The increasing demands placed on components in the industrial environment, such as tool and mould making, require the use of high-strength steels. Maraging steels have very good machinability in the solution-annealed condition and achieve maximum strength combined with high toughness through suitable heat treatment. The combination with a good weldability makes these steels suitable for additive manufacturing and the maraging steel 1.2709 is widely used in laser powder-bed fabrication (LPBF). Laser metal deposition (LMD) is another laser-based process with increasing importance for tools and moulds. This process can be used for manufacturing of large-volume components and moulds repair.

The aim of the present study is the investigation of the mechanical properties of LMD-built samples made of the powder material PLASWeld Ferro702 (Ferro702) and the comparison to the properties of commercially available material 1.2709. The chemical compositions of both materials are very similar. The mechanical properties are characterised by means of tensile and hardness tests in combination with the microstructure analysis. The shape of the micro tensile specimens used in this study is more suitable for additive processes as it requires much smaller build-up volume. The influence of the specimen size on the measured values is initially evaluated by comparing the testing results obtained for the conventionally produced material 1.2709 with the standard specimen shape C6 and the corresponding micro tensile specimens. The final mechanical characterisation for different heat treatments is then carried out using micro tensile tests of 1.2709 and the additively manufactured Ferro702.

For the "as built" and heat-treated conditions (6 hours at 490 °C) the influence of the build-up orientation (0° and 90°) is also analysed. For the conventional material the heat treatment conditions (solution annealing at 850 °C with quenching; 6 hours at 490 °C) have been applied. The results show that the respective tendencies of the measured mechanical properties after heat treatment of 1.2709 and Ferro702 are similar. However, the achievable mechanical properties of the Ferro702 with the same heat treatment conditions are lower, so that further optimisation of the post treatment parameters for the LMD processed material is required.