纳米Y-TZP材料烧结过程晶粒生长的分析

分析了无压烧结、热压烧结及SPS烧结过程中晶粒生长的行为及表现活化能．结果表明：在1100～1300℃之间，纳米Y-TZP材料在以上几种烧结条件下的晶粒生长行为不同．无压烧结时晶粒生长较慢，而热压烧结和SPS烧结时晶粒生长较快．对晶粒生长的活化能分析可在一定程度上解释以上现象．分析结果显示：无压烧结的表观活化能为281kJ／mol与纳米Y－TZP材料的晶界扩散活化能相近；热压烧结过程中，由于外压对扩散的促进作用，活化能比无压烧结时略有降低；在SPS烧结过程中，由于外加的脉冲电流能使晶粒表面大大活化，所以活化能与无压烧结相比大幅度下降．

Analysis of the Grain Growth of Nano Y-TZP Materials

The behavior and activation energy of the grain growth of the nano Y-TZP materials during pressureless sintering, hot-pressing and SPS were analyzed. It was found that from 1100℃ to 1300℃, the grain growth behaviour for the three sintering methods is different. When sintered by hot-pressing and SPS, the grain grows faster than that by pressureless sintering. These phenomena can be partly explained by the activation energy of the grain growth. The activation energy of the grain growth during pressureless sintering is about 300kJ/mol. During hot-pressing, the activation energy is less than that during pressureless sintering because of the promoting of the applied stress on the diffusion. During SPS processing, the surfaces of particles are activated by pulsed current, so the activation energy is significantly decreased.