Additive manufacturing, e.g. by laser powder bed fusion (LPBF), is very attractive for lightweight constructions,
as complex and stress-optimised structures integrating multiple functions can be produced
within one process. Unfortunately, high strength AlZnMgCu alloys tend to hot cracking during LPBF
and thus have not so far been applicable. In this work the melting and solidification behaviour of
AlZnMgCu alloy powder variants with particle surface inoculation was analysed by Differential Fast
Scanning Calorimetry. The aim is to establish a method that makes it possible to assess powder modifications
in terms of their suitability for LPBF on a laboratory scale requiring only small amounts of powder.
Therefore, solidification undercooling is evaluated at cooling rates relevant for LPBF. A method for the
temperature correction and normalisation of the DFSC results is proposed. Two ways of powder modification
were tested for the powder particles surface inoculation by titanium carbide (TiC) nanoparticles:
via wet-chemical deposition and via mechanical mixing.
A low undercooling from DFSC correlates with a low number of cracks of LPBF-manufactured cubes. It
appears that a reduced undercooling combined with reduced solidification onset scatter indicates the
possibility of crack-free LPBF of alloys that otherwise tend to hot cracking.