High melting nanoparticles like titanium carbide TiC are often added to aluminium alloy powders for additive manufacturing e.g. laser powder bed fusion PBF-LB/M. Especially in high-strength and hot crack sensitive Al-Cu-Mg and Al-Zn-Mg alloys, those nanoparticles shall act as nuclei during rapid solidification and thereby form a fine-grained equiaxed microstructure and suppress hot cracking. This successful approach has been correlated with low melt undercooling during rapid solidification. Due to their high thermal stability, these nanoparticles remain unchanged in the additively manufactured components during further processing and application. In these stages, the nanoparticle influence has not been investigated yet. Heat treatment like age hardening of high strength aluminium alloys is a typical post-processing step of PBF-LB/M components. Usually the high cooling rates during PBF-LB/M form a supersaturated solid solution, which can be aged directly. High melting nanoparticles in the microstructure can influence on heat treatability in several ways. First, nanoparticles can act as nuclei for coarse precipitation of intermetallic phases during further cooling of PBF-LB/M components after solidification. This would reduce ageing potential. Second, nanoparticles may also act as nuclei for precipitation of fine strengthening particles during subsequent ageing. This would accelerate ageing kinetics. We have investigated PBF-LB/M samples of alloy AlSi10Mg without and with nanoparticles TiC, respectively SiC and different building parameters. Afterwards, the ageing behaviour has been investigated by continuous heating in a differential scanning calorimeter, isothermal ageing and hardness testing as well as electron microscopy.