Productivity enhancement of laser powder bed fusion using compensated shelled geometries and hot isostatic pressing

Plessis, Anton du; Yelamanchi, Bharat; Fischer, Christian B.; Miller, James A.; Beamer, C. Walter; Rogers, Kirk; Cortes, Pedro; Els, Johan; MacDonald, Eric

doi:10.1016/j.aime.2021.100031

Cited by 16 publications

(8 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The same conclusions can be rewritten for AlSi10Mg as-built samples [ 14 , 104 ]. In this scenario, the hot isostatic pressing (HIP) HT can be used not only to densify the material but also to reduce the residual stress [ 105 , 106 ]. At the same time, if the fatigue resistance is increased due to the pore’s reduction, the tensile properties of Ti6Al4V samples decrease, as can be observed in Figure 7 [ 107 , 108 , 109 , 110 , 111 ].…”

Section: Laser-powder Bed Fusion (L-pbf) Processmentioning

confidence: 99%

Additive Manufacturing of AlSi10Mg and Ti6Al4V Lightweight Alloys via Laser Powder Bed Fusion: A Review of Heat Treatments Effects

Ghio

Cerri

2022

Materials

View full text Add to dashboard Cite

Laser powder bed fusion (L-PBF) is an additive manufacturing technology that is gaining increasing interest in aerospace, automotive and biomedical applications due to the possibility of processing lightweight alloys such as AlSi10Mg and Ti6Al4V. Both these alloys have microstructures and mechanical properties that are strictly related to the type of heat treatment applied after the L-PBF process. The present review aimed to summarize the state of the art in terms of the microstructural morphology and consequent mechanical performance of these materials after different heat treatments. While optimization of the post-process heat treatment is key to obtaining excellent mechanical properties, the first requirement is to manufacture high quality and fully dense samples. Therefore, effects induced by the L-PBF process parameters and build platform temperatures were also summarized. In addition, effects induced by stress relief, annealing, solution, artificial and direct aging, hot isostatic pressing, and mixed heat treatments were reviewed for AlSi10Mg and Ti6AlV samples, highlighting variations in microstructure and corrosion resistance and consequent fracture mechanisms.

show abstract

Section: Laser-powder Bed Fusion (L-pbf) Processmentioning

confidence: 99%

Additive Manufacturing of AlSi10Mg and Ti6Al4V Lightweight Alloys via Laser Powder Bed Fusion: A Review of Heat Treatments Effects

Ghio

Cerri

2022

Materials

View full text Add to dashboard Cite

show abstract

“…External dimensions were also assessed after a post processing method known as hot isostatic pressing which involves high temperature and pressure to consolidate internal voids and relieve internal stresses. It is unlikely that the consolidation of internal voids will have a significant effect on external dimensions, but relieving internal stresses may affect dimensional stability [ 21 ]. It was found that post processing these samples via hot isostatic press appeared to create a statistically significant difference in most part dimensions with the largest difference seen in the Laser 1 length measurements with a difference of 150 μm.…”

Section: Discussionmentioning

confidence: 99%

Dimensional variability characterization of additively manufactured lattice coupons

et al. 2022

View full text Add to dashboard Cite

Background Additive manufacturing (AM), commonly called 3D Printing (3DP), for medical devices is growing in popularity due to the technology’s ability to create complex geometries and patient-matched products. However, due to the process variabilities which can exist between 3DP systems, manufacturer workflows, and digital conversions, there may be variabilities among 3DP parts or between design files and final manufactured products. The overall goal of this project is to determine the dimensional variability of commercially obtained 3DP titanium lattice-containing test coupons and compare it to the original design files. Methods This manuscript outlines the procedure used to measure dimensional variability of 3D Printed lattice coupons and analyze the differences in external dimensions and pore area when using laser and electron beam fabricated samples. The key dimensions measured were the bulk length, width, and depth using calipers. Strut thickness and pore area were assessed for the lattice components using optical imaging and µCT. Results Results show a difference in dimensional measurement between printed parts and the computer-designed files for all groups analyzed including the internal lattice dimensions. Measurements of laser manufactured coupons varied from the nominal by less than 0.2 mm and results show averages greater than the nominal value for length, width, and depth dimensions. Measurements of Electron Beam Melting coupons varied between 0.4 mm-0.7 mm from the nominal value and showed average lengths below the nominal dimension while the width and depths were greater than the nominal values. The length dimensions of Laser Powder Bed Fusion samples appeared to be impacted by hot isostatic press more than the width and depth dimension. When lattice relative density was varied, there appeared to be little impact on the external dimensional variability for the as-printed state. Conclusions Based on these results, we can conclude that there are relevant variations between designed files and printed parts. However, we cannot currently state if these results are clinically relevant and further testing needs to be conducted to apply these results to real-world situations.

show abstract

“…Laser powder bed fusion of Ti6Al4V (ELI) was used to manufacture samples, using an EOS M290 machine located at Executive Engineering Pty Ltd, South Africa. Hot isostatic pressing was performed at Quintus Technologies Inc (Sweden) and CT scans performed at Stellenbosch University as reported previously in [10][11][12]. In this work, synchrotron tomography was additionally performed at the ID19 beamline of the ESRF.…”

Section: Methodsmentioning

confidence: 99%

“…However, pores connected to the surface caused imperfect pore closure. This concept was utilized in subsequent work to increase the LPBF-HIP combined process productivity by manufacturing only shells and thereby saving significant laser processing time [11,12]. Despite the success of this approach, pore closure is not expected to be fully successful, as the argon gas is not soluble in the titanium matrix, hence "squeezed pores" still exist in this material, which is of interest here.…”

Section: Introductionmentioning

confidence: 99%

X-ray tomography study of “squeezed pores” in additively manufactured titanium alloy subjected to hot isostatic pressing

Plessis¹,

Desrosiers²,

Majkut³

et al. 2023

eJNDT

View full text Add to dashboard Cite

Metal additive manufacturing is a fast-growing manufacturing technology for producing components with complex geometries and in short lead times. The widely used Ti6Al4V alloy has particularly good strength to weight ratio while having properties suitable for aerospace and medical industries. The additive manufacturing processes all involve layer by layer processing, often leading to small porosities in the final produced parts. These can lead to reduced mechanical properties, especially fatigue performance is negatively influenced. Hot isostatic pressing (HIP) has in recent years become an important post-process to eliminate these pores, improve the microstructure and enhance the fatigue performance of such parts. In this work, the pore closure and shrinkage due to HIP of Ti6Al4V is studied using high resolution laboratory and synchrotron tomography. This reveals “squeezed pores” which are visible only using high resolution synchrotron tomography and not in a typical laboratory resolution system. This paper reports on the imaging of such pores, handling of this data and discusses future work involving intentionally created defects of different morphologies and efforts to study their shrinkage behavior due to HIP processing.

show abstract

Productivity enhancement of laser powder bed fusion using compensated shelled geometries and hot isostatic pressing

Cited by 16 publications

References 38 publications

Additive Manufacturing of AlSi10Mg and Ti6Al4V Lightweight Alloys via Laser Powder Bed Fusion: A Review of Heat Treatments Effects

Additive Manufacturing of AlSi10Mg and Ti6Al4V Lightweight Alloys via Laser Powder Bed Fusion: A Review of Heat Treatments Effects

Dimensional variability characterization of additively manufactured lattice coupons

X-ray tomography study of “squeezed pores” in additively manufactured titanium alloy subjected to hot isostatic pressing

Contact Info

Product

Resources

About