Next Article in Journal
The Effect of Nanostructured Functional Ceramics Additives on the Properties of Welding Electrodes
Next Article in Special Issue
Design of a Cost-Effective and Statistically Validated Test Specification with Selected Machine Elements to Evaluate the Influence of the Manufacturing Process with a Focus on Additive Manufacturing
Previous Article in Journal
Severe Plastic Deformation of Mg–Zn–Zr–Ce Alloys: Advancing Corrosion Resistance and Mechanical Strength for Medical Applications
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Metals
Volume 13
Issue 11
10.3390/met13111848
metals-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Correlation of Different Cemented Carbide Starting Powders with the Resulting Properties of Components Manufactured via Binder Jetting

by
Christian Berger
*,
Johannes Pötschke
,
Uwe Scheithauer
and
Alexander Michaelis
Fraunhofer IKTS, Fraunhofer Institute for Ceramic Technologies and Systems, 01277 Dresden, Germany
*
Author to whom correspondence should be addressed.
Metals 2023, 13(11), 1848; https://doi.org/10.3390/met13111848
Submission received: 30 September 2023 / Revised: 23 October 2023 / Accepted: 27 October 2023 / Published: 4 November 2023
(This article belongs to the Special Issue Benchmarking and Qualification of Additive Manufactured Metallic Components)
Browse Figures
Versions Notes

Abstract

:
For several years, researchers have been exploring the use of the binder jetting powder-based additive manufacturing process to produce WC-Co hardmetals. Compared to other additive manufacturing processes, binder jetting has the potential for high-volume production. However, due to the powder-based approach, the resulting green bodies typically have low green density, limiting the achievable hardness and requiring higher Co content. Choosing the appropriate starting powder and post-processing can extend previous limitations and allow the selection of a suitable powder based on the application. This investigation focuses on exploring and evaluating the correlation between varying morphologies of WC-Co starting powders, their processability using the BJT method, and the resultant mechanical properties of sintered components.

1. Introduction

Hardmetals are composed of a ductile metallic phase and a hard ceramic phase. The main components are tungsten carbide (WC) as a ceramic phase and cobalt (Co) as a metal phase. Cermets also consist of these phases, with TiC or TiCN often used as the ceramic component. The distinctive blend of these phase elements produces different properties, allowing for a diverse range of applications. One of the most significant applications for hardmetals, apart from protecting against wear, is in shaping, where high-strength materials are necessary. The production occurs through traditional powder metallurgy methods. Usually, WC-Co powder is pressed or extruded with shaping agents, but when it comes to complex components, conventional manufacturing processes are limited in their geometric variety. Additive manufacturing can make an important contribution to overcoming these limitations.
The development of hardmetal components through additive manufacturing has been extensively investigated for several years. Various additive manufacturing techniques have been researched, including the classic powder-bed fusion (PBF) processes [1,2,3,4,5,6,7,8], filament-based methods (FFF, MEX) [9,10,11,12,13], suspension-based methods (VPP, MMJ) [14,15,16], and the promising powder-bed-based binder jetting (hereafter referred to as BJT according to ISO/ASTM 52900 [17]). As stated in many publications in the field of powder-bed-based additive manufacturing processes, the properties of the powder used are crucial for success. One of the most important properties is the Co content. Effective placement of the powder is essential due to the inherently loose nature of powders. The powder bed provides support and enables the production of complex geometries. The large-scale application of powders ensures rapid build-up rates of multiple components in the powder bed, so powder properties are critical to achieving defect-free arrangements. This makes the powder-bed-based process highly efficient.
Binder jetting can therefore represent a significant improvement in conventional manufacturing as an additive manufacturing process [18,19]. Furthermore, the powder-based system is distinguished by its low green density compared to conventional pressing or extrusion while also ensuring high productivity. Previously, hardmetals with medium and coarse WC grain size, often exhibiting abnormal WC grain growth, and with a cobalt content of 12 wt.% or above have been studied [20,21,22,23,24,25,26,27,28,29,30]. Investigations on starting materials with smaller WC grain sizes were also carried out with older binder jetting printers [31]. This publication evaluates different starting materials to investigate the potential of producing fully dense parts with complex shapes. Detailed analysis of the microstructure after sintering at various temperatures is provided, including the properties of the powder and green components. Since for WC-Ni granules, a significant higher sintering temperature is necessary for full densification, the comparisons are separated for the WC-Co materials and the studied WC-Ni grade.

