Ni包裹Al_2O_3复合粉体的制备

Preparation of Nano-Ni-Coated-A1_2O_3 Composite Powder

采用非均相沉淀工艺在Ａｌ２Ｏ３颗粒表面均匀地包裹上镍盐前驱体，经煅烧、还原后得到纳米晶Ｎｉ包裹Ａｌ２Ｏ３复合粉体．相分析表明，非晶态的镍盐前驱体在５５０℃已转变为ＮｉＯ，再经７００℃氢气处理后，ＮｉＯ还原为Ｎｉ，其晶粒尺寸约为２０ｎｍ。结构分析表明，复合粉体在热处理过程中，包裹层由连续态变为非连续态．

Nano-Ni-coated-Al2O3 composite powder was prepared by the heterogeneous precipitation method. The amorphous NiCO3.2Ni(OH)(2)-2H(2)O was uniformly coated on the surfaces of Al2O3 particles. The amorphous coating layers were crystallized to NiO at 550degreesC for 2h in air. NiO was completely reduced to Ni at 700degreesC for 4h in hydrogen atmosphere. Ni with the size of about 20nm in the coating layers was spherical and weakly agglomerated. The continuous coated layers became discontinuous during heating treatment.