纳米Al_2O_3和Cr_2O_3对镁铬材料烧结与力学性能的影响

Influences of nano-Al_2O_3 and nano-Cr_2O_3 on sintering and mechanical properties of magnesia-chrome refractories

利用纳米粉的粒径小及活性高等特性,在镁铬材料中加入不同质量分数(分别为2%、4%、6%)的纳米A l2O3或纳米Cr2O3粉体,研究了这两种纳米粉取代相应的微粉后对不同温度烧成的镁铬耐火材料烧结与力学性能的影响。结果表明:适量地用纳米粉体取代相应微粉可有效改善镁铬材料的烧结,提高其常温与高温力学性能,且烧成温度越低,纳米粉对镁铬材料性能的提高作用越明显;在本试验的镁铬材料的颗粒级配条件下,两种纳米粉的加入质量分数均以4%为最佳;纳米A l2O3的加入能降低镁铬质耐火材料的烧结温度,加入4%质量分数的纳米A l2O3可降低约100℃。

Different amounts （0,2% ,4% ,and 6% ） of nano-Al2O3 or nano-Cr2O3 powders were added to the magnesia-chrome refractories to replace the same amount of micro-Al2O3 or micro-Cr2O3 powders, respectively. The influences of the replacement on sintering and mechanical properties of magnesia-chrome refractories fired at different temperatures were studied. It is found that： （1）adding an appropriate amount of nano- powder can accelerate the sintering and improve mechanical properties of magnesia-chrome refractories at both ambient temperature and high temperatures; and the effect is more significant at the lower firing temperatures;（2）the appropriate additions of nano-Al2O3 or nano-Cr2O3 powders are both 4% based on the particle size composition of magnesia-chrome refractories of this experiment;（3 ）The firing temperature of magnesia-chrome refractories can be reduced by adding nano-Al2O3 powder, down 100℃ with 4% nano-Al2O3 powder addition.