GB/T 42618-2023Additive manufacturing - Design - Laser-based powder bed fusion of polymers (English PDF)

Foreword

This document was issued on 23 May 2023 by the State Administration for Market Regulation; Standardization Administration of the PRC and takes effect on 1 December 2023.

It is a GB/T standard: recommended rather than compulsory, but it is the text a Chinese reviewer applies when assessing a submission.

It is classified under ICS 25.030, Chinese classification J04.

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1. Structure and Drafting Rules for Standardization Documents"

drafting.

This document is modified to adopt ISO /ASTM52911-2.2019 "Design for Additive Manufacturing Part 2. Laser Powder Bed of Polymer Materials"

Melt.

Compared with ISO /ASTM52911-2.2019, this document has made the following structural adjustments.

---Chapter 5 corresponds to Chapter 5 in ISO /ASTM52911-2.2019, of which 5.1~5.7 corresponds to ISO /ASTM52911-2.

5.2~5.8 in.2019, deleted 5.1 in ISO /ASTM52911-2.2019;

---Chapter 6 and Appendix A correspond to Chapter 6 in ISO /ASTM52911-2.2019, of which 6.1~6.6 correspond to ISO /ASTM

6.2~6.7 in 52911-2.2019, Appendix A corresponds to 6.8 in ISO /ASTM52911-2.2019, appendix is added

A, Deleted 6.1 in ISO /ASTM52911-2.2019.

The technical differences between this document and ISO /ASTM52911-2.2019 and their reasons are as follows.

--- Replaced ISO /ASTM52900 (see Chapter 3) with the normatively quoted GB/T 35351 to continue to use my country's additive manufacturing

Domain terms are defined in a customary way for ease of use;

--- Added the term "secondary sintering" (see 3.5) to unify the industry terms;

--- Deleted the introductory content of Chapter 5.1, 6.1 and Chapter 8 in ISO /ASTM52911-2.2019, and the background introduction does not need to be repeated;

--- An example of a typical complex geometric structure (see 5.2) has been added to adapt to the development of additive manufacturing technology;

--- Deleted the non-typical free geometry, topology optimization structure and filling structure in 5.3 of ISO /ASTM52911-1.2019

Examples or meanings, free geometry, topology optimization structures and infill structures are already examples and very clear, no need to give

Give detailed examples;

---Changed the impact of product height on the positioning method and changed it to "should" (see 5.4), because although the impact of height is the largest, it is not necessary

required;

---Introduction to the process of converting DICOM files to 3D geometric models (see 5.7) has been added to make the process smoother;

--- Increased the relevant content of preheating temperature, including semi-crystalline polymer and amorphous polymer PBF (see 6.1), to improve this document

operability;

---Changed the main performance and abbreviation code of LB-PBF/P raw materials (see Table 2), expanded the performance description, and improved the operability of this document

active;

--- Delete the last sentence of 6.3 in ISO /ASTM52911-2.2019 to adapt to the current status of additive manufacturing technology;

--- Added GB/T 41507 (see 6.3.1) for normative references, because the text is a required clause;

--- Deleted the recommended content of font size and type in 6.7.13 inscription printing in ISO /ASTM52911-2.2019 to adapt to

The development of new technologies for additive manufacturing, such as micro-selection printing.

The following editorial changes have been made to this document.

--- In order to coordinate with existing standards, change the name of the standard to "Design of Additive Manufacturing and Laser Powder Bed Fusion of Polymer Materials";

---Delete the informative references to 3.4, 5.6.2, 5.6.4, 6.3, 6.7.6, 6.7.10 in ISO /ASTM52911-2.2019 Germany

Standard VDI3405, to avoid copyright issues;

---Added the abbreviations "3D" and "2.5D", changed the abbreviations "LB-PBF/P" and

Another name for "STL"; Deleted the electron beam metal PBF in 4.2 of ISO /ASTM52911-2.2019 which is not relevant to this document

and the related abbreviations "EB-PBF/M" and "LB-PBF/M" for laser metal PBF (see 4.2);

--- Increase the relevant content of the design guide, replace ISO /ASTM52910 with the informative reference GB/T 37698 (see 5.6);

--- Added the relevant content of the file format, and replaced ISO /ASTM52915 with the informative reference GB/T 35352

(see 5.7);

---Delete descriptive sentences such as the pressurization principle of the inner runner in 6.7.6 of ISO /ASTM52911-2.2019;

---Deleted the application case of 6.8 in ISO /ASTM52911-2.2019, and added the application case of my country (see Appendix A).

Please note that some contents of this document may refer to patents. The issuing agency of this document assumes no responsibility for identifying patents.

This document is proposed by China Machinery Industry Federation.

This document is under the jurisdiction of the National Additive Manufacturing Standardization Technical Committee (SAC/TC562).

This document was drafted by. Anhui Spring Valley 3D Printing Intelligent Equipment Industrial Technology Research Institute Co., Ltd., Shandong Chuangrui Laser Technology Co., Ltd.

