铝基钛坯高温防氧化涂层界面结构研究

Interface structure of titanium billet surface and high temperature oxidation resistant aluminum-base coatings

摘要:

以Al粉为主料,Sn粉、SiO2粉、苯丙乳液、聚乙烯醇、羧甲基纤维素等为配料制备高温防氧化涂料。将涂料喷涂到钛坯表面,然后置于1050 ℃条件恒温8 h,对比喷涂与热处理前后钛坯表面形貌。利用金相显微镜观察裸露面和喷涂面经热处理后的氧化层组织,使用场发射扫描电镜、能谱分析仪研究涂层界面处的微观形貌和元素扩散,采用X-射线衍射仪探讨涂层界面处的相结构。结果表明,使用铝基高温防氧化涂层能够有效的减缓钛坯热加工过程中高温氧化,涂层厚度对Ti-Al扩散层的厚薄无明显影响,扩散层形成了Al2O3-TiAl和TiAl3-Ti多层结构,且涂层厚度为50 μm左右时已经具有较好效果。

Abstract:

Titanium billet surface high temperature oxidation resistant coatings were prepared with Al powder as mainly raw material and Sn powder, SiO2 powder, styrene acrylic emulsion, polyvinyl alcohol, sodium carboxymethyl cellulose as burdening. Subsequently, the coating is sprayed onto the surface of titanium billet, and placed in constant temperature conditions of 1050 ℃ for 8 h, and then in comparison with the surface topography of the flakes with coating or not. The microstructure of the exposed surface and spraying surface analyzed by optical microscope, the coating microstructure and elements diffusion analyzed by field emission scanning electron microscopy and energy spectrum analysis instrument, the interface phase structure analyzed by X- ray diffraction. The results show that titanium billet surface with high temperature oxidation resistant coatings can effectively reduce the thermal processing of titanium billet spalling, the effect of the coating thickness on the thickness of Ti-Al diffusion layer is not significant, the Al2O3-TiAl layers and TiAl3-Ti multilayers co-formed the coating layer, moreover, the excellent coating thickness is about 50 μm .