在以电熔镁砂和鳞片石墨为主原料,热固性酚醛树脂为结合剂制备的MgO-C材料中,为了避免酚醛树脂炭化后产生的碳脆性大、石墨化难且抗氧化性差等不足,研究了单独添加2%(w)的球状Ni粉以及同时添加2%(w)的球状Ni粉和7.5%(w)的Al粉对MgO-C材料基质中次生碳显微结构的影响。结果表明:添加球状Ni粉的酚醛树脂炭化后有大量的碳晶须生成;仅添加球状Nj粉的MgO-C试样经不同温度热处理后,生成的物相均以碳微球的形式存在,随着热处理温度的升高,碳微球变化并不明显;同时添加Al粉和球状M粉的MgO-C试样经1000℃热处理后开始有碳晶须生成,碳晶须的直径约0.4~0.5μm,长度3~4μm,随着热处理温度的升高,碳晶须的生成量逐渐增加。
In order to tackle the shortcomings of high brittleness, hard graphitization,and poor oxidation re- sistance resulted from carbonization of phenolic resin of MgO-C refractories,effects of 2 mass% spherical Ni,and 2 mass% spherical Ni plus 7.5 mass% AI composite powder on microstructure of the secondary carbon in MgO-C refractories matrix were investigated. The results show that a large numbers of carbon whiskers form after the carbonization of phenolic resin with Ni powder;in the MgO-C refractories matrix with only Ni powder,the carbon microspheres form at all treatment temperatures and change slightly with temperature rising;the carbon whiskers begin to generate in the specimens with composite powder at :1 000 ℃,the diameter of carbon whiskers is about 0.4-0.5 μm ,and the length is about 3-4 μm ,and the formation amount of carbon whiskers increases gradually with temperature rising.