氢气流量对超音速微粒沉积Al-12Si涂层的影响
第 24 卷第 6 期中国有色金属学报 2014 年 6 月 V olume 24 Number 6 The Chinese Journal of Nonferrous Metals June 2014 文章编号：1004-0609(2014)06-1504-06
氢气流量对超音速微粒沉积 Al-12Si 涂层的影响
朱 胜，刘玉项，王晓明，韩国峰，姚巨坤
(装甲兵工程学院 装备再制造技术国家重点实验室，北京 100072)
摘 要：采用 SEM、XRD、EDS、拉伸试验机及硬度仪，检测不同氢气流量下采用超音速微粒沉积技术制备的 Al-12Si 涂层形貌、相组成和力学性能，研究作为次燃料气和还原气的氢气流量对涂层结构和性能的影响。结果 表明：提高氢气流量能显著提高颗粒的速度，利于颗粒沉积；氢气流量为30 L/min时涂层最厚，但孔隙率最大；
继续增大氢气流量，厚度减小，孔隙率降低；涂层由α(Al)相和Al-Si共晶相组成，氧含量随氢气流量增大而降低， 未发现氧化物相；涂层结合强度超过 34 MPa，硬度是基体硬度的 2 倍以上，结合强度和硬度均随氢气流量增大 而增大，能够显著提升基体的耐磨性能。
关键词： Al-12Si涂层；氢气；超音速微粒沉积；流量；涂层性能
中图分类号：TG174 文献标志码：A
Effect of hydrogen flow rate on Al-12Si coating by
supersonic particles deposition
ZHU Sheng, LIU Yu-xiang, W ANG Xiao-ming, HAN Guo-feng, Y AO Ju-kun
(National Key Laboratory for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072, China)
Abstract: Adopting scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and tensile machine and hardness tester, the morphologies, phase constitutions and mechanical properties of Al-12Si coatings by supersonic particles deposition (SPD) at different hydrogen flow rates were detected, and the effect of the flow rate of hydrogen, which was treated as minor-fuel and reductive gas in the process of coating, on the structure and properties was studied. The results demonstrate that increasing the hydrogen flow rate can increase the velocity and deposition rate of the particles remarkably. The coating reaches the largest thickness and porosity when the hydrogen flow rate is 30 L/min, and the thickness and porosity tend to decrease with increasing hydrogen flow rate. The coating is composed of α(Al) phase and Al-Si eutectic phase, and the content of oxygen decreases with increasing the hydrogen flow rate, but oxidation phase is not discovered. The bonding strength is beyond 34 MPa, and the hardness of coating is twice more of substrate. The bonding strength and hardness increase with increasing the hydrogen flow rate, which can enhance the wear resistance of substrate notably.
Key words:Al-Si coating?H2? supersonic particles deposition?flow rate?coating properties
超音速微粒沉积技术 (Supersonic particles deposition) [1?3] 是在冷喷涂基础上发展起来的新型喷涂 技术。冷喷涂是基于空气动力学原理的喷涂技术，其 原理为在常温或较低温度下，利用高压气体(氮气、氩 气、 混合气体或空气等)携带粉末颗粒轴向进入缩放喷 嘴中，产生超音速气?固双相流，颗粒加速后(速度为 300~1200 m/s [4] )在完全固态下撞击基体，通过产生较 大的塑性变形沉积在基体上形成涂层 [5] 。超音速微粒 沉积技术与冷喷涂技术的不同在于工作气不仅有上述 冷喷涂的高压气体，还包括丙烷(C3H8)和氢气，二者
基金项目：国家自然科学基金资助项目(50975286)
收稿日期：2013-08-16；修订日期：2013-11-11
通信作者：朱 胜，教授，博士；电话：010-66717206；E-mail: zusg@https://www.wendangku.net/doc/934683852.html,