Xu Yiku, Huang Zhaohao, Chen Yongnan, Xiao Junxia, Hao Jianmin, Hou Xianghui, Liu Lin
School of Material Science and Engineering, Chang'an University, Xi'an 710064, China.
Faculty of Engineering, The University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Materials (Basel). 2020 Feb 19;13(4):911. doi: 10.3390/ma13040911.
In this work, a CuCe alloy was prepared using a directional solidification method at a series of withdrawal rates of 100, 25, 10, 8, and 5 μm/s. We found that the primary phase microstructure transforms from cellular crystals to cellular peritectic coupled growth and eventually, changes into dendrites as the withdrawal rate increases. The phase constituents in the directionally solidified samples were confirmed to be CuCe, CuCe, and CuCe + Ce eutectics. The primary dendrite spacing was significantly refined with an increasing withdrawal rate, resulting in higher compressive strength and strain. Moreover, the cellular peritectic coupled growth at 10 μm/s further strengthened the alloy, with its compressive property reaching the maximum value of 266 MPa. Directional solidification was proven to be an impactful method to enhance the mechanical properties and produce well-aligned in situ composites in peritectic systems.
在本工作中，采用定向凝固法在100、25、10、8和5μm/s的一系列拉拔速率下制备了CuCe合金。我们发现，随着拉拔速率的增加，初生相微观结构从胞状晶转变为胞状包晶耦合生长，最终变为枝晶。定向凝固样品中的相组成被确认为CuCe、CuCe和CuCe + Ce共晶。随着拉拔速率的增加，初生枝晶间距显著细化，从而导致更高的抗压强度和应变。此外，在10μm/s下的胞状包晶耦合生长进一步强化了合金，其压缩性能达到最大值266MPa。事实证明，定向凝固是一种增强力学性能并在包晶体系中制备取向良好的原位复合材料的有效方法。
