机械合金化制备Ta-10%Al纳米晶过饱和固溶体

Nanocrystalline supersaturated solid solution Ta-10%Al prepared by mechanical alloying

利用机械合金化的方式制备了组成为Ta-10%Al（质量比）的纳米晶过饱和固溶体。以XRD和SEM为表征手段,研究了球磨时间对Ta-10%Al纳米晶过饱和固溶体产生的影响,并对Ta-10%Al纳米晶过饱和固溶体形成的热力学机理进行了研究。结果表明,随球磨时间增加,Al逐渐溶入Ta中。当球磨时间达到48 h后,Al完全固溶进Ta中形成Ta-10%Al纳米晶过饱和固溶体,晶粒尺寸和微观应力分别为84.3 nm和0.285%。延长球磨时间导致Ta-10%Al纳米晶过饱和固溶体晶粒细化且微观应力增加,过长的球磨时间可能引发合金粉末的团聚。以Miedema半经验模型为依据,建立了机械合金化过程中的热力学模型,计算结果显示,以机械合金化为手段制备Ta-10%Al纳米晶过饱和固溶体的主要驱动力来源于热力学驱动。

Nanocrystalline supersaturated solid solution Ta-10% Al（ mass percentage） was prepared by mechanical alloying method. The effect of milling time on the information of nanocrystalline supersaturated solid solution Ta-10% Al was investigated by using XRD and SEM,and the thermodynamic mechanism was explored. The results show that the dissolution of Al into Ta is enhanced with the increasing of ball milling time. When the ball milling time is 48 h,Ta-10% Al nanocrystalline can be identified,its grain size and micro-stress are 84. 3 nm and 0. 285%, respectively. Extending the ball milling time results in grain refinement and micro-stress addition of nanocrystalline supersaturated solid solution Ta-10% Al. The extension of the ball milling time could trigger the agglomeration,leading to the decrease of the particle sizes of Ta-10% Al. The thermodynamics model of Ta-Al system is established based on Miedema semi-experimental theory. The calculation result shows that the driving force of nanocrystalline supersaturated solid solution Ta-10% Al prepared by mechanical alloying comes from thermodynamics force.