摘要
以工业级氯化铬、碳酸铵为原料,采用直接沉淀-常规干燥工艺制备出Cr(OH)3粉,并在200～600℃进行了煅烧试验,结果表明,Cr(OH)3粉在500～600℃煅烧后可转变成粒径在10～50nm之间、结晶较好、结构疏松的纳米Cr2O3粉。然后采用600℃煅烧后得到的纳米Cr2O3粉为原料,以100MPa的压力压制成20mm×15mm的试样,分别在1000℃、1100℃、1200℃、1300℃、1400℃和1500℃保温3h进行烧结试验,结果表明:试样在1000～1200℃煅烧后相对密度增大,但1200℃以后,煅烧后试样的相对密度反而下降;随着煅烧温度的提高,烧后试样中的Cr2O3微粒逐渐长大,且烧结体内部形成了内部中空的桥架结构。分析认为,由于纳米粉体内的团聚体存在大量的封闭大气孔,导致试样内部形成了桥架结构,影响了试样相对密度的增加。
The Cr（OH）3 powder was obtained by the liquid phase precipitation and conventional drying method using the raw materials .chromium chloride hexahydrat and salvolatile, and then the Cr（OH） 3 powder was calcined at 200-600 ℃. As a result,the nanometric chrome （Ⅲ） oxide powder was achieved with loose structure, better crystallization and particle size in the range from 10 to 50 nm after Cr（OH）3 powder calcined at 500- 600 ℃. Then the nanometer chromium sesquioxide powder which is obtained by calcining Cr（ OH）3 powder at 600 ℃ is pressed into column shaped specimens （Ф20 mm × 15 mm） under the pressure of 100 MPa. The sintering experiment is carried out when these specimens are calcined at the temperature of 1000 ℃;, 1100 ℃, 1200 ℃, 1300 ℃, 1400 ℃ and 1500 ℃ with 3 h of soaking time separately. The results showed that the relative density of the specimen increased after firing at the temperature of 1000 - 1200 ℃ but decreased after 1200 ℃;the particles are found to be grown up gradually and the bridge frame structures are formed inside the sintering body due to a large amount of closed pores inside of the congeries of nanosized powder, resulting in influence on increasing of the relative density.
出处
《耐火材料》
EI
CAS
北大核心
2006年第2期92-95,103,共5页
Refractories
关键词
纳米粒子
三氧化二铬
烧结
高铬耐火材料
Nanoparticles, Chromium sesquioxide, Sintering, High-chrome refractories
