Powder modification became a popular solution to adopt crack-free high-strength aluminium alloys for powder bed fusion additive manufacturing. A tool to guide these modifications is proposed. Laser beam fusion implies heating and cooling at rates up to 10⁶ K/s. In-situ characterization of powder melting and solidification at these rates is only possible using Fast Scanning Calorimetry. It was found that modification of powder strongly influences it’s solidification kinetics. In particularly the solidification temperature at 10,000 K/s is significantly higher for TiC nanoparticles-modified aluminium alloy AA7075, in comparison to non-modified powder. The results are strongly correlating with the microstructure of additive manufactured parts. This makes the FSC a powerful tool for powder characterization and guiding powder modification. New approach for data analysis and sample preparation is discussed for screening of large number of particles for industrial application.