Al、Cu二元合金系烧结过程的原位观察

In-situ Observation on Sintering Process of Al-Cu Alloy

利用高温光学显微镜(HTOM)对由纯铝粉和纯铜粉制得的二元粉末体系进行了原位烧结试验,原位观察结果表明:经典烧结理论对塑性粉末体系不再适用;该体系烧结的典型物理过程可概括为颗粒边界熔化、晶界熔化、颗粒熔化,最后为合金元素铜的扩散均匀化,而这四个阶段在时间上并不能严格分开,而是交叠进行的;边界熔化受颗粒表面氧化膜破碎、表面曲率和颗粒变形等因素影响;晶界扩散在烧结过程中始终起着非常重要的作用。这些结果为进一步合理制定和优化烧结工艺提供了直接的参照依据。

The sintering process of Al-10Cu alloy was in-situ investigated using a high temperature optical microscope （HTOM）. The results show that the sintering process of the alloy can＇t be suited by the evolution of sintering neck any more, but can be described by the following stages： particle boundary melting, grain boundary melting, particle melting and alloy element homogenizing. The four stages can＇t be separated from each other, but overlapped partly. And the melting is affected by the crushing degree of the oxide film on the surface of metal particle, the curvature radius of particle surface and particle deforming. Grain boundary diffusion plays an important role in the whole sintering course. These results are very useful to establish properly and optimize sintering procedure.