AS ISO ASTM 52911.2:2021 Additive manufacturing一Design Part 2: Laser-based powder bed fusion of polymers

AS ISO ASTM 52911.2:2021 Additive manufacturing一Design Part 2: Laser-based powder bed fusion of polymers. This document specifies the features of laser-based powder bed fusion of polymers (LB-PBF/P) and provides detailed design recommendations. Some of the fundamental principles are also applicable to other additive manufacturing (AM) processes, provided that due consideration is given to process-specific features. This document also provides a state-of-the-art review of design guidelines associated with the use of powder bed fusion (PBF) by bringing together relevant knowledge about this process and by extending the scope of ISO/ASTM 52910. 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 vocabulary 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO/ASTM 52900 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https://www .org/obp — IEC Electropedia: available at http://www.electropedia.org/ 3.1 downskin area (sub-)area where the normal vector projection on the z-axis is negative Note ito entry: See Figure 1. 3.2 downskin angle angle between the plane of the build platform and the downskin area (11) Note 1 to entry: The angle lies between 00 (parallel to the build platform) and 900 (perpendicular to the build platform). Note 2 to entry: See Figure 1. 3.3 upskin area U (sub-)area where the normal vector n projection on the z-axis is positive Note I to entry: See Figure 1. 5.2 Size of the parts The size of the parts is limited by the working area/working volume of the PB F-machine. Also, the occurrence of cracks and deformation due to residual stresses limits the maximum part size. Another important practical factor that limits the maximum part size is the cost of production having a direct relation to the size and volume of the part. Cost of production can be minimized by choosing part location and build orientation in a way that allows nesting of as many parts as possible. Also, the cost of powder needed to fill the bed to the required volume (part depth x bed area) may be a...