Process-controlled crystallinity in PA12 produced by Multi Jet Fusion and hot pressing: Tailoring cooling profiles to enhance fatigue resistance
Source abstract
Abstract
This work investigates the role of manufacturing-induced crystallinity on the fatigue behavior of Polyamide 12 (PA12), with particular emphasis on the role of temperature in fatigue performance. Specimens produced by Multi Jet Fusion (MJF) are compared with hot-pressed (HP) counterparts manufactured from the same powder batch under controlled cooling conditions. An extended cooling (EC) protocol is introduced to tailor crystallinity by prolonging the residence time within the crystallization window. Comprehensive thermal, microstructural, and mechanical characterization is combined with fatigue testing and in-situ infrared thermography. Results show that higher crystallinity significantly reduces viscoelastic dissipation and self-heating, leading to improved fatigue resistance. Despite lower defect content, standard HP specimens exhibit inferior fatigue performance compared to MJF due to reduced crystallinity. The EC protocol effectively bridges this gap, enhancing fatigue life and matching the MJF fatigue performance. Based on these findings, optimized cooling parameters are proposed and experimentally validated, demonstrating that crystallinity control is an effective process-level strategy to improve the fatigue performance of PA12.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Additive Manufacturing Materials and Processes · Microstructure and mechanical properties · Aluminum Alloy Microstructure Properties
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (49)
Show source-provided references
1. A review of aging, degradation, and reusability of PA12 powders in selective laser sintering additive manufacturing
2. Innovative approaches to 3D printing of PA12 forearm orthoses: a comprehensive analysis of mechanical properties and production efficiency10.3390/ma17030663 ↗
3. A review on polymeric materials in additive manufacturing10.1016/j.matpr.2021.02.485 ↗
4. Comparative characterization of hot-pressed polyamide 11 and 12: mechanical, thermal and durability properties10.3390/polym13203553 ↗
5. Investigating secondary crystallisation of polyamide-12 using fast scanning calorimetry10.1016/j.tca.2025.179948 ↗
6. Enhancing joint efficiency in friction stir welding of PA66 using an induction-heated threaded pin and glass fiber reinforcement10.1016/j.jmrt.2025.06.193 ↗
7. Development of process efficiency maps for selective laser sintering of polymeric composite powders: modeling and experimental testing10.1016/j.jmatprotec.2017.11.027 ↗
8. Tribological and mechanical properties of MoS2 enhanced polyamide 12 for selective laser sintering10.1016/j.jmatprotec.2018.09.026 ↗
9. Selective laser sintering and multi jet fusion: process-induced modification of the raw materials and analyses of parts performance
10. Effects of pressure and cooling rates on crystallization behavior and morphology of isotactic polypropylene10.3390/cryst13060922 ↗
11. Fatigue of polymers10.1007/BF02265215 ↗
12. Cyclic stress fatigue and thermal softening failure of a thermoplastic10.1007/BF00554752 ↗
13. High cycle fatigue properties of selective laser sintered parts in polyamide 1210.1016/j.cirp.2014.03.060 ↗
14. Jyotishkumar · 2023
15. Static and fatigue behavior in presence of notches for polyamide 12 (PA12) additively manufactured via multi jet FusionTM process10.1016/j.ijfatigue.2022.106912 ↗
16. Crystal transition and thermal behavior of nylon 1210.1515/epoly-2020-0039 ↗
17. Crystallization kinetics of polyamide 12 during selective laser sintering10.3390/polym10020168 ↗
18. Non-isothermal crystallization behaviour of polyamide 12 analogous to multi-jet fusion additive manufacturing process10.1016/j.polymer.2021.124256 ↗
19. Effects of build positions on the thermal history, crystallization, and mechanical properties of polyamide 12 parts printed by multi jet fusion10.1080/17452759.2022.2046478 ↗
