Alloy 718 is a Ni-Fe-based superalloy, which has been successfully adapted to powder bed fusion (PBF) additive manufacturing because of the alloy’s adaptability with such emerging technology in achieving enhanced mechanical properties. Despite a promising perspective for PBF-built Alloy 718 in different industries, a few factors, including microstructural non-uniformities, volumetric defects, undesired non-metallic inclusions, anisotropic behavior, residual stress, as well as surface and sub-surface irregularities, lead to premature fatigue life of the parts. However, the PBF technology has been quickly growing, and associate progress has resulted in substantial advances in quality, hence increased fatigue life of the parts. Therefore, a critical assessment of the efficacy of the PBF-built Alloy 718 parts can be highly enlightening. A fundamental understanding of the relationship between feedstock material, manufacturing process, process parameters, microstructure, properties, and fatigue life of PBF-built Alloy 718 is crucial for improving the characteristics of the current materials, designing new alloy systems, and enhancing the capability of the PBF techniques. The present paper aims to comprehensively review the fundamentals and recent advances in the PBF-built Alloy 718 parts with improved fatigue life, the influence of thermal and mechanical post-treatment, mechanisms of fatigue crack initiation and growth, thermo-mechanical fatigue, dwell-time fatigue, as well as fracture behavior in different loading conditions and environments considering anisotropic characteristics of the material. An unbiased review of the literature provides an understanding of the advanced and outstanding achievements in the field that assure further research. An evaluation of the status of the field, the gaps in the theoretical understanding, and the fundamental needs for the sustainable development of PBF-built Alloy 718 with enhanced fatigue life in specific applications are also provided.

合金 718 是一种 Ni-Fe 基超级合金，由于该合金在实现增强的机械性能方面对此类新兴技术的适应性，已成功适用于粉末床熔融 (PBF) 增材制造。尽管 PBF 合金 718 在不同行业的前景广阔，但一些因素，包括微观结构不均匀性、体积缺陷、不需要的非金属夹杂物、各向异性行为、残余应力以及表面和亚表面不规则性，导致铅零件的过早疲劳寿命。然而，PBF 技术一直在快速发展，相关的进步带来了质量的实质性进步，从而延长了零件的疲劳寿命。因此，对 PBF 制造的合金 718 零件的功效进行批判性评估可能具有很高的启发性。基本了解 PBF 合金 718 的原料材料、制造工艺、工艺参数、微观结构、性能和疲劳寿命之间的关系对于改善当前材料的特性、设计新的合金系统和提高性能至关重要。 PBF技术。本文旨在全面回顾 PBF 制造的合金 718 零件的基本原理和最新进展，疲劳寿命得到改善，热和机械后处理的影响，疲劳裂纹萌生和扩展的机制，热机械疲劳，驻留-时间疲劳，以及考虑材料各向异性特性的不同加载条件和环境下的断裂行为。对文献进行公正的审查可以了解该领域的先进和杰出成就，从而确保进一步研究。还提供了对该领域现状的评估、理论理解的差距，以及 PBF 制造的具有增强疲劳寿命的合金 718 在特定应用中可持续发展的基本需求。