_2O_3杂相。
The mechanism of α-Fe_2O_3 reduction and Fe_3O_4 oxidation during heat treatment was studied. The effects of reduction and oxidation conditions on the microstructure and magnetic properties of γ-Fe_2O_3 were investigated. The results show that the reduction temperature and reducing gas space velocity are important parameters that affect the degree of reduction. When the reduction temperature is 380 ℃ and space velocity is 1200h ~ (-1), the coercivity of the obtained powder is the highest. Fe_3O_4 sintered surface diffusion control. The phase transition from Fe 3 O 4 to γ-Fe 2 O 3 accelerates the sintering of particles. It is also found that there is tetragonal γ-Fe_2O_3 heterophasic in cubic γ-Fe_2O_3 when the oxidation of Fe_3O_4 is not sufficient.