ASTM F3637-23 PDF

SIGNIFICANCE AND USE 5.1 General: 5.1.1 This guide is intended to support PBF-LB process and parameter development, part acceptance criteria, and process control tests. 5.1.2 Flaws and Defects-Fabricating fully dense parts continues to be a challenge in AM as the process intrinsically introduces volumetric flaws into a part reducing the part relative density (that is, increasing porosity or the presence of small voids in a part making it less than fully dense) and mechanical performance. 5.1.2.1 When a flaw reaches a size, shape, location, or criticality that makes it becomes unacceptable for part acceptance, it will be referred to as a defect. 5.1.2.2 Flaw or defect formation is governed by the manufacturing process, build parameters, feedstock, and geometric factors. Therefore, accurate measurement of fabricated part relative density is an important initial step in determining part and process quality. 5.1.2.3 The quantity, size, and shape of the volumetric flaws influences mechanical performance of a part, particularly under cyclic loading. These data could indicate irregularly shaped (for example, LOF pores or microcracking) or spherical porosity (for example, keyhole or entrapped gas porosity) and determine acceptability by assigning criteria. While these metrics can be quantified, in this guide, the general capabilities of each method to capture this data will be highlighted, but detailed recommendations on these data types will not be made and rather the focus will be on relative density measurements. 5.1.3 Uncertainty and Error-Users should consider that each measurement technique considered in this guide has differing sensitivities to various sized features. The measurement methods will also have different potential systematic errors or measurement uncertainties due to sampling sizes, detection resolution, effect of surface condition, experimental set-up, or reliance on a theoretical material density. It is important that these effects are taken into considerati... SCOPE 1.1 In this standard, guidelines for measuring post-manufacturing relative density of metallic additive manufactured (AM) parts and density assessment test specimens are given. 1.2 In this guide, standard test methods commonly used to measure part relative density and details any procedural changes or recommendations for use with PBF-LB parts are referenced. Extensibility to other types of metallic AM processes may be considered on a case-by-case basis with user discretion. 1.3 This guide is intended to be applied during the selection process of methods to measure the relative density of AM parts to balance cost, accuracy, complexity, part destruction, and part size concerns. 1.4 Pore size, shape, and distribution and their implications relative to the AM process and material are beyond the scope of this guide; however, each method’s ability to obtain these metrics is discussed in the context of the various density measurement methods. 1.5 Units-The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. 1.6 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. 1.7 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.