Evaluating the effect of heat input on residual stress, texture and corrosion resistance in friction-stir-welded L-PBF AlSi10Mg alloy

Metal 3-D printing, such as laser powder bed fusion, is capable of printing intricate parts with limitless design freedom. Despite design freedom, the maximum size that can be printed is a hindrance to the emerging technology. Therefore, joining and evaluating welded joints are critical for making them more viable for a wider range of applications. Thus, the present study examines the impact of tool rotational speeds on friction-stir-welded joints, revealing that an increase from 600 to 1200 revolutions per minute (RPM) raises the stir zone's temperature from 270.0 to 329.9 °C and residual stresses from 46.7 to 93.1 MPa. An optimum tensile strength of 260 MPa was observed at 800 RPM with a grain size of 2.6 µm, whereas the lowest strength of 172 MPa occurred at 1200 RPM with a 4.21 µm grain size. Additionally, the corrosion resistance decreased with increasing residual stress, showing the highest resistance at 600 RPM ( E corr = − 1.0737 V) and the lowest at 800 RPM ( E corr = − 1.2027 V). The study also found a decrease in grain density with higher rotational speeds and localized corrosion due to microgalvanic coupling between Si particles and the α-Al matrix. Moreover, the shear components C {001} were identified as being particularly susceptible to corrosion attacks. This specific component significantly contributes to the reduced corrosion resistance observed in the joints.