氧化预处理温度对Si粉流变性、水解及氮化反应的影响  

Effect of oxidation pretreatment temperature on rheology,hydrolysis and nitridation reaction of Si powder

作　　者：熊礼俊[1] 王刚[1] 郭鹏[1] 伍向红 

机构地区：[1]中钢集团洛阳耐火材料研究院有限公司先进耐火材料国家重点实验室,河南洛阳471039 [2]上海美路工程勘测有限公司,上海201906

出　　处：《耐火材料》2016年第6期436-439,共4页Refractories

摘　　要：在采用水基湿法浇注成型制备反应烧结Si3N4结合Si C材料时,为抑制Si粉原料的水解,首先将Si粉经600、700、800和850℃保温5 h氧化预处理,并与未处理Si粉一起分别制成水基浆料,研究了氧化预处理温度对Si粉在水中的流变性、水解反应的影响;然后将15%(w)的未处理或预氧化后的Si粉与85%(w)的Si C颗粒和细粉加水搅匀并浇注成型后,在氮化炉中经1 450℃保温3 h氮化烧成Si3N4结合Si C试样,研究氧化预处理温度对Si粉氮化反应的影响。研究表明:1)随着氧化预处理温度的升高,Si粉在不含分散剂的水基浆料中的黏度逐渐增大,在含有分散剂的浆料中黏度逐渐降低;2)氧化预处理温度越高,Si粉水解程度越弱;3)氧化预处理温度≤700℃时,对Si粉氮化反应影响不大;氧化预处理温度为800℃时,Si粉氮化反应受阻,试样中有残留硅存在。This work aimed at inhibiting the hydrolysis of Si powder during the synthesis of Si3N4 bonded SiC materials by reaction-sintering based on water-based casting moulding process. Si powder was oxidized at different temperatures （600,700,800 and 850 ℃） for 5 h. Then the untreated Si powder and the powders treated at different temperatures were made into aqueous slurries to study the effect of the oxidation pre- treatment temperature on the rheology and hydrolysis reaction of the Si powder in the water. Then 15 mass% untreated or treated Si powder,85 mass% SiC particles and fine powder,and water were mixed to prepare specimens by casting moulding. The green specimens were fired in a nitridizing furnace at 1450℃ for 3 h to prepare Si3N4 bonded SiC specimens to study the effect of oxidation pretreatment tem- perature on the nitridation reaction of the Si powder. The results show that with the increase of the oxidation pretreatment temperature, the viscosity of Si powder in the aqueous slurry without dispersant increases gradually, and the viscosity of Si powder in the slurry containing dispersant decreases gradually;the higher the oxidation pretreatment temperature,the less the hydrolysis degree of the Si powder;it has little effect on the nitridation reaction of the Si powder when the oxidation pretreatment temperature is less than 700 ~C;af- ter pretreatment at 800 ~C the nitridation reaction is blocked and residual silicon exists in the specimens.

关 键 词：SI粉 预氧化温度 流变性 水解 氮化反应 

分 类 号：TQ175[化学工程—硅酸盐工业]