( 1. 中南大學 冶金科學與工程學院，長沙 410083；
2. 中國鋁業(yè)股份有限公司 鄭州研究院, 鄭州 450041)
摘 要: 利用非均相沉淀包裹技術(shù)， 在室溫下的水溶液中， 以球形堿式碳酸鋁銨(AACH)、 硫酸鎳和碳酸氫銨為原料， 制備了金屬鎳包裹氧化鋁球形微粉前驅(qū)體， 即堿式碳酸鎳(NCH)包裹堿式碳酸鋁銨微粉。 然后， 將前驅(qū)體在500 ℃下用氫氣還原， 成功制備了表面光滑、 致密的金屬鎳包裹氧化鋁球形微粉。 研究了在非均相沉淀過程中， 被包裹堿式碳酸鋁銨微粉粉體濃度、 硫酸鎳和碳酸氫銨加料速度、 反應(yīng)時間、 表面活性劑等因素對復合粉體前驅(qū)體制備的影響， 利用SEM、 EDS、 XRD等手段表征了復合粉體前驅(qū)體及還原產(chǎn)物的表面及切面形貌、 成分和結(jié)構(gòu)。
關(guān)鍵字: 非均相沉淀； 包裹氧化鋁； 復合材料； 金屬鎳
（ 1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. Zhengzhou Research Institute of Chalco, Zhengzhou 450041, China）
Abstract: Nickel carbonate hydroxide(NCH)-coated spherical ammonium aluminum carbonate hydroxide(AACH) powders as the precursor of nickel-coated alumina spherical micrometer powders were prepared at room temperature by the aqueous heterogeneous precipitation method using nickel sulfate, ammonium bicarbonate solutions and spherical AACH powders as the major starting materials. The effects of the concentration of spherical AACH powders, rate of pumping nickel sulfate and ammonium bicarbonate solutions, reaction time, surface active reagent etc on coating of NCH on AACH were examined respectively. Uniform nickel-coated alumina micro-powders were successfully produced by reducing the as-prepared NCH-coated AACH precursors in H2 atmosphere at 500 ℃ for 2 h and the coating thickness of NCH or the resultant Ni thickness can be tailored by controlling the precipitating factors. The powders obtained were characterized by scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD).
Key words: heterogeneous precipitation; Ni-coated Al2O3; composite materials; Ni
