AS ISO ASTM 52902:2021 pdf free download – Additive manufacturing -Test artifacts -eometric capability assessment of additive manufacturing systems.
This document covers the general description of benchmarking test piece geometries along with quantitative and qualitative measurements to be taken on the benchmarking test piece(s) to assess the performance of additive manufacturing (AM) systems.
This performance assessnient can serve the following two purposes:
— AM system capability evaluation:
— AM system calibration.
The benchinarking test piece(s) is (are) primarily used to quantitatively assess the geometric performance of an AM system. This document describes a suite of test geometries, each designed to investigate one or more specific performance metrics and several example configurations of these geometries into test piece(s). It prescribes quantities and qualities of the test geometries to be measured but does not dictate specific measurement methods. Various userapplicatlons can require various grades of performance. This document discusses examples of feature configurations, as well as measurement uncertainty requirements, to demonstrate low and high grade examination and performance. This document does not discuss a specific procedure or machine settings for manufacturing a test piece. which are covered by ASTM F 2971 and other relevant process specific specifications.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/ASTM 52900, AdditIve manufacturing — General principles — Fundamentals and vocabulasy
ISO/ASTM 52921, Standard terminology for additive manufacturing — Coordinate systems and test methodologies
ASME B46,1, Surface Texture (Surface Roughness, Waviness and Lay)
3 Terms and definitions
For the purposes of this dcumcnt, the terms and definitions given in ISO/ASTM 52900 and ISO/ASTM 52921 apply.
ISO and IEC maintain terminologk-al databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www .orgJobp
— IEC Electropedia: available at http://www.electropedia.org/
4 Significance and use
4.1 General
Measurements and observations described in this document are used to assess the performance of an AM system with a given system set-up and process parameters, in combination with a specific feedstock material.
6 General principles for measuring artifacts
6.1 General
This clause outlines principles applicable for measuring all of the test artifact geometries in this document. The specific measurements are specified in Clause 7 describing the individual artifact geometries. This document does not prescribe any specific measurement methods; the measurements described below can be accomplished by a variety of techniques and devices e.g. coordinate measuring machine, optical scanner, dial indicators with calibrated motion devices, surface profilometers, etc.). ISO 17296-3 can be used to improve communication between stakeholders concerning test methods. Reporting requirements are previewed In connection with the measurement steps in this clause but more details about recording and reporting can be found in Annexes B and C.
6.2 Measure parts as built
The test artifact should be allowed to cod to room temperature and then measured directly after it is removed from the system used to build it, before any post-processing is performed. The end user may require that parts be held at a set temperature and humidity prior to measurement. If the parts are built by a powder bed based process, the parts should be completely separated from the surrounding powder before measurement. If the parts are built on a build platform, perform the measurements without removing the part from the platform. (Removal from a build platform can affect the shapes of the artifacts, thereby Influencing the results, If measurement is not possible on the platlorm. this shall be explicitly stated in the report.) If post-processing is desired, report all details of each post- processing step and measure the part before and after each post-processing steps (reporting all measurement results).
6.3 Measurement strategy
It is well known that measurement strategy affects the overall measurement uncertainty; this is true for dimensional measurements and surface measurements alike. Measurement strategy, here, involves the device chosen to perform the measurement along with the number of points selected to represent the feature or surface and the distribution of points along the feature or surface. For roughness measurements, the measurement strategy includes any applied filters (e.g. the cut-off length). Measurement strategy is a complicated subject and is often very specific to the part or feature being measured, As such, there is no general “best practice” for performing these measurements. However, some tips are provided in Annexes B and C. The measurement uncertainty is ultimately the important concept, and, with consideration given to the available measurement devices, using a measurement strategy that minimizes the measurement uncertainty within any given constraints should be the primary focus.
