1.1 本指南讨论了用于检查由增材制造（AM）制成的金属零件的既定和新兴无损检测（NDT）程序的使用。 1.2 所涵盖的无损检测程序产生的数据与微观结构、零件几何形状、零件复杂度、表面光洁度和使用的不同AM工艺有关，并受其影响。 1.3 按照本指南所述程序测试的零件用于航空航天应用；因此，与非航空航天应用中使用的材料和部件相比，不连续性和检查点的检查要求通常不同且更严格。 1.4 正在考虑的金属材料包括但不限于铝合金、钛合金、镍基合金、钴铬合金和不锈钢。 1.5 考虑的制造过程使用粉末和线材原料，以及激光或电子能源。 讨论了特定的粉末床熔合（PBF）和定向能沉积（DED）工艺。 1.6 本指南讨论了零件制造后的无损检测。零件将以三种可能状态之一存在: (1) 后处理（热处理、热等静压、机加工等）前的原始、竣工零件， (2) 中间加工零件，或 (3) 所有后处理完成后的成品零件。 1.7 本指南中讨论的无损检测程序由认可的工程组织用于检测竣工（原始）和后处理（成品）零件中的表面和体积缺陷。 1.8 本指南中讨论的无损检测程序为计算机断层扫描（CT，第 7. ，包括微焦点CT），涡流检测（ET，第 8. )，光学计量（MET，第节 9 )渗透检测（PT，第 10 )，过程补偿谐振测试（PCRT，第节 11 )，射线检测（RT，第 12 )，红外热成像（IRT，第 13 )和超声波检测（UT，第 14 ). 本指南不包括其他无损检测程序，如泄漏检测（LT）和磁粉检测（MT），这些程序已知可用于AM零件的检查。 1.9 本指南不包括构建过程中的过程监控实践和指南，包括传感器选择和过程质量保证指南。 1.10 本指南主要基于ASTM E07无损检测委员会管辖下的既定程序，由相应的小组委员会直接负责。 1.11 本指南不建议对AM零件应用无损检测的具体行动方案。 旨在从无损检测角度提高对既定无损检测程序的认识。 1.12 有关输入材料控制、工艺设备校准、制造工艺和后处理的建议不在本指南的范围内，由ASTM F42委员会添加剂制造技术委员会管辖。尽可能遵循ASTM F42或同等标准管辖下的标准，以确保制造出适合无损检测的可复制零件。 1.13 有关断裂关键AM零件的检查要求和管理的建议超出了本指南的范围。有关疲劳、断裂力学和断裂控制的建议见相应的最终用户需求文件，以及ASTM委员会E08关于疲劳和断裂的管辖标准。 注1: 要使用破坏性试验确定由添加剂制造的金属零件的变形和疲劳性能，请参阅指南 F3122 . 注2: 为了量化与断裂关键AM零件相关的风险，结构评估团体（如ASTM疲劳和断裂委员会E08）有义务定义零件的临界初始缺陷尺寸（CIFS），以定义无损检测的目标。 1.14 本指南未规定采购中使用的验收和拒收标准，也未规定验收和拒收标准是批准AM零件用于服务的一种方法。任何接受-拒绝标准仅供说明和比较之用。 1.15 单位- 以国际单位制表示的数值应视为标准值。国际单位制后括号中给出的值仅供参考，不被视为标准值。 1.16 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.17 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 通过增材制造制造的金属零件不同于通过锻造、铸造或焊接制造的传统金属零件。增材制造会产生相互熔化或烧结的层。 零件的形状由计算机和层控制。计算机将激光或电子束的能量引导到粉末床或导线输入材料上。这些处理方法有可能在竣工或成品零件中产生不需要的缺陷。一般来说，构建过程中的处理参数异常和中断可能会导致此类“缺陷”由于输入材料中存在污染物，也可能引入缺陷。 4.2 ASTM E07标准中给出的既定无损检测程序是本指南中讨论的无损检测程序的基础。这些无损检测程序用于在后处理或精加工操作之前或之后，或在最终用户在安装之前收到成品零件之后，检查生产零件。本指南中描述的无损检测程序基于为传统制造的铸造、锻造或焊接生产零件制定的程序。 4.3 本指南中讨论的无损检测程序的应用旨在降低材料或部件故障的可能性，从而减轻或消除与功能丧失相关的伴随风险，并可能减少地面支持人员、机组人员或任务的损失。 4.4 输入材料- 本指南涵盖的输入材料包括但不限于由铝合金、钛合金、镍基合金、钴铬合金和不锈钢制成的材料。输入材料为粉末或金属丝。 注3: 当使用电子束时，电子束与任何导电材料有效耦合，包括铝和铜基合金。 4.4.1 粉末- AM工艺所需的高质量粉末由 (1) 等离子体雾化， (2) 惰性气体雾化，或 (3) 旋转电极离心雾化( 图1 ). （A） 使用的缩写:…=未知或不适用，CAD=计算机辅助设计，CMM=坐标测量机，CT=计算机断层扫描，DED=定向能量沉积，EBM=电子束熔化，ET=涡流测试，EMF=电磁频率，HIP=热等静压，IRT=红外热成像，LOF=未熔合，MET=光学计量，PA=等离子弧，PBF=粉末床熔合，PCRT=过程补偿共振检测，PT=渗透检测，SLM=选择性激光熔化，UT=超声波检测。 （B） 表格部分由AMAZE FP7项目提供。 （C） NDT检测到的不连续或缺陷不一定是可拒收的。 （D） 由于快速淬火，这也可能导致亚稳或非平衡形态。 （E） 在长构建期间出现问题。 （F） ISO TC 261 JG59 N 237指南。 （G） 如果是表面或近表面。 注15: 焊缝和铸件有长期的无损检测标准缺陷类别。通常，焊接和铸造零件的缺陷类别不同于AM零件的缺陷类别。 4.9 工艺缺陷相关性- 鉴于金属添加剂制造中遇到的材料和工艺范围，仍在确定缺陷的工艺来源。然而，存在一些例子。例如，当能量输入不足时，连续扫描轨迹不能正确融合在一起，沿着扫描线出现缺陷。在L-PBF零件中，与能量输入不足相关的不完全润湿和成球效应已被证明会导致气孔或空洞。此外，如果未仔细选择工艺参数，EB-PBF零件可能会出现跨越多层的大空隙或空腔。 由于最初存在气体雾化金属粉末的气体夹带，电子束加工零件中也会形成较小的球形孔。 4.10 缺陷特性相关性- 与缺陷较少的零件相比，具有缺陷的零件，例如孔隙度、LOF、跳过层、停止/启动缺陷、夹杂物或过度表面粗糙度，可能会表现出强度和疲劳性能下降。此外，公认的做法是在进行无损检测之前识别经历主应力的区域，以评估这些区域中任何检测到的缺陷的潜在影响。除了缺陷类型、尺寸和位置外，其他缺陷特征可能也相关，例如数量、总体积、缺陷/长度（纵横比）、方向和平均近邻距离以及与表面的接近度。 （A） 使用的缩写:DED=定向能量沉积，HAZ=热影响区，HIP=热等静压 （A） 使用的缩写:…=不适用，AE=声发射，CR=计算机射线照相，CT=计算机断层扫描，DR=数字放射学，ET=涡流检测，IRT=红外热成像，LT=泄漏检测，MET=计量，MT=磁粉检测，NR=中子射线照相，PCRT=过程补偿共振检测，PT=渗透检测，RT=射线照相检测，UT=超声波检测，VT=目视检测。 （B） 包括数字成像。 （C） 在描述内部通道或空腔（复杂几何形状零件）的特征时特别有用，以用于填充不足和填充过度，或MET、PT或VT无法访问的其他内部特征（包括孔镜检查）。 （D） 适用于表面。 （E） 射线照相方法不是检测紧密层流特征的最佳方法，例如裂纹和LOF，其通常不会表现出足够的密度变化。 （F） 如果足够大，导致零件泄漏或压降。 （G） 仅宏观裂纹。 （H） 常规中子照相术（NR）允许确定内部和外部尺寸。 （一） 比重瓶法（阿基米德原理）。 （J） 密度变化只会出现在具有等效厚度的成像区域中。 （K） 如果夹杂物足够大且存在足够的散射对比度。 （L） 如果残余应力是由表面后处理（例如，喷丸）引起的，则可以对其进行评估。

