【摘要】 研究分段反应烧结多孔Ni3Al金属间化合物在500~900℃空气中的氧化行为。结果表明,氧化温度越高,多孔Ni3Al的氧化质量增加越大;氧化温度为500℃时,氧化质量增加动力学行为符合抛物线规律,当氧化温度为700℃和900℃时,整个氧化过程分为氧化初期质量快速增加阶段和后期缓慢增加的平台阶段。多孔Ni3Al的高温氧化行为在外表面和孔隙内部同时发生,孔隙率高的样品氧化质量增加大。当氧化温度为700℃和900℃时,氧化主要发生在开孔的孔口附近,生成的氧化物可快速将样品表层的小孔封闭,阻止孔内的继续氧化。更多还原

【Abstract】 The oxidation behavior of step-sintered porous Ni3Al intermetallics with different open porosities was studied in air from 500 ℃ to 900 ℃.The oxidation mass of porous Ni3Al increases with the increase of oxidation temperature.The oxidation behavior of porous Ni3Al is presented by the parabolic law when the temperature is 500 ℃.Porous Ni3Al exhibited a rapid mass increase in the initial stage of oxidation and a slow mass increase in the following oxidation stage at the temperature of 700 ℃ and 900 ℃.The oxidation mass gain coexists in the pore channels and the surface of the porous Ni3Al,and the oxidation mass gain is proportional to the open porosity.The porosity leads to dominant internal oxidation mass gain in pore channels at the beginning of oxidation besides surface oxidation.The pores are blocked by the oxidation product rapidly at 700 ℃ and 900 ℃,leading to prevent the further oxidation of the inner pores.更多还原