Zhang Hang, Chen Zihao, He Yaoyao, Guo Xin, Li Qingyu, Ji Shaokun, Zhao Yizhen, Li Dichen
State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Materials (Basel). 2021 Mar 30;14(7):1685. doi: 10.3390/ma14071685.
The conventional method of preparing metal-ceramic composite structures causes delamination and cracking defects due to differences in the composite structures' properties, such as the coefficient of thermal expansion between metal and ceramic materials. Laser-directed energy deposition (LDED) technology has a unique advantage in that the composition of the materials can be changed during the forming process. This technique can overcome existing problems by forming composite structures. In this study, a multilayer composite structure was prepared using LDED technology, and different materials were deposited with their own appropriate process parameters. A layer of AlO ceramic was deposited first, and then three layers of a NbMoTa multi-principal element alloy (MPEA) were deposited as a single composite structural unit. A specimen of the NbMoTa-AlO multilayer composite structure, composed of multiple composite structural units, was formed on the upper surface of a φ20 mm × 60 mm cylinder. The wear resistance was improved by 55% compared to the NbMoTa. The resistivity was 1.55 × 10 Ω × m in the parallel forming direction and 1.29 × 10 Ω × m in the vertical forming direction. A new, electrically anisotropic material was successfully obtained, and this study provides experimental methods and data for the preparation of smart materials and new sensors.
传统的制备金属-陶瓷复合结构的方法会由于复合结构的性能差异，如金属与陶瓷材料之间的热膨胀系数差异，而导致分层和开裂缺陷。激光定向能量沉积（LDED）技术具有独特优势，即材料成分在成型过程中可以改变。该技术能够通过形成复合结构来克服现有问题。在本研究中，采用LDED技术制备了多层复合结构，并根据各自合适的工艺参数沉积不同材料。首先沉积一层AlO陶瓷，然后作为单个复合结构单元沉积三层NbMoTa多主元合金（MPEA）。在一个φ20 mm×60 mm圆柱体的上表面形成了由多个复合结构单元组成的NbMoTa-AlO多层复合结构试样。与NbMoTa相比，耐磨性提高了55%。在平行成型方向的电阻率为1.55×10Ω×m，在垂直成型方向的电阻率为1.29×10Ω×m。成功获得了一种新型的电各向异性材料，本研究为智能材料和新型传感器的制备提供了实验方法和数据。