1.1 This guide discusses the use of established and emerging nondestructive testing (NDT) procedures used to inspect metal parts made by additive manufacturing (AM). 1.2 The NDT procedures covered produce data related to and affected by microstructure, part geometry, part complexity, surface finish, and the different AM processes used. 1.3 The parts tested by the procedures covered in this guide are used in aerospace applications; therefore, the inspection requirements for discontinuities and inspection points in general are different and more stringent than for materials and components used in non-aerospace applications. 1.4 The metal materials under consideration include, but are not limited to, aluminum alloys, titanium alloys, nickel-based alloys, cobalt-chromium alloys, and stainless steels. 1.5 The manufacturing processes considered use powder and wire feedstock, and laser or electron energy sources. Specific powder bed fusion (PBF) and directed energy deposition (DED) processes are discussed. 1.6 This guide discusses NDT of parts after they have been fabricated. Parts will exist in one of three possible states: (1) raw, as-built parts before post-processing (heat treating, hot isostatic pressing, machining, etc.), (2) intermediately machined parts, or (3) finished parts after all post-processing is completed. 1.7 The NDT procedures discussed in this guide are used by cognizant engineering organizations to detect both surface and volumetric flaws in as-built (raw) and post-processed (finished) parts. 1.8 The NDT procedures discussed in this guide are computed tomography (CT, Section 7 , including microfocus CT), eddy current testing (ET, Section 8 ), optical metrology (MET, Section 9 ), penetrant testing (PT, Section 10 ), process compensated resonance testing (PCRT, Section 11 ), radiographic testing (RT, Section 12 ), infrared thermography (IRT, Section 13 ), and ultrasonic testing (UT, Section 14 ). Other NDT procedures such as leak testing (LT) and magnetic particle testing (MT), which have known utility for inspection of AM parts, are not covered in this guide. 1.9 Practices and guidance for in-process monitoring during the build, including guidance on sensor selection and in-process quality assurance, are not covered in this guide. 1.10 This guide is based largely on established procedures under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of the appropriate subcommittee therein. 1.11 This guide does not recommend a specific course of action for application of NDT to AM parts. It is intended to increase the awareness of established NDT procedures from the NDT perspective. 1.12 Recommendations about the control of input materials, process equipment calibration, manufacturing processes, and post-processing are beyond the scope of this guide and are under the jurisdiction of ASTM Committee F42 on Additive Manufacturing Technologies. Standards under the jurisdiction of ASTM F42 or equivalent are followed whenever possible to ensure reproducible parts suitable for NDT are made. 1.13 Recommendations about the inspection requirements and management of fracture critical AM parts are beyond the scope of this guide. Recommendations on fatigue, fracture mechanics, and fracture control are found in appropriate end user requirements documents, and in standards under the jurisdiction of ASTM Committee E08 on Fatigue and Fracture. Note 1: To determine the deformation and fatigue properties of metal parts made by additive