论文部分内容阅读
在真空气氛及氩气气氛中进行了 SmCo_5球体的烧结研究。在两种气氛内都可出现三个烧结阶段。在真空内由于扩散到表百上的钐的氧化作用,在两个相邻粒子间形成缩颈。在氩气气氛内蒸发及冷凝机制控制着缩颈的生长。由于沿晶界扩散的氧对钐的内氧化作用,在一定时间后缩颈的长大被阻止。此时烧结的第二阶段开始,在此阶段 SmCo_5球变为贫钐。在最后阶段,实质上是纯钴球体之间的缩颈直径更进一步增加。
Sintering of SmCo_5 spheres was carried out in a vacuum atmosphere and an argon atmosphere. Three sintering stages can occur in both atmospheres. A necking occurs between two adjacent particles due to the oxidation of samarium that diffuses into the gauge in vacuum. Evaporation and condensation in an argon atmosphere control the necking growth. As a result of the internal oxidation of samarium by the oxygen diffused along the grain boundaries, the growth of constrictions is prevented after a certain period of time. At this point the second phase of sintering starts, at this stage the SmCo 5 ball becomes samarium-deficient. In the final stage, the necking diameter between the substantially pure cobalt spheres is further increased.