Development of new AlSi-alloys reinforced with titanium-based particles for laser powder bed fusion: tension and rotary bending fatigue tests

The use of additive manufacturing in industry and research rises consistently. As new applications for this manufacturing method emerge, their implementation requires material optimization for additive manufacturing. Through the use of TiC and TiB₂ particle admixtures to different AlSi-alloys, possible improvements in density and moreover, static mechanical and high cycle fatigue properties were investigated. This allows a wider variety of components to be manufactured, as these AlSi-alloys with particle admixtures can endure higher loads in comparison to previously used AlSi-alloys. The different material compositions which were manufactured from mixed powders have undergone tensile and rotary bending fatigue tests. The porosity, the hardness and the particle distribution as indicators of the quality and applicability of the materials were determined and compared to pure AlSi-alloys. Within the scope of this study, an AlSi16 alloy with a particle admixture of µm-sized TiB₂ with a mass percentage of 12% achieved the best results, namely a yield and tensile strength of 299 MPa and 445 MPa, respectively, in addition to a Young´s modulus of 88.6 GPa. In comparison to other conventionally used materials, AlSi16 with micro TiB₂ admixtures showed noteworthy improvements.