Texture formation is frequently observed in parts produced by Laser Powder Bed Fusion (L-PBF), which can induce anisotropy and may potentially degrade plasticity. In this study, we introduce a laser remelting strategy to mitigate these adverse effects. By employing experimental observations and numerical simulations, we established the relationship between melt pool thermal history, variant selection, and mechanical properties. Our results indicate that the strengthening of texture can be prevented by disrupting the variant selection memory effect when there is a difference in scanning speeds between the printing and remelting lasers. The achieved random variant orientation is attributed to the altered cooling rates and temperature gradient directions during solidification across different layers. The optimized Ti-6Al-4V alloy demonstrates high strength (1211.5 ± 13.3 MPa) and significant elongation (12.3 % ± 0.8 %), exhibiting a superior strength-ductility synergy compared to samples produced by direct printing or laser remelting with consistent parameters, as well as most reported L-PBF processed Ti-6Al-4V alloys. Our findings provide new insights into phase transformation kinetics in L-PBF of Ti-6Al-4V alloys and facilitate the optimization of this process for manufacturing high-performance components.

中文翻译：

---

破坏激光粉末床熔融中的变体选择记忆效应，以提高 Ti-6Al-4V 合金的强度-延展性协同效应


在激光粉末床熔融 （L-PBF） 生产的部件中经常观察到纹理形成，这会引起各向异性，并可能降低塑性。在这项研究中，我们引入了一种激光重熔策略来减轻这些不利影响。通过采用实验观察和数值模拟，我们建立了熔池热历史、变体选择和机械性能之间的关系。我们的结果表明，当打印和重熔激光器之间的扫描速度存在差异时，可以通过破坏变体选择记忆效应来防止纹理增强。实现的随机变体取向归因于不同层凝固过程中冷却速率和温度梯度方向的改变。优化的 Ti-6Al-4V 合金表现出高强度 （1211.5 ± 13.3 MPa） 和显着的伸长率 （12.3 % ± 0.8 %），与通过直接打印或激光重熔生产的样品相比，表现出卓越的强度-延展性协同作用具有一致的参数，以及大多数报道的 L-PBF 加工的 Ti-6Al-4V 合金。我们的研究结果为 Ti-6Al-4V 合金的 L-PBF 相变动力学提供了新的见解，并有助于优化这一工艺以制造高性能部件。