射频等离子体制备球形复合镍钛粉体

Synthesis of Ni-Ti composite powder by radio frequency plasma spheroidization process

以气雾化镍粉和不规则形状的钛粉作为原料,采用TEKNA射频等离子体设备制备宏观等原子比的球形复合镍钛粉末。研究载气流量对球化粉末的形貌、粒径、相分布和元素分布的影响。通过扫描电子显微镜和粒度分析仪表征粉体的形貌和粒径分布;通过XRD和EDS表征粉体的相以及元素分布。研究发现:与原料粉末相比,采用射频等离子体制备的复合粉末的粒径明显增大;载气流量增加会引起粉末镍元素质量分数的增加,在载气流量为2.5 L/min时,镍质量分数为55.2%,是最为接近理想的质量分数,球化率达到100%;球化粉末由Ni相、Ti相、NiTi相三相组成;各个粉末颗粒都能观察到Ni、Ti 2种元素,但各个颗粒中含有的钛、镍元素质量分数是不完全相同的。

Near-equiatomic Ni-Ti composite powder was synthesized by using gas atomized Ni powder and irregularly shaped Ti powder by TEKNA radio frequency plasma spheroidization process.The effect of carrier gas flow rate on the morphology,particle size,phase distribution and element distribution of the prepared powder was investigated.The morphology and particle size of the power were characterized by scanning electron microscopy and particle size analyzer while the phase constitution and element distribution were characterized by XRD and EDS.The results showed that compared with original powder,the prepared powder had a significant increase in particle size;as the carrier gas flow rate increased,so did Ni content of the powder.And when the carrier gas flow rate was 2.5 L/min,the spheroidization rate reached 100%and the Ni mass fraction was 55.2%;the spheroidized powder consisted of three phases,namely Ni phase,Ti phase and NiTi phase;Ni and Ti elements could be observed in each particle of the power,but the mass fraction of Ti and Ni contained in each particle was not completely the same.