The importance of application-specific materials is steadily increasing and is being challenged even more by metallic 3D printing. Due to the high geometrical freedom of design and the almost complete material yield, material costs play only a minor role in some printed application examples. When it is important to decrease the thermal expansion or increase the thermal conductivity, monolithic materials reach their limits. Therefore, composites are in the focus, which combines the positive properties of two fundamental different materials in one. The aluminium matrix composites unite the advantages of aluminium (high thermal conductivity, low density, corrosion resistance) and ceramic particles (hardness, low thermal expansion, high specific heat capacity). Using a novel casting process, the SiC particles are injected under the surface of the standard aluminium alloy (AlSi9Mg) and impellers distribute and wet the SiC particles homogeneous in aluminium matrix. A controlled solidification process allows that the initial particle concentration can be increased from 30 vol.-% up to 50 vol.-%. The cast rods were atomized by using a plasma arc as well as an induction melting process with high frequented ultrasonic to produce d50 particles between 40 and 60 µm. These AMC particles are characterized by an all-round coating of the SiC particles, which enables excellent print quality to be achieved in selective laser melting. By varying the particle size and volume fraction, the material properties can also be further optimised according to the application. For example, the thermal expansion correlate with particle concentration – the thermal expansion coefficient decrease with increased volume fraction of reinforced particles.