ISO ASTM 52903-2:2020 pdf free.Additive manufacturing -Material extrusion-based additive manufacturing of plastic materials -Process equipment.
4 Process specification
4.1 General
According to the final quality of the part, the process may be classified under the following classes:
4.2 Class I Process specification: most rigorous process specification intended for use in producing the highest quality parts with the highest degree of confidence through detailed traceability required in quality documents.
4.3 Class II . Process specification: a rigorous process specification intended for use in producing high quality parts with less traceability than Class I.
4.4 Class III Process specification: a general process specification intended for use as a guideline in processing quality parts using best practice with minimum traceability.
NOTE These classes are referenced from the powder bed fusion document ASTM F3091.
5 Materials
Materials shall be in accordance with ISO/ASTM 52903-1.
6 Fabrication of test specimens
6.1 General
Unless otherwise specified by the customer, all test specimens shall be additive manufactured parts which are not post-processed, with the exception of removing support material.
Since post-processing can affect some final part properties, the customer should consider evaluating test specimens with the same post processing as the one that the final parts have or are expected to have.
6.2 Direction-independent properties
Test specimens used to assess direction-independent properties may be built with associated parts anywhere in the build envelope at the part manufacturer’s discretion. Unless otherwise specified by the customer or the specific test method to be employed, a minimum of three test specimens for each property per build shall be evaluated. The specimens may be aligned to any directional axis (X, Y, or Z) chosen by the part manufacturer.
6.3 Non-mechanical direction-dependent properties
Unless otherwise specified by the customer, test specimens used to assess non-mechanical, potentially direction-dependent properties such as electrical resistance shall be built in a location and direction deemed by the part manufacturer to be the least favourable orientation (ISO/ASTM 52921) within the master bounding box (ISO/ASTM 52900) for measurement of the property in question. Unless otherwise specified by the customer or the specific test method to be employed, a minimum of three test specimens per build shall be evaluated.
64 Mechanical direction-dependent properties
6.4.1 All mechanical property testing except tension testing
Unless otherwise specified by the customer, test specimens other than tension testing specimens used to assess mechanical properties such as flexural modulus, impact strength and shear modulus shall be built in a location and direction deemed by the part manufacturer to be the least favourable
orientation (ISO/ASTM 52921) within the master bounding box (JSO/ASTM 52900) for measurement of the property in question. Unless otherwise specified by the customer or the specific test method to be employed, three test specimens per build shall be evaluated.
6.4.2 Tension testing
Unless otherwise specified by the customer, the number, orientation and location of test specimens for evaluation of tensile mechanical properties shall be as specified in Table 1.
7 Responsibility for quality assurance (inspection and test)
Unless otherwise specified in the contract or purchase order, the part manufacturer is responsible for the execution of all inspection and testing specified herein. Unless otherwise directed by the customer in the order, the part manufacturer may use their own or any other suitable facilities for the performance of the inspection and test requirements specified herein. The customer shall have the right to perform any inspection and testing set forth in the specification where such inspections are deemed necessary to assure that material conforms to prescribed requirements.
8 Tolerances and surface roughness
Tolerances, given in absolute or relative format, and surface roughness shall be defined by the customer in consultation with the part manufacturer.
9 Material processing
9.1 Maintenance
9.1.1 The additive manufacturing equipment shall be cleaned in accordance with the original equipment manufacturer’s instructions and/or recommendations along with the part manufacturer’s best practice prior to each build.
9.1.2 Special consideration shall be given to cleaning and maintaining the extrusion nozzle tip according to the manufacturer’s specifications.ISO ASTM 52903-2 pdf download.