铝基非晶纳米晶复合涂层多相耦合微区腐蚀规律研究

Based on the materials preparation and formation integration idea, a type of Al-based amorphous and nanocrystalline composite coating with excellent corrosion resistance was prepared by automatic arc spraying cored wire process, which was used to protect marine aluminum alloy equipments from corrosion. It is a new production technology of the Al-based amorphous alloy. And it can provide a reliable protective material for the surface protection and maintenance and remanufacturing of marine equipments. Through monitoring the velocity and temperature of the flying particles and the temperature field distribution on the surface of the coating, and analysising the microstructure of the coating, the formation mechanism of the amorphous and nanocrystalline phases in the coating was revealed. There are amorphous, nanocrystalline phase, crystalline phase, and oxide in the coating. The microzone corrosion laws of the coupled multiphase and the influence function of them to the corrosion resistance of the whole coating were researched. The mapping relationship of alloy design and preparation process and microstructure and corrosion mechanism and corrosion resistance can be bulit for the preparation of the composite coating. The new type of Al-based amorphous and nanocrystalline composite coating has expected performances as shown below, the bond strength between the coating and aluminum alloy with more than 35 MPa, the amorphous volume fraction with more than 25%, the porosity with less than 1%, the hardness with more than HV350, the corrosion resistance of the coating improved more than 2 times as compared to the conventional Al coatings.

针对海洋装备铝合金腐蚀防护问题，基于材料制备与成形一体化思路，拟采用自动化高速电弧喷涂技术制备具有长效防腐功能的铝基非晶纳米晶复合涂层，拓展铝基非晶态材料制备技术，为海洋装备表面防护、维修与再制造提供可靠的防护涂层材料支撑。监测涂层形成过程中飞行粒子速度和温度变化及涂层表面温度场分布，分析涂层微观组织结构，揭示涂层非晶、纳米晶相形成机理，研究涂层非晶、纳米晶相、晶化相及氧化物相等多相耦合微区腐蚀规律，以及各物相对涂层综合防腐性能的影响作用；建立“合金成分设计-涂层制备工艺-微观组织结构-各物相腐蚀失效机制-涂层综合防腐性能”之间的映射关系。新型Al基非晶纳米晶复合涂层的预期性能指标为：结合强度大于35MPa，非晶含量大于25%，孔隙率小于1%，硬度大于HV350，综合防腐性能较传统Al涂层提高2倍以上。

本项目通过粉芯丝材制备技术自主研发了铝基粉芯丝材，采用高速电弧喷涂技术在45钢和6061铝合金表面制备了铝基非晶纳米晶复合涂层，研究了涂层的微观组织结构、力学性能和防腐蚀性能，揭示了涂层中非晶、纳米晶及氧化相腐蚀失效规律，为海洋表面防护提供了理论支撑。本项目的成果有：获得了2种用于制备铝基非晶纳米晶涂层的粉芯丝材；制备的Al-Fe-Nb-Si和Al-Ni-Nb-Fe涂层均由非晶、纳米晶和氧化相组成，非晶含量分别为68vol.%和72vol.%，涂层孔隙率分别为0.8%和0.7%，显微硬度值分别为HV0.1387和HV0.1370，与6061铝合金基体的平均结合强度值分别为38.8MPa和36.2MPa，涂层防腐蚀性能为纯Al涂层的3倍以上，各项性能指标均满足预期技术指标。项目研究过程中取得成果有：①发表基础研究论文8篇（包括期刊论文7篇、会议论文1篇），其中被SCI收录3篇、被EI收录3篇；②发明专利授权2项、受理2项；③培养博士后1名、硕士研究生1名。