SiO_(2)微粉加入量对β-SiAlON-SiC材料性能的影响

Influence of silica fume addition on properties of β-SiAlON-SiC material

在保证承烧锂电池三元正极材料匣钵用β-SiAlON-SiC材料抗碱性的前提下,以SiC颗粒和细粉、Si粉、Al粉、α-Al_(2)O_(3)微粉等为原料,采用高温氮化法制备β-SiAlON-SiC材料,研究了SiO_(2)微粉加入量(外加质量分数分别为0、1%、2%、3%)对β-SiAlON-SiC材料的显气孔率、体积密度、常温抗折强度、高温抗折强度、物相组成、抗碱性的影响。结果表明:1)在β-SiAlON-SiC材料中添加SiO_(2)微粉可以降低其显气孔率,显著提高其常温抗折强度和高温抗折强度;2)添加SiO_(2)微粉不会影响Si粉和Al粉的氮化效果,但会影响Al_(2)O_(3)在Si_(3)N_(4)中的固溶度和β-SiAlON的生成量;3)SiO_(2)微粉的最优添加量为1%(w),所得试样的抗碱性明显优于未添加SiO_(2)微粉试样的。

Under the premise of keeping good alkali resistance of β-SiAlON-SiC material used as saggers for firing ternary cathode materials of lithium batteries,β-SiAlON-SiC materials were prepared with SiC particles and fine powder,Si powder,Al powder and α-Al_(2)O_(3) micropowder as starting materials by the high temperature nitridation method.The influences of the silica fume addition(0,1%,2%,and 3%,extra adding,by mass) on the apparent porosity,the bulk density,the cold modulus of rupture,the hot modulus of rupture,the phase composition and the alkali resistance were researched.The results show that:(1)the silica fume addition reduces the apparent porosity,and increases the cold modulus of rupture and the hot modulus of rupture greatly;(2)the silica fume addition does not affect the nitridation of Si powder and Al powder,while impedes the solid solubility of Al_(2)O_(3) in Si_(3)N_(4) and the formation of β-SiAlON;(3)the optimal silica fume addition is 1% and the obtained sample has much better alkali resistance than that without silica fume.