Company, Huazhong University of Science and Technology, Beijing Xinghang Electromechanical Equipment Co., Ltd., China Academy of Mechanical Sciences Group Co., Ltd., China Ocean University

Science, China Machine Research Institute of Standard Technology (Beijing) Co., Ltd., Beijing Institute of Technology, China Machine Productivity Promotion Center Co., Ltd., Shanghai Materials Research Institute

Research Institute, Beijing Remote Sensing Equipment Research Institute, Beijing Huitianwei Technology Co., Ltd., China Commercial Aircraft Co., Ltd. Beijing Civil Aircraft Technology

Research Center, China Aviation Development Shanghai Commercial Aviation Engine Manufacturing Co., Ltd.

The main drafters of this document. Wu Poor, Lu Zhongli, Yan Chunze, Li Zhiyong, Zhu Zheng, Liu Yonghui, Xue Lian, Zhao Zeang, Bian Chen, Li Haibin, Hu Hao,

Wang Geng, Shang Peng, Wang Yu, Hou Huipeng, Zhang Xiaolu.

Introduction

Polymer material laser powder bed fusion process (LB-PBF/P) is a kind of non-metallic additive manufacturing process, which has been widely used in aviation

Aerospace, automotive, medical and other fields. LB-PBF/P has a high material utilization rate and does not need supports, which can shorten the product cycle and reduce production costs.

Now the structurally complex components are integrally formed. Due to the diversity of forming materials, it is determined that the LB-PBF/P process can be formed with different characteristics and full

Various types of parts for different purposes. For example, shaped plastic mobile phone casings can be used for structural verification and functional testing, and can also be directly used as parts

Use. to make investment molds or sand molds (cores) for complex casting, to assist the rapid manufacture of complex castings; to manufacture polymer parts with complex structures, as a function

It can be used in parts, and the precision can reach 100mm+/-0.2mm, which is equivalent to the precision casting process.

LB-PBF/P uses the thermal effect of high-energy laser beams to soften or melt powder materials, and then bond them layer by layer to obtain three-dimensional solid parts.

The fused powder, by mixing with the original powder, can be recycled in the subsequent forming process. Commonly used materials include PA12, PA

11, etc. In addition, the material can be filled or mixed with other materials (such as glass-filled PA12 and flame-retardant PA11), thereby improving strength,

Thermal properties, electrical properties and flame retardant properties.

LB-PBF/P process is different from the traditional manufacturing process (such as subtractive material, equal material manufacturing), the problems considered in the design stage are different. LB-

PBF/P has no restrictions similar to the traditional process, which provides designers and manufacturers with a high degree of freedom, but it also needs to understand the manufacturability of the process.

creativity and limitations.

This document describes the process characteristics and design criteria for laser powder bed fusion of polymer materials

Fusion design provides guidance and methods to help designers and producers determine the design elements and give full play to the advantages of the process, and grasp the additive manufacturing process.

The key to product design, improve the quality and performance of additive manufacturing products, and promote the development of additive manufacturing industry in a more orderly, reasonable and economical direction.

It has good economic and social benefits.

Additive ManufacturingDesigning Polymer Materials

Laser Powder Bed Fusion

1 Scope

GB/T 42618-2023 covers the design of parts that will be produced by laser powder bed fusion in polymer, so that the shape drawn is one the process can actually build. Clause 5 sets out the process characteristics the designer works within: part size, the advantages of the powder bed fusion process, its limitations, economy and efficiency, functional constraints, accuracy of size, shape and position, and the data quality, resolution and representation of the model itself. Clause 6 gives the design guidelines — material and structural properties, anisotropy of the material, forming direction, position and arrangement in the build, surface roughness, post-processing, and the remaining design concerns — and an informative annex works through an application case. The introduction explains the pull toward the process: high material utilization, no need for supports, shorter product cycles, lower production cost, and structurally complex components formed in one piece. Those gains only survive if the design accounts for how the part will be oriented and for the fact that the material does not behave the same way along every axis, both of them decisions taken at the drawing stage that no later operation can undo. A modified adoption of ISO/ASTM 52911-2:2019, for design engineers, service bureaux and their customers.

This document specifies the process characteristics and design criteria for laser powder bed fusion of polymeric materials.

This document is applicable to the design of laser powder bed fusion process for polymer materials.

2 Normative references

The contents of the following documents constitute the essential provisions of this document through normative references in the text. Among them, dated references

For documents, only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to

this document.

GB/T 35351 Additive Manufacturing Terminology

GB/T 41507 Additive manufacturing term coordinate system and test method (GB/T 41507-2022, ISO /ASTM52921.

2013, MOD)

3 Terms and Definitions

The following terms and definitions defined in GB/T 35351 apply to this document.

3.1

lower surface area downskinarea

The (sub)region in which the normal vector .n on the z-axis is projected to be negative.

Note. See Figure 1.

3.2

lower surface angle downskinangle

angle between the plane of the forming platform and the lower surface area (3.1).

Note. See Figure 1.

3.3

upper surface area upskinarea

The (sub)region where the normal vector .n on the z-axis is projected to be positive.

Note. See Figure 1.

3.4

upper surface angle upskinangle

angle between the plane of the forming platform and the upper surface area (3.3).