Characterization and development of metal powder suspensions for incorporation into fiber composites with regard to stability, fiber adhesion and influence on mechanical properties

Fiber-reinforced plastics (FRPs) are increasingly being used in modern aircraft construction due to their low weight combined with good mechanical properties. Due to the progressive replacement of conventional materials in aviation, their characteristic values also have to be optimized.

One well-known method is the introduction of fillers into the material. In this way, the mechanical, optical, electrical and thermal properties can be significantly influenced. For example, the addition of graphite to GFRP serves to improve conductivity and the addition of aluminum hydroxide to optimize fire behavior.

In the present work, stable suspensions based on various fillers are to be developed for incorporation into fiber-reinforced composites. The focus is on the stability of the suspension (sedimentation, dispersion), the bonding of the fillers in the fiber composite and the resulting mechanical properties.

The aim of the work is to analyze the influences of different additives on defined target properties of metal powder suspensions. At the beginning, suitable additives are to be defined, characterized and selected with regard to their function in a literature research. In a systematic experimental program, suspensions with different mixing ratios are to be prepared and analyzed for defined target parameters. With the aid of suitable test methods, the rheological characteristics of the suspensions and the effect on the fiber-filler matrix bond are to be determined. Subsequently, the relationships and interactions of each component to each other and to the target variables are to be worked out and presented.

The following items will be addressed as part of the work:

  • Literature research on the subject of metal powder suspensions, suitable rheology additives and their influence.
  • Creation of an experimental plan with the help of the statistical design of experiments (DOE)
  • Independent execution of experiments after appropriate equipment instruction and investigation of the defined target variables
  • Data evaluation of the statistical design of experiments and establishment of correlations