论文部分内容阅读
利用铝矾土、轻质氧化镁粉,采用固相烧结工艺制备尖晶石质铸造砂。首先,研究球磨时间对原料粒径与表面形貌的影响;其次研究了烧结温度与保温时间对试样晶相组成、显微结构及物理性能的影响。结果表明:随着球磨时间的延长,原料发生二次细化与团聚,粉末形貌变化明显,球磨4 h与12 h均可将原料中位径降低至4μm;1450℃保温4 h烧结,得到发育完整清晰,外形呈八面体形貌,晶粒排列致密主晶相为MgAl2O4,体积密度约为3.0 g/cm3、显气孔约为3.3%;随着烧结温度的升高试样常温抗折强度得到提高,超过1500℃后变化不大。
The use of bauxite, light magnesium oxide powder, solid phase sintering process spinel foundry sand. Firstly, the effect of milling time on particle size and surface morphology was investigated. Secondly, the effects of sintering temperature and holding time on the phase composition, microstructure and physical properties of the samples were investigated. The results show that with the increase of ball milling time, the material is refined and agglomerated twice and the morphology of the powder changes obviously. The internal diameter of the material can be reduced to 4μm after 4 h and 12 h of milling, and sintered at 1450 ℃ for 4 h, The morphology is octahedron, the main grain phase is MgAl2O4, the bulk density is about 3.0 g / cm3, the apparent porosity is about 3.3%. With the increase of sintering temperature, the room temperature bending strength Get improved, little change after more than 1500 ℃.