manufacturing using destructive tests, consult Guide F3122 . Note 2: To quantify the risks associated with fracture critical AM parts, it is incumbent upon the structural assessment community, such as ASTM Committee E08 on Fatigue and Fracture, to define critical initial flaw sizes (CIFS) for the part to define the objectives of the NDT. 1.14 This guide does not specify accept-reject criteria used in procurement or as a means for approval of AM parts for service. Any accept-reject criteria are given solely for purposes of illustration and comparison. 1.15 Units— The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.16 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.17 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 Metal parts made by additive manufacturing differ from their traditional metal counterparts made by forging, casting, or welding. Additive manufacturing produces layers melted or sintered on top of each other. The part’s shape is controlled by a computer as well as by the layers. The computer directs energy from a laser or electron beam onto a powder bed or wire input material. These processing approaches have the potential of creating flaws that are undesirable in the as-built or finished part. In general, processing parameter anomalies and disruptions during a build may induce such “flaws.” Flaws can also be introduced because of contaminants present in the input material. 4.2 Established NDT procedures such as those given in ASTM E07 standards are the basis for the NDT procedures discussed in this guide. These NDT procedures are used to inspect production parts before or after post-processing or finishing operations, or after receipt of finished parts by the end user prior to installation. The NDT procedures described in this guide are based on procedures developed for conventionally manufactured cast, wrought, or welded production parts. 4.3 Application of the NDT procedures discussed in this guide is intended to reduce the likelihood of material or component failure, thus mitigating or eliminating the attendant risks associated with loss of function, and possibly, the loss of ground support personnel, crew, or mission. 4.4 Input Materials— The input materials covered in this guide consist of, but are not limited to, ones made from aluminum alloys, titanium alloys, nickel-based alloys, cobalt-chromium alloys, and stainless steels. Input materials are either powders or wire. Note 3: When electron beams are used, the beam couples effectively with any electrically conductive material, including aluminum and copper-based alloys. 4.4.1 Powders— High-quality powders required for AM process are produced by (1) plasma atomization, (2) inert gas atomization, or (3) centrifugal atomization using rotating electrodes ( Fig. 1 ). (A) Abbreviations used: … = unknown or not applicable, CAD = computer aided design, CMM = coordinate measuring machine, CT = computed tomography, DED = directed energy deposition, EBM = electron beam melting, ET = eddy current testing, EMF = electromagnetic frequency, HIP = hot isostatic pressing, IRT = irfrared thermography, LOF = lack of fusion, MET = optical metrology, PA = plasma arc, PBF = powder bed fusion, PCRT = process compensated resonance testing, PT = penetrant testing, SLM = selective laser melting, and UT = ultrasonic testing. (B) Portions of table courtesy of AMAZE FP7 project. (C) Discontinuities or indications detected by NDT that are not necessarily rejectable. (D) Due to rapidly quenching, which may also lead to metastable or nonequilibrium morphologies. (E) Issue during long builds. (F) ISO TC 261 JG59 N 237 Guide. (G) If surface or near surface. Note 15: There are longstanding NDT standard flaw classes for welds and castings. In general, the defect classes for welded and cast parts differ from the flaw classes for AM parts. 