For the first time, the novel combination of multi-pass equal channel angular extrusion/pressing (ECAE/P) and selective laser melting (SLM) was investigated. Herein, four passes of ECAP via route B_c at 150 °C were applied as a severe plastic deformation (SPD) technique on the SLM as-built AlSi12 to promote superior mechanical properties. The microstructure and mechanical behavior of AlSi12 fabricated by SLM were studied before and after ECAP, applying several mechanical and microstructural characterization techniques. Results of the tensile experiments revealed that the yield point, the ultimate strength, and the ductility of the as-built sample were improved by 56%, 11%, and 55% after 4 passes of ECAP, respectively. This enhancement is attributed to the effective grain refinement and the persisting silicon phase network after SPD as evidenced by electron backscatter diffraction and elemental mapping results. Moreover, micro-computed tomography analysis disclosed that ECAP considerably reduces the remnant porosity of the post-treated SLM AlSi12 samples eventually further affecting the strength of the ultra-fine grained AlSi12 in a positive way. Findings presented herein indicate that it is viable to utilize ECAP as a post-AM processing tool for mechanical property improvement of laser powder bed fused microstructures with the virtue of enhanced densification. Even if geometrical restrictions exist in ECAP, results obtained herein are transferrable to other SPD techniques with suitable processing windows, which would pave the way to advanced properties of adequately post-treated conditions.

首次研究了多道次等通道角挤压/压制 (ECAE/P) 和选择性激光熔化 (SLM) 的新型组合。在此，通过路线 B _{c 的}四次 ECAP在 150 °C 的温度下作为严重塑性变形 (SPD) 技术应用于 SLM 竣工 AlSi12 以提高优异的机械性能。在 ECAP 之前和之后，研究了 SLM 制造的 AlSi12 的微观结构和力学行为，应用了几种力学和微观结构表征技术。拉伸试验结果表明，经过 4 次 ECAP 后，竣工样品的屈服点、极限强度和延展性分别提高了 56%、11% 和 55%。这种增强归因于有效的晶粒细化和 SPD 后持续存在的硅相网络，如电子背散射衍射和元素映射结果所证明的那样。而且，显微计算机断层扫描分析表明，ECAP 显着降低了后处理 SLM AlSi12 样品的残余孔隙率，最终进一步以积极的方式进一步影响超细晶粒 AlSi12 的强度。本文中的研究结果表明，利用 ECAP 作为 AM 后加工工具，通过增强致密化来改善激光粉末床熔融微结构的机械性能是可行的。即使在 ECAP 中存在几何限制，本文获得的结果也可以转移到具有合适处理窗口的其他 SPD 技术，这将为充分后处理条件的高级特性铺平道路。本文中的研究结果表明，利用 ECAP 作为 AM 后加工工具，通过增强致密化来改善激光粉末床熔融微结构的机械性能是可行的。即使在 ECAP 中存在几何限制，本文获得的结果也可以转移到具有合适处理窗口的其他 SPD 技术，这将为充分后处理条件的高级特性铺平道路。本文中的研究结果表明，利用 ECAP 作为 AM 后加工工具，通过增强致密化来改善激光粉末床熔融微结构的机械性能是可行的。即使在 ECAP 中存在几何限制，本文获得的结果也可以转移到具有合适处理窗口的其他 SPD 技术，这将为充分后处理条件的高级特性铺平道路。