The unique thermokinetics of laser-powder bed fusion additive manufacturing (L-PBFAM) has been exploited for development of a novel high-strength Al-Ni-Ti-Zr-Mn alloy. The addition of 0.5 wt% Mn leads to extraordinary improvement in ultimate tensile strength (502 MPa) and work hardening due to the activation of two Mn-induced strengthening mechanisms. First, by a bimodal particle strengthening effect due to Al₃₁Mn₆Ni₁₂ nano-quasi-crystal particles rejected in inter-dendritic spaces and fibrous Al₃Ni eutectic dendritic channels, which predominately contributes to the strength improvement, and second by solid solution strengthening from remaining Mn entrapped in Al. These mechanisms supplement the particle strengthening effect imparted by coherent and incoherent Al₃(Ti,Zr) co-precipitates present at melt pool boundaries, dislocation strengthening due to solidification induced strain, and Hall-Petch and backstress strengthening effect due to heterogenous grain size distribution occurring at various length scales. The solidification dynamics and hierarchical heat distribution that are associated with L-PBFAM resulted in complex spatial variations in these strengthening phenomena and were investigated via a high-throughput multiscale structure–property correlation that involved thermokinetic simulation, X-ray diffraction, high-resolution nanoindentation mapping, and site-specific transmission electron microscopy of the alloy.

激光粉末床熔融增材制造 (L-PBFAM) 的独特热动力学已被用于开发新型高强度 Al-Ni-Ti-Zr-Mn 合金。由于激活了两种锰诱导强化机制，添加 0.5 wt% Mn 可显着提高极限抗拉强度 (502 MPa) 和加工硬化。首先，由于 Al ₃₁ Mn ₆ Ni ₁₂纳米准晶颗粒被排除在枝晶间空间和纤维状 Al ₃ Ni 共晶枝晶通道中，从而产生双峰颗粒强化效应，这主要有助于强度的提高，其次是通过固溶体通过铝中剩余的锰来强化。这些机制补充了熔池边界处存在的共格和非共格 Al ₃ (Ti,Zr) 共沉淀物所赋予的颗粒强化效应、由于凝固引起的应变而产生的位错强化以及由于不均匀晶粒尺寸分布而产生的 Hall-Petch 和背应力强化效应发生在不同的长度尺度。与 L-PBFAM 相关的凝固动力学和分层热分布导致了这些强化现象的复杂空间变化，并通过涉及热动力学模拟、X 射线衍射、高分辨率纳米压痕的高通量多尺度结构-性能相关性进行了研究合金的绘图和位点特定透射电子显微镜。