Failure mechanism data related to the crack path of additively manufactured Ti-6Al-4V reiforced by nano-sized particules

Various kinds of data (i.e., Photographs, Matlab Executable Script, Excel files, EBSD data set) has been gathered in the present repository to give a comprehensive overview of the fracture surface morphology observed on the fracture surface of a novel metallic matrix composite (MMC) based Ti-6Al-4V alloy processed by laser-powder bed fusion (L-PBF) technique. Alike its unreinforced counterparts, such additively manufactured (AMed) Ti-6Al-4V tends to present clear inclined planes on the fracture surface macroscopically (the so-called "stair-like" pattern). In other words, the crack path does not obey to the mode I fracture plane in this zone. Furthermore, based on eight (8) different specimens, the fraction of stair-like pattern occurrence on the fracture surface varies from 4.6 to 17.6%. Outside this stair-like pattern, the fracture surface presents mode I fracture plane and shear lip next to lateral surface of the specimen.
To clarify the reason for this peculiar behavior, one specimen presenting such a fracture surface pattern has been sliced at a position where the fracture surface presents both stair-like pattern and mode I fracture surface mode. The obtained surface was finished by colloidal silica suspension to undertake electron back scattered diffraction (EBSD) characterizations at several key positions.
(i) One EBSD acquisition has been operated along an inclined plane (corresponding to Fig. 2(a) of the related Data in Brief).
(ii) One EBSD acquisition has been operated at the transition between the stair-like pattern and the mode I fracture mode (corresponding to Fig. 2(b) of the related Data in Brief).
(iii) One EBSD acquisition has been operated at a location where mode I fracture mode occurs (corresponding to Fig. 2(c) of the related Data in Brief).
For each position, based on the EBSD data (raw files .osc available in the present repository) the local microstructure has been analyzed via crystallographic and geometrical orientation of the primary α- grains.

Furthermore, one particular crack path observed in one "valley" of the stair-like pattern has revealed a kink, such as the local crack path is almost perpendicular to the loading direction, which is an extremely detrimental configuration from the energy viewpoint. An EBSD acquisition of this zone (corresponding to Fig. 3 of the related Data in Brief) has been carried out.

本数据集仓库收集了多类数据，涵盖照片、Matlab可执行脚本、Excel文件以及电子背散射衍射（EBSD）数据集，以全面展示经激光粉末床熔融（L-PBF）工艺制备的新型Ti-6Al-4V基金属基复合材料（MMC）的断裂表面形貌特征。
与未增强的基体合金类似，该增材制造（AM）Ti-6Al-4V合金的宏观断裂表面呈现出清晰的倾斜平面，即所谓的“阶梯状”形貌。换言之，该区域内的裂纹扩展路径并不遵循I型断裂面准则。此外，基于8个不同试样的测试结果，断裂表面上阶梯状形貌的占比介于4.6%至17.6%之间。除阶梯状形貌区域外，断裂表面呈现I型断裂面，并在试样侧缘附近形成剪切唇。

为阐明这一特殊现象的成因，本研究选取一处同时存在阶梯状形貌与I型断裂面的试样进行切片处理。所得试样表面经胶体二氧化硅悬浮液抛光后，在多个关键位置开展了电子背散射衍射（EBSD）表征：
(i) 沿对应于补充数据中图2(a)的倾斜平面进行EBSD采集；
(ii) 在阶梯状形貌与I型断裂模式的过渡区域进行EBSD采集，对应补充数据中的图2(b)；
(iii) 在发生I型断裂的区域进行EBSD采集，对应补充数据中的图2(c)。
针对每个测试位置，本研究基于本仓库中提供的EBSD原始.osc文件，通过初生α晶粒的晶体学与几何取向分析了局部微观组织。

此外，在一处阶梯状形貌的“谷值”区域观察到的特殊裂纹路径存在一处弯折，使得局部裂纹路径几乎垂直于加载方向——从能量角度来看，这是一种极为不利的构型。针对该区域的电子背散射衍射（EBSD）采集已完成，对应补充数据中的图3。