20. In-depth comparison of polyamide 12 parts manufactured by multi jet fusion and selective laser sintering
21. Comparative study on 3D printing of polyamide 12 by selective laser sintering and multi jet fusion10.1016/j.jmatprotec.2020.116882 ↗
22. Fatigue life prediction of multi jet fusion-manufactured polyamide12 lattice structures using the average strain energy density method10.1016/j.ijfatigue.2025.109452 ↗
23. On the difference in material structure and fatigue properties of nylon specimens produced by injection molding and selective laser sintering10.1016/j.polymertesting.2013.04.014 ↗
24. Mechanical and fatigue behaviour of polyamide 12 processed via injection moulding and selective laser sintering. Analysis based on Kitagawa-Takahashi diagrams10.1016/j.engfracmech.2022.108825 ↗
25. Crystallinity of neat and carbon fiber-reinforced polyamide-6 processed at different cooling rates10.1016/j.compositesa.2024.108520 ↗
26. More than 25 years of extreme value statistics for defects: fundamentals, historical developments, recent applications10.1016/j.ijfatigue.2021.106407 ↗
27. Understanding thermal aging of non-stabilized and stabilized polyamide 12 using 1H solid-state NMR10.1016/j.polymdegradstab.2016.10.006 ↗
28. Effect of sample dimensions on the stiffness of PA12 lattice materials fabricated using powder bed fusion
29. On the influence of inter-layer time and energy density on selected critical-to-quality properties of PA12 parts produced via laser sintering10.1016/j.polymertesting.2017.05.027 ↗
30. A review of the fatigue behavior of 3D printed polymers
31. Benchmarking of plastic-based additive manufacturing processes
32. Some aspects of nonisothermal crystallization of polymers. I. Relationship between crystallization temperature, crystallinity, and cooling conditions10.1002/app.1972.070160503 ↗
33. Some aspects of nonisothermal crystallization of polymers. II. Consideration of the isokinetic condition10.1002/app.1973.070170404 ↗
34. Isothermal and non-isothermal crystallization kinetics of polyamide 12 used in laser sintering10.1007/s10973-015-5214-8 ↗
35. Non-uniform crystallinity and temperature distribution during adjacent laser-assisted tape winding process of carbon/PA12 pipes10.1007/s00170-020-06215-8 ↗
36. Kinetics of phase change. I general theory10.1063/1.1750380 ↗
37. Characterization and modeling of non-isothermal crystallization of polyamide 12 and co-Polypropylene during the SLS process
38. Analysis of material aging and the influence on the mechanical properties of polyamide 12 in the multi jet fusion process
39. Thermal and oxidative aging effects of Polyamide-11 powder used in multi-jet fusion10.3390/polym15102395 ↗
40. The effect of physical aging and degradation on the Re-Use of polyamide 12 in powder bed fusion10.3390/polym14132682 ↗
41. Effect of thermal-oxidative aging on mechanical, chemical, and thermal properties of recycled polyamide 6610.1002/(SICI)1097-4628(19970822)65:8<1619::AID-APP18>3.0.CO;2-Q ↗
42. Effect of annealing on thermal properties and crystalline structure of polyamides. Nylon 12 (polylaurolactam)10.1007/BF01382456 ↗
43. Comparison between the properties of polyamide 12 and glass bead filled polyamide 12 using the multi jet fusion printing process
44. Effect of water conditioning on the fracture behavior of PA12 composites processed by selective laser sintering10.1016/j.msea.2011.05.045 ↗
45. Effect of water absorption on the properties of selective laser-sintered PA12 specimens10.1007/s40964-024-00826-3 ↗
46. Effect of build direction on tension–tension low cycle fatigue behavior of polyamide 12 parts printed by multi jet fusion10.1016/j.ijfatigue.2023.107514 ↗
47. Effect of the build orientation on the mechanical performance of polymeric parts produced by multi jet fusion and selective laser sintering10.1016/j.jmapro.2021.03.018 ↗
48. Study on geometry, dimensional accuracy and structure of parts produced by multi jet fusion10.3390/ma14164510 ↗
49. Rapid fatigue life evaluation over time of PA12 obtained by multijet fusion printing process