Abstract Laser based additive manufacturing allows to build a designed shape layer-by-layer, offering versatility and flexibility to many metallurgical sectors. The fast cooling rates and repeated heat cycles depending on the laser and scanning parameters are not easily measurable with conventional methods. Thus, advanced predictive computational simulations, required to reduce trial and error lead time, are difficult to validate. A newly developed in operando X-ray diffraction device implemented at a synchrotron beamline, taking advantage of the high brilliance and the fast detectors available, brings the missing link with numerical methods. By performing operando experiments on Ti-6Al-4V with different printing parameters, the temporal evolution of the low and high temperature phases are followed, the heating and cooling rates are measured for the powder and the solid material; and the formation of residual stresses in the β phase is demonstrated. Moreover it is shown that the parameter that has the largest influence on the evolving microstructure is the scanning strategy, introducing a size effect related to the scanning length.

中文翻译：

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激光 3D 打印过程中的操作数 X 射线衍射

摘要 基于激光的增材制造允许逐层构建设计形状，为许多冶金行业提供多功能性和灵活性。使用传统方法不容易测量取决于激光和扫描参数的快速冷却速率和重复热循环。因此，减少试错交付时间所需的高级预测计算模拟很难验证。一种新开发的在同步加速器光束线上实现的操作 X 射线衍射设备，利用高亮度和可用的快速探测器，带来了与数值方法的缺失环节。通过对具有不同印刷参数的 Ti-6Al-4V 进行操作实验，跟踪低温和高温相的时间演变，测量粉末和固体材料的加热和冷却速率；并证明了 β 相中残余应力的形成。此外，研究表明，对微观结构演变影响最大的参数是扫描策略，它引入了与扫描长度相关的尺寸效应。