Corrosion Performance of Laser Posttreated Cold Sprayed Titanium Coatings
Corrosion Performance of Laser Posttreated Cold Sprayed Titanium Coatings
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DOI：
10.1007/s11666-011-9637-x
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发表时间：
2011-06-01
影响因子：
3.1
通讯作者：
Shipway, P. H.
中科院分区：
文献类型：
--
作者：
Marrocco, T.;Hussain, T.;Shipway, P. H.
最近冷喷涂技术的发展使得沉积高活性、氧敏感的材料（如钛）成为可能，而不需要粉末发生明显的化学反应，不需要改变颗粒的微观结构，也不需要对衬底加热。然而，沉积层内部相互连接的通道（微孔隙）的存在限制了金属涂层作为有效屏障的性能，而腐蚀介质对基体的侵蚀通常是不可避免的。本研究的目的是研究加工，包括后喷涂激光处理，对沉积组织和腐蚀行为的影响。使用商用冷喷涂系统(CGT（TM) Kinetiks(a (R)) 4000）将商业纯钛（CP Ti）沉积在碳钢基体上，其中预热的氮气作为主要工艺气体和粉末载气。使用商用2kw CO2激光器（505 Trumpf DMD）对选定的涂层进行表面熔化处理。从孔隙结构演变和微观组织变化两方面分析了沉积后激光处理对腐蚀行为的影响。采用光学显微镜、扫描电镜和x射线衍射对涂层的微观组织特征进行了研究。用电化学方法在3.5 wt.% NaCl中研究了它们的腐蚀性能（ASTM G5-94(2004)）。在加气NaCl溶液中，喷涂态钛涂层不能对碳钢基体提供良好的保护，而表面经过激光处理的涂层具有类似屏障的性能。
The recent development of cold spray technology has made possible the deposition of highly reactive, oxygen sensitive materials, such as titanium, without significant chemical reaction of the powder, modification of particle microstructure and with minimal heating of the substrate. However, the presence of interconnected pathways (microscale porosity) within the deposit limits the performance of the metallic coating as an effective barrier to corrosion and substrate attack by corrosive media is usually inevitable. The aim of the present study was to investigate the effects of processing, including a postspray laser treatment, on the deposit microstructure and corrosion behavior. Commercially pure titanium (CP Ti) was deposited onto a carbon steel substrate, using a commercial cold spray system (CGT(TM) Kinetiks(A (R)) 4000) with preheated nitrogen as both the main process gas and the powder carrier gas. Selected coatings were given a surface melting treatment using a commercial 2 kW CO2 laser (505 Trumpf DMD). The effect of postdeposition laser treatment on corrosion behavior was analyzed in terms of pore structure evolution and microstructural changes. Optical microscopy, scanning electron microscopy, and x-ray diffraction were employed to examine the microstructural characteristics of the coatings. Their corrosion performance was investigated using electrochemical methods in 3.5 wt.% NaCl (ASTM G5-94 (2004)). As-sprayed titanium coatings could not provide favorable protection to the carbon steel substrate in the aerated NaCl solution, whereas the coatings with laser-treated surfaces provided barrier-like properties.