纳米Ni粉末的制备及相转变研究

The Preparation Methods and Phase Transformation Study of Nano-nickel Powder

利用柠檬酸盐分解法制备前驱体,在惰性气氛中进行热处理,合成了六角密排结构的纳米Ni粉末.并利用XRD、XRD高温测试手段对产物的相转变和结构变化过程进行了研究.结果表明,随着热处理温度的升高,纳米镍粉发生了六角密排到面心立方的结构相变,相变温度为350℃左右.此外,对转变后的面心立方相的镍粉进行进一步热处理,发现随着热处理温度的提高,晶粒尺寸和晶胞参数会逐渐增大.

By means of the citrate decomposition, we prepare precursor substance and sinter it at high temperature in inert atmosphere,then get nanonickel powder with hexagonal close packed structure. We use XRD,high temperature XRD analysis measurement to study the process of phase transformation and structural transformation. It was indicated that the structure of nano - nickel powder undergoes a transition from a hexagonal close packed phase to a face centered cubic phase with growth of temperature,the phase transformation point is about 350 ℃. Otherwise, we continue to sinter Ni powder which is facecentered cubic, finding that with growth of temperature, the crystal grain size and the lattice parameter increases.