Application of a new method for accurate determination of a and ß texture in Ti-6Al-4V from synchrotron diffraction intensities
Application of a new method for accurate determination of a and ß texture in Ti-6Al-4V from synchrotron diffraction intensities
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应用同步加速器衍射强度准确测定 Ti-6Al-4V 中 a 和 α 织构的新方法
DOI：
10.1016/j.matchar.2023.112769
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发表时间：
2023
影响因子：
4.7
通讯作者：
Daniel C
中科院分区：
文献类型：
--
作者：
Daniel C
双相钛合金如Ti-6Al-4 V在加工过程中的晶体学织构发展具有重要的技术意义。然而，由于织构的空间不均匀性和在室温下少数β相的低体积分数，测量这些材料中两个相中的织构是一个重大挑战。在这里，我们演示了如何同步辐射X射线衍射可以用来克服这些困难，并测量在热轧样品的织构和织构变化的可重复的方式。从沿着不同方向获得的二维同步辐射衍射图计算了热轧Ti-64中的织构。使用基于衍射强度的Rietveld细化的MAUD和使用直接从2D衍射图案提取强度的基于傅立叶级数的分析方法分析数据，然后使用开源软件MTEX拟合取向分布函数（ODF）。通过与真实的EBSD测量结果的比较，我们表明傅里叶级数方法产生更准确的织构测量，特别是对少数β相。我们还表明，至少2个，最好是3个，需要不同的测量方向，以充分代表纹理。这意味着依赖于来自单个样品取向的衍射数据的纹理测量，如快速原位研究或空间分辨测量，只能提供定性信息，必须小心解释。
The crystallographic texture development during processing of dual-phase Ti alloys like Ti-6Al-4 V is of fundamental technological importance. However, measuring texture in both phases in these materials is a significant challenge because of the spatial inhomogeneity of the texture and low volume fraction of the minority β-phase at room temperature. Here we demonstrate how synchrotron X-ray diffraction can be used to overcome these difficulties and measure texture and texture variation in hot-rolled samples in a reproducible manner. The texture in hot-rolled Ti-64 was calculated from 2D synchrotron diffraction patterns obtained along different directions. The data was analysed using MAUD, which is based on Rietveld refinement of the diffracted intensities, and using a Fourier series based analysis method, that extracts intensities directly from the 2D diffraction patterns, and then uses the open-source software MTEX to fit an orientation distribution function (ODF). By comparing the results with faithful EBSD measurements, we show that the Fourier series method produces much more accurate texture measurements, especially for the minority β-phase. We also show that a minimum of 2, and preferably 3, different measurement orientations are needed to fully represent the texture. This implies that measurements of texture which rely on diffraction data from a single sample orientation, like in fast in-situ studies or spatially resolved measurements, can only provide qualitative information and must be interpreted with care.