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干法、室温振动研磨制备铝超微颗粒,分别将研磨2h,4h和8h的铝粉,在常温下超声水解得到白色Al(OH)_3胶体,水解产品经干燥、研磨、焙烧后制备出多孔、片状γ-Al_2O_3纳米颗粒,粒度分布在30—50 nm之间.借助于X射线衍射(XRD)分析方法和透射电子显微镜(TEM),研究固体颗粒在细化过程中的能量转换,分析颗粒的微结构演化与机械力化学反应的关系,确定理想的研磨时间.研究结果表明:固体颗粒在机械力的作用下产生大量的应变和位错缺陷,使材料处于亚稳、高能活性状态,易于诱发机械力化学反应,在一定条件下晶体的表面能、应变能和层错能相互转化;研磨2 h的铝颗粒内部,晶格畸变和位错概率最大,材料显示出极高的化学反应活性,在超声波激发下,储存在材料内部的能量被充分释放,在较短的时间内,水解生成Al(OH)_3纳米颗粒.
Dry and grinding at room temperature to prepare ultrafine aluminum particles. The aluminum powders ground for 2h, 4h and 8h were respectively hydrolyzed at room temperature to obtain white Al (OH) 3 colloid. The hydrolyzed products were dried, ground and roasted to prepare porous , Flaky γ-Al 2 O 3 nanoparticles with particle size distribution in the range of 30-50 nm.The energy conversion of solid particles in the refining process was studied by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM) The relationship between the microstructure evolution of particles and the mechanochemical reaction and the determination of the ideal grinding time.The results show that the solid particles produce a large number of strain and dislocation defects under the action of mechanical force so that the material is in a metastable and energetic state, Easily induce mechanical and chemical reaction under certain conditions, the crystal surface energy, strain energy and stacking fault can transform into each other; grinding aluminum particles within 2 h, lattice distortion and dislocation probability of the largest, the material showed a very high chemical reaction Under the excitation of ultrasound, the energy stored inside the material is fully released and hydrolyzed to form Al (OH) 3 nanoparticles in a short period of time.