电铸Cu的显微组织、晶粒取向和晶界结构

采用SEM,TEM和EBSD研究了电铸Cu的微观组织形貌、晶粒取向和晶界特征.SEM观察表明,沿沉积方向,组织由细小等轴晶区、等轴晶和柱状晶的混合晶区转变为粗大柱状晶区.EBSD分析表明,对于所有晶区,小角度晶界(15°)的分布频率较小,大角度(≥15°)晶界为电铸Cu组织的主要晶界.在大角度晶界中,CSL晶界占有很大比例,其中Σ3的分布频率较大.柱状晶由平行分布的层状孪晶构成,近似垂直于沉积厚度方向,层间孪晶界为Σ3类型,TEM的观察也显示了孪晶的存在.细等轴晶区晶粒的择优取向不明显,混合晶区和粗柱状晶区有明显的〈111〉和〈101〉择优取向.在粗柱状晶区,平行于沉积厚度方向,具有较强的〈111〉择优取向,表明大多数{111}孪晶面垂直于沉积厚度方向.

A Study on the Grain Orientation and Grain Boundary of Electroformed Copper

The microstructure, grain orientation and grain boundary in electroformed copper prepared under specific conditions were studied using SEM, TEM and EBSD. SEM and TEM observations showed that the microstructure of electroformed copper along the thickness direction of deposition consists of fine equiaxed grains zone, mixture zone of equiaxed and columnar grains and large columnar grain zone. EBSD analysis indicates that distributing the ratio of low-angle grain boundary(＜15°)is lower and high-angle grain boundary (≥15°) is the dominating boundary in the electroformed copper. The high angle boundaries are mainly CSL and the ratio of ∑3 among CSL is relatively high. Columnar grains consist of parallel twin lamellar of which the normal is along the thickness direction. In the fine equiaxed grains zone, the preferred orientation of grains is not obvious. In mixture zone and large columnar grain