Study on the detailed micro-structural characteristics of Laser Cladding in terms of porosity distribution, dilution of alloying elements and stresses in the laser melted zone using focused ion beam tomography

使用聚焦离子束断层扫描研究激光熔覆的详细微观结构特征，包括激光熔化区的孔隙率分布、合金元素的稀释度和应力

• 批准号: 165626081
• 负责人: Professor Dr.-Ing. Frank Mücklich
• 金额: --
• 依托单位: Department of Metallurgical Engineering & Material Science
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/165626081?language=en
• 关键词: Study; detailed; micro; structural; characteristics

Surface modifications by laser are being practiced now for the last 1-2 decades. There have been several publications, where different surface property modifications have been studied. This includes mainly, corrosion, oxidation, wear, friction and hardness. Useful information obtained from these siudies has also helped in adaption of this technique by various industries, as an alternative process. For example, laser hardening has been adopted by many industries in place of conventional case-carburizing, ion-nitriding and plasma nitriding. Laser alloying and cladding have been extended to the repair of several complicated and expensive components such as ship parts, crank shafts and aero-engine turbine blades. We have been carrying oul work on laser surface alloying and cladding and contributed towards the modification of surfaces, such as steel, stainless steels, titanium in terms of their corrosion, oxidation and wear behavior. Detailed studies confirm the surface modification as per the mechanism of oxidation and corrosion. We have also used this technique to fabricate near-net shaped components using laser forming.It is however, felt that the micro-mechanisms within the laser melted zone or cladding are still not clear. Whether it is the role of densification due to laser treatment or it is the change in microstructure (amorphous or micro-crystalline) and also the role of dilution of the alloying elements is not very clear. During our recent interactions and my short stay at the chair of functional materials (Prof. Dr. F. Mücklich) at Saarland University, I found a dedicated interest towards this kind of study. The instituie has basic laser facilities and is very strong in micro-structural evaluations using sophisticated techniques such as focused ion beam tomography and XRD and other surface analytical tools. It was therefore proposed to work together on this field - with our strong expertise in laser alloying and cladding and their strong expertise in micro-structural evaluations.

激光表面改性在过去的1- 20年里一直在实践。已经有几个出版物，其中已经研究了不同的表面性质改性。这主要包括腐蚀、氧化、磨损、摩擦和硬度。从这些研究中获得的有用信息也有助于各行业采用这种技术作为替代工艺。例如，激光淬火已被许多工业采用，以取代传统的表面渗碳，离子渗氮和等离子渗氮。激光合金化和熔覆技术已应用于船舶零件、曲轴、航空发动机涡轮机叶片等复杂昂贵零件的修复。我们一直在进行激光表面合金化和熔覆方面的工作，并为钢、不锈钢、钛等表面的腐蚀、氧化和磨损行为的改性做出了贡献。详细的研究证实了表面改性的氧化和腐蚀的机制。我们也利用这项技术来制造近终形零件，然而，感觉到激光熔化区或熔覆层内的微观机制仍然不清楚。无论是由于激光处理的致密化作用，还是微观结构（非晶或微晶）的变化，以及合金元素的稀释作用，都不是很清楚。在我们最近的互动和我在功能材料主席（F教授博士）的短暂停留。Mücklich）在萨尔兰大学，我发现了对这类研究的浓厚兴趣。该研究所拥有基本的激光设备，并在使用诸如聚焦离子束层析成像和XRD以及其他表面分析工具等复杂技术进行微观结构评估方面非常强大。因此，我们建议在这一领域开展合作-我们在激光合金化和熔覆方面拥有强大的专业知识，而他们在微观结构评估方面拥有强大的专业知识。