4.9 Process-Flaw Correlation— Given the range of materials and processes encountered in metal additive manufacturing, the process origins of flaws are still being characterized. However, examples exist. For example, when the energy input is insufficient, successive scan tracks do not properly fuse together and flaws appear along the scan line. In L-PBF parts, incomplete wetting and balling effects associated with insufficient energy input have been shown to lead to pores or voids. In addition, EB-PBF parts can show large voids or cavities extending across several layers when the process parameters are not carefully chosen. Smaller spherical pores can also develop in EBM parts due to entrapment of gases originally present gas-atomized metal powders. 4.10 Flaw-Property Correlation— Parts with flaws, for example, porosity, LOF, skipped layers, stop/start flaws, inclusions, or excessive surface roughness, can exhibit degraded strength and fatigue properties compared with parts with fewer flaws. Furthermore, it is accepted practice to identify regions experiencing principle stresses before NDT is performed to assess the potential effect of any detected flaws in those regions. In addition to flaw type, size, and location, other flaw characteristics may be relevant, such as number, total volume, flaw/length (aspect ratio), orientation, and average nearest neighbor distance, and proximity to surfaces. (A) Abbreviations used: DED = Directed Energy Deposition, HAZ = Heat Affected Zone, HIP = Hot Isostatic Pressing (A) Abbreviations used: … = not applicable, AE = Acoustic Emission, CR = Computed Radiography, CT = Computed Tomography, DR = Digital Radiology, ET = Eddy Current Testing, IRT = Infrared Thermography, LT = Leak Testing, MET = Metrology, MT = Magnetic Particle Testing, NR = Neutron Radiography, PCRT = Process Compensated Resonance Testing, PT = Penetrant Testing, RT = Radiographic Testing, UT = Ultrasonic Testing, and VT = Visual Testing. (B) Includes Digital Imaging. (C) Especially helpful when characterizing internal passageways or cavities (complex geometry parts) for underfill and overfill, or other internal features not accessible to MET, PT, or VT (including borescopy). (D) Applicable if on surface. (E) Radiographic methods are not optimal for detecting tight laminar features like cracking and LOF, which typically do not exhibit enough density change. (F) If large enough to cause a leak or pressure drop across the part. (G) Macroscopic cracks only. (H) Conventional neutron radiography (NR) allows determination of internal and external dimensions. (I) Pycnometry (Archimedes principle). (J) Density variations will only show up in imaged regions having equivalent thickness. (K) If inclusions are large enough and sufficient scattering contrast exists. (L) Residual stress can be assessed if resulting from surface post-processing (for example, peening).