Cu-Zr合金定向凝固组织的研究

The microstructure of Cu-Zr alloy by directional solidification

采用定向凝固方法制备了Cu 12 .2 5Zr自生复合材料,并通过扫描电镜(SEM)、透射电镜(TEM)和X射线衍射等方法对定向凝固组织进行了研究.结果表明,在温度梯度一定的前提下,生长速度对定向凝固组织的形貌有着重要的影响,随着生长速度的增加,凝固组织由层片状依次转化为棒状、树枝状和集群状组织;在所制备的Cu 12 .2 5Zr自生复合材料中,第2相主要是Cu5Zr,并且Cu5Zr与基体α(Cu)之间存在着一定的取向关系,另外还有少量的Cu8Zr3 相和Cu10 Zr7相;在Cu 12 .2 5Zr合金枝晶端部存在明显的Zr元素富集.

In-situ composite of Cu-12.25Zr alloy was prepared by directional solidification technique in this paper. And the microstructures of the composites were observed by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction. The results show that the effect of growth velocity on the microstructure of the composite is important under certain temperature gradient. With the increase of growth velocity, the shape of microstructure develops into laminate, bar and dendrite in turn. The main second phase in the composite is Cu 5Zr besides a little Cu 8Zr 3 and Cu 10 Zr 7, and the Cu 5Zr phase has certain orientation relationship to copper matrix. The enrichment of Zr element is also observed at the tip of the dendrites.