Friction stir welding (FSW) was introduced to join laser powder bed fusion (LPBF) AlSi10Mg alloys in this study. Microstructure and texture evolution, microhardness distribution and tensile properties of the FSW joints were investigated. The evolution of grain size, grain boundary and misorientation angles distribution, dynamic recrystallization and crystallographic texture in various regions of the FSW joint concerning base metal (BM), thermo-mechanically affected zone (TMAZ), upper part of nugget zone (UPNZ) and low part of nugget zone (LPNZ) was characterized by using electron back-scattered diffraction (EBSD). The analysis reveals a strong texture evolution of shear components on the TMAZ, UPNZ and LPNZ as well as a fully recrystallized grain structure on the UPNZ and LPNZ. Additionally, a gradual evolution in Si-rich eutectic from continuous cellular networks in the BM to totally globularized particles in the UPNZ and LPNZ occurs in the FSW joint. The microhardness rapidly decreases to the TMAZ from the BM through heat affected zone (HAZ) reaching the lowest value of ∼65.0 HV at the TMAZ/NZ boundary. The FSW joint in LPBF AlSi10Mg alloys exhibits an ultimate tensile strength (UTS) of 247 MPa and an elongation-to-failure (EI) of 8.8%. The UTS of FSW joints is reduced compared to the BM, but the EI has been increased by 160%, implying an improvement in tensile ductility.

本研究引入搅拌摩擦焊 (FSW) 来连接激光粉末床熔合(LPBF) AlSi10Mg 合金。研究了 FSW 接头的微观结构和织构演变、显微硬度分布和拉伸性能。FSW接头各区域的晶粒尺寸、晶界和取向差角分布、动态再结晶和晶体织构的演变，涉及母材（BM）、热机械影响区（TMAZ）、熔核区上部（UPNZ）和使用电子背散射衍射（EBSD）对熔核区低部分（LPNZ）进行了表征。分析揭示了 TMAZ、UPNZ 和 LPNZ 上剪切分量的强烈织构演化以及UPNZ 和 LPNZ 上完全再结晶的晶粒结构。此外，在 FSW 接头中，富硅共晶从BM 中的连续蜂窝网络逐渐演变为 UPNZ 和 LPNZ 中的完全球化颗粒。显微硬度从 BM 通过热影响区 (HAZ) 到 TMAZ 迅速降低，在 TMAZ/NZ 边界处达到最低值 ∼65.0 HV。LPBF AlSi10Mg 合金的 FSW 接头的极限拉伸强度 (UTS) 为 247 MPa，断裂伸长率 (EI) 为 8.8%。FSW 接头的 UTS 与 BM 相比有所降低，但 EI 却增加了 160%，这意味着拉伸延展性有所改善。