Effect of zirconia secondary peening on the microstructure and mechanical behavior of Al6061 cold spray coatings
Effect of zirconia secondary peening on the microstructure and mechanical behavior of Al6061 cold spray coatings
复制标题
DOI：
10.1016/j.surfcoat.2022.128269
复制
发表时间：
2022-02
影响因子：
5.4
通讯作者：
B. James;Venkata Satish Bhattiprolu;G. Crawford;B. Jasthi
中科院分区：
文献类型：
--
作者：
B. James;Venkata Satish Bhattiprolu;G. Crawford;B. Jasthi
冷喷涂技术通常用于修复金属部件，对原始部件的温度影响有限。然而，对于许多商业合金，例如Al 6061，通过使用低价氮气实现致密沉积物仍然具有挑战性。研究了二次喷丸对Al 6061冷喷涂层显微组织和力学性能的影响。以N2为载气，将平均尺寸为20 μ m的Al 6061球形粉末与~210 μm的氧化锆珠偶联沉积在Al 6061-T6基底上。涂层的显微组织和力学性能进行了比较，使用He和N2工艺气体产生的涂层。使用光学和扫描电子显微镜进行微观结构表征。与使用N2和N2与ZrO 2一起产生的涂层相比，用He工艺气体产生的涂层导致最低的孔隙率和更好的机械性能。与仅使用N2工艺气体产生的涂层相比，ZrO 2与N2工艺气体一起使用导致涂层的显微硬度增加约15%，结合强度增加约680%，孔隙率减少约28%，拉伸强度增加约34%。然而，使用N2和N2与ZrO 2耦合产生的涂层都表现出脆性行为，没有明显的延展性。即使有这种限制，使用ZrO 2作为二次喷丸介质可以为某些需要更高硬度和良好粘附强度的冷喷涂应用提供更便宜的替代品。
Cold spray technology is commonly used to repair metallic components with limited temperature influence on the original component. However, for many commercial alloys, such as Al6061, it is still challenging to achieve dense deposits by using low-priced nitrogen gas. The objective of this work was to investigate the effect of secondary peening with zirconia (ZrO2) ceramic beads on the microstructure and mechanical properties of the Al6061 cold spray coatings. Al6061 spherical powder with an average size of 20 μm coupled with zirconia beads of ~210 μm were deposited onto Al6061-T6 substrates using N2as the carrier gas. The microstructure and mechanical properties of coatings were compared with coatings produced using He and N2process gases. Microstructural characterization was performed using optical and scanning electron microscopy. Coatings produced with He process gas resulted in lowest porosity and with better mechanical properties compared to the coatings produced using N2and N2along with ZrO2. The use of ZrO2along with N2process gas resulted in ~15% increase in microhardness, ~680% increase in adhesion strength, ~28% reduction in porosity, and ~34% increase in tensile strengths in the coatings when compared with the coatings produced using N2process gas only. However, both coatings produced using N2and N2coupled with ZrO2exhibited brittle behavior with no appreciable ductility. Even with this limitation, using ZrO2as a secondary peening media could provide a cheaper alternative to using He gas for certain cold spray applications where a higher hardness and good adhesion strengths are needed.