The dissimilar resistance spot welding of additively manufactured steel to conventional automotive steel has attracted significant attention from automotive manufacturer. However, the mechanical properties of dissimilar spot welds could be affected by the printed properties of additively manufactured steels, limiting the further application of 3D printing process in auto-body assembly line. This paper proposed an approach to improve the mechanical properties of spot-welded joints of additive manufactured steels by the design of binder jetting printed steels with the addition of nanoparticles. Cu-Sn nanoparticles have been injected to the stainless steel via binder jetting process, aiming to fill the voids between steel particles and reduce the microstructure heterogeneity in the spot welds. The microstructure evolution, sintering behavior of nanoparticles and mechanical properties of resistance spot welded stainless steel were characterized and analyzed. The sintering behavior of Cu-Sn nanoparticles during welding process attributes to the formation of transition zone with homogenous microstructure, resulting to the improvement of hardness property and lap-shear strength of spot-welded joints. Compared to the spot welds of selective laser melting printed stainless steels, the resistance spot welded stainless steel via binder jetting process shows better mechanical properties with 48 % increase of energy absorption and 19 % increase of peak load.

增材制造钢与常规汽车钢的不同电阻点焊引起了汽车制造商的极大关注。但是，异种点焊的机械性能可能会受到增材制造钢的印刷性能的影响，从而限制了3D打印工艺在车身装配线中的进一步应用。本文提出了一种通过添加纳米颗粒的粘结剂喷射印刷钢的设计来改善增材制造钢点焊接头机械性能的方法。Cu-Sn纳米粒子已通过粘结剂喷射工艺注入到不锈钢中，目的是填充钢粒子之间的空隙并减少点焊的微观结构异质性。微观结构的演变，对纳米粒子的烧结行为和电阻点焊不锈钢的力学性能进行了表征和分析。Cu-Sn纳米粒子在焊接过程中的烧结行为归因于具有均匀组织的过渡区的形成，从而改善了点焊接头的硬度和搭接剪切强度。与选择性激光熔化印刷不锈钢的点焊相比，通过粘结剂喷射工艺进行的电阻点焊不锈钢具有更好的机械性能，能量吸收增加了48％，峰值载荷增加了19％。Cu-Sn纳米粒子在焊接过程中的烧结行为归因于具有均匀组织的过渡区的形成，从而改善了点焊接头的硬度和搭接剪切强度。与选择性激光熔化印刷不锈钢的点焊相比，通过粘结剂喷射工艺进行的电阻点焊不锈钢具有更好的机械性能，能量吸收增加了48％，峰值载荷增加了19％。Cu-Sn纳米粒子在焊接过程中的烧结行为归因于具有均匀组织的过渡区的形成，从而改善了点焊接头的硬度和搭接剪切强度。与选择性激光熔化印刷不锈钢的点焊相比，通过粘结剂喷射工艺进行的电阻点焊不锈钢具有更好的机械性能，能量吸收增加了48％，峰值载荷增加了19％。