Effect of wetting on the incorporation behavior of powder particles in laser melt injection at high processing speed

• Applicant: Dr.-Ing. Thomas Seefeld
• Subject Area: Joining and Separation Technology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 495532447

Although laser melt injection offers clear technological advantages over other processes for producing functional component surfaces, this process has not yet been widely accepted in industry due to low process speeds and the associated low productivity. Current investigations however indicate that high speed melt injection can be feasible. Moreover, at this point the process is limited to the use of metallic hard materials with good wettability, while oxide particles cannot be processed due to poor wettability. Therefore, the overall goal of the project is to better understand the process of laser melt injection at high process speeds. This understanding should enable an extension of the current process limits in terms of maximal process speed, achievable hard particle content at high process speed, and also in terms of feasibility of using oxide particles.In particular, the project aims to generate an understanding of the incorporation behavior of powder particles in the melt pool during laser melt injection. Differences between a process at low speed and a process at high speed are to be identified. The incorporation behavior of powder particles is to be correlated with the input factors wettability of the hard materials by the substrate melt, density ratio of particles and substrate melt and kinetic energy of the powder particles. Through identification of the main influencing parameters, a high speed laser melt injection process shall be developed that still allows for the incorporation of a high hard particle content. To improve the wettability of the hard materials, titanium coated hard particles shall be investigated for the first time in laser melt injection. In particular, this should enable the use of oxidic hard materials in laser melt injection. In addition, the improved wettability should ensure that sufficient particles incorporate into the melt pool even at very high process speeds in order to achieve a high hard particle content in the MMC coatings.

• DFG Programme: Research Grants