Qu Shuo, Wang Liqiang, Ding Junhao, Lu Yang, Song Xu
Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong, China.
Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, China.
Materials (Basel). 2024 Dec 22;17(24):6270. doi: 10.3390/ma17246270.
Pure copper (Cu) is widely used across numerous industries owing to its exceptional thermal and electrical conductivity. Additive manufacturing has facilitated the rapid and cost-effective prototyping of Cu components. Laser powder bed fusion (LPBF) has demonstrated the capability to produce intricate Cu components. However, LPBF-fabricated components exhibit anisotropic features, which stem from their inherent thermal gradients, resulting in properties that depend on the grain orientation. In the present study, pure Cu samples were fabricated via micro-laser powder bed fusion (μLPBF), resulting in improved mechanical properties, specifically, enhanced strength and ductility. The as-printed pure Cu sample exhibited thermal stability owing to its high-density grain boundaries and dislocations, enabling it to maintain relatively high levels of strength and ductility even when exposed to an elevated temperature of 300 °C. Furthermore, the heat treatment resulted in the disappearance of the initial microstructural characteristics, such as molten pool boundaries. As the heat-treatment temperature increased, the anisotropic yield strength decreased. Overall, the anisotropy of the properties of pure Cu components fabricated via μLPBF can be mitigated through heat-treatment-induced microstructural adjustments.
纯铜（Cu）因其出色的热导率和电导率而在众多行业中得到广泛应用。增材制造促进了铜部件的快速且经济高效的原型制作。激光粉末床熔融（LPBF）已展现出制造复杂铜部件的能力。然而，LPBF制造的部件呈现出各向异性特征，这源于其固有的热梯度，导致性能取决于晶粒取向。在本研究中，通过微激光粉末床熔融（μLPBF）制备了纯铜样品，从而改善了机械性能，具体而言，提高了强度和延展性。打印后的纯铜样品由于其高密度的晶界和位错而表现出热稳定性，即使在暴露于300°C的高温下也能保持相对较高的强度和延展性水平。此外，热处理导致初始微观结构特征（如熔池边界）消失。随着热处理温度的升高，各向异性屈服强度降低。总体而言，通过热处理引起的微观结构调整，可以减轻通过μLPBF制造的纯铜部件性能的各向异性。
