Effect of Size, Location, and Aspect Ratio of Internal Pores on Failure Behavior of Laser Powder Bed Fusion Ti-6Al-4V
Effect of Size, Location, and Aspect Ratio of Internal Pores on Failure Behavior of Laser Powder Bed Fusion Ti-6Al-4V
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DOI：
10.1007/s11837-023-05751-4
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发表时间：
2023-03
期刊：
影响因子：
2.6
通讯作者：
E. Furton;Selda Nayir;A. Beese
中科院分区：
文献类型：
--
作者：
E. Furton;Selda Nayir;A. Beese
采用激光粉末床熔融增材制造技术制备了缺口拉伸Ti-6Al-4V试样。在每个样品的制造过程中，包括单个内部孔，并且其尺寸、纵横比和位置是变化的。孔隙的存在显著降低了样品的延展性，其中孔隙的尺寸和位置是最关键的因素，并且纵横比没有影响。内部孔隙的严重程度用J积分量化，表明断裂发生在23 kN/m的临界值处。韧性断裂模型进行了校准与实验测量的位移失败，并用于量化的位置依赖的损伤累积率。虽然损伤在表面附近开始（这意味着近表面孔隙在早期变形中至关重要），但样品中心处的应力三轴度增加导致相对于中心定位孔隙的施加位移的损伤累积更高。
Notched tension Ti-6Al-4V samples were fabricated using laser powder bed fusion additive manufacturing. During the fabrication of each sample, a single internal pore was included, and its size, aspect ratio, and location were varied. The presence of pores significantly reduced the ductility of the samples, where the size and location of the pores were the most critical factors, in that order, and the aspect ratio was not impactful. The severity of the internal pore was quantified with the J-integral, revealing that fracture occurred at a critical value of 23 kN/m. Ductile fracture models were calibrated with the experimentally measured displacements to failure and used to quantify the location-dependent rate of damage accumulation. Although damage initiated near the surface (meaning that near-surface pores were critical in early deformation), the increased stress triaxiality at the center of the sample led to higher damage accumulation with respect to applied displacement for centrally-located pores.