2. Materials and Methods

For the experimental part, four different commercially available hardmetal granulates were used. Printed structures were debound and sintered. Samples were characterized along all stages of the process line. Three of the four hardmetals are WC-Co compositions with 12 wt.% Co with different grain sizes and morphologies. The fourth has a WC-Ni composition with 11 wt.%. Ni. Table 1 shows the different starting materials including the supplier and intended use.
To better understand the relations between green part properties and microstructure development during the printing and sintering stages, it is crucial to analyse the morphology of the materials. It is evident that the powders vary not just based on WC grain size but also granule size. Scanning electron micrographs were captured using a Field Emission Secondary Electron Microscope (FESEM) LEO 982 from Carl Zeiss SMT AG (Oberkochen, Germany) for this purpose. The powder cross-sections were used to inspect both the surface and internal structure of the granules. Additionally, apparent density and tap density were measured. The apparent density was determined according to ISO 3923 [32] and tap density was determined according to ISO 3953 [33]. Furthermore, the particle size distribution below 0.1 disperser pressure was measured with a MASTERSIZER 2000 from Malvern Instruments.
An ExOne Innovent+ (today called DesktopMetal InnoventX) was employed for the printing process. The printing fluid saturation of the water-based organic binder was adjusted according to the measured apparent density. The saturation was 70% for the dense granules and between 57% and 62% for the open-pored granules. The assessment of the printing process involves analyzing the printed cubes (10 mm × 10 mm × 10 mm) and different test structures with various features. These features comprise cylindrical discharges of different thickness, as well as gaps ranging from 200 µm to 3 mm in width and channels with varying diameters from 1 mm to 5 mm. Test structures are shown in Figure 1.
In addition to testing the structural integrity of various features, the green density of the printed cubes is also measured based on their geometric dimensions. Furthermore, the compressive strength of cubes is measured using an Instron machine, which runs at a speed of 1 mm/min with a load cell of 1 kN.
Green bodies were debound in a hydrogen atmosphere up to a maximum of 400 °C with a holding time of 1 h and sintered at temperatures ranging from 1350 °C to 1450 °C in 50 K steps under vacuum with defined argon atmosphere of 100 mbar and a holding time of 30 min. An additional SinterHIP step under 100 bar argon pressure and 45 min holding time finally densifies the samples. The sintered specimens underwent characterisation in relation to their density in accordance with ISO 3369 [34], shrinkage (measured green part to sintered part), magnetic properties (magnetic saturation polarization mS and coercive force Hc), porosity using ISO 4499-4 [35], WC grain size distribution using linear analysis based on ISO 4499-2 [36] and their microstructural properties by employing a light microscope and FESEM analysis of polished cross-sections.

3. Results and Discussion

3.1. Characterisation of Starting Materials

The subsequent section presents a comparison of the characterisation results of the respective starting materials. The bulk density, tap density, and porosity are critical factors that influence the compaction process during sintering. The structural and morphological analyses of the starting materials are shown in Figure 2. Details on density and compression indexes are presented in Table 2.
Figure 2 illustrates that WC703 is comprised of a blend of fully compacted and partially porous granules (most noticeable in the cross-sections), with the fully compacted granules displaying a relatively even surface but an extremely uneven distribution of WC grain sizes with grains of 10 µm or more. The granules are round-shaped, due to plasma atomization techniques used during their production. WOKA3110FC and Amperit519.059 appear to be spray-granulated and pre-sintered granules with heightened porosity, resulting in lower green density attributed to increased pore volume.
Material WC703 exhibits higher apparent and tap density compared to WOKA3110FC and Amperit519.059 or Amperit547.059 powders. In addition to the density of the absolute value, the relative density is given in %TD (theoretical density). Furthermore, the ratio between apparent and tap density is one of the lowest, indicating a greater potential for densification during the binder jetting process. The compressibility index is similar to the Hausner factor. It indicates the percentage change (compaction behavior) between apparent density and tapped density when force is applied. It is evident that the respective base materials can compress when exposed to force, such as during the squeegee or recoating stage in the BJT process. To confirm the comparability of the powders, in addition to the results shown so far, the particle/granule size distribution was evaluated and is shown below in Figure 3.
The size distribution shows that the powders are in the same range, ±5 µm of d10 and d50 in µm. Only powders WOKA3110FC and WC703 have a higher proportion of larger granules > 25 µm. It can also be seen that the powders WOKA3110FC and WC703 have a very similar distribution. When comparing the two powders in terms of apparent and tap density, the effect of the porosity of the granules becomes obvious. WOKA3110FC with the high intragranular porosity has lower apparent and tap density values compared to the WC703 powder (see Table 2).

3.2. Shaping of WC-Co Components

The materials were processed utilising an ExOne Innovent+ machine with adjusting the layer thickness to 50 µm. By setting the saturation due to the varying bulk densities, components were successfully produced with all powders available. In the following section, the properties of the green structures are shown (Figure 4) and determined.
Figure 4 demonstrates disparities among the prints with WC-Co. The cube constructed from WC703 showcases the greatest precision in contour, among all printed materials. The test structures show the realisation of almost all features, from slits to bends, demonstrating a remarkable level of geometric autonomy for BJTs with this particular grade of powder. The 200 µm wide slits could not be completely removed from the unused powder. However, complete removal was achieved at 500 µm, which is impressive. In addition, almost all of the smallest 1 mm diameter pins could be printed. The loss of the pin with the powder Amperit519.059 is due to improper handling of the component. The next largest pins with a diameter of 2 mm remained stable despite improper handling. Green bodies made from Amperit519.059 and WOKA3110FC granules indicate slight erosion along their edges, which is presumably caused by lower green strength. The strength measurements of cubes, with a 10 mm edge length and composed of WC703 granules, demonstrated the highest value of 4.3 ± 0.2 MPa. Conversely, cubes formed from Amperit519.059 and WOKA3110FC displayed significantly lower values of 0.7 ± 0.2 MPa and 0.8 ± 0.1 MPa, respectively. It is presumed that distinct morphology and porosity within the granules are responsible for this outcome (refer to Figure 2). As the organic binder infiltrates the granules, effective bonding between them is prevented. This decreases the bond strength and lowers the green strength of printed samples. Nevertheless, handling samples with 0.8 MPa of green strength is still possible. The increased porosity of the granules is also reflected in the green density of the printed components. The powder with the highest green density (44.5%TD) was obtained for WC703, with WOKA3110FC and Amperit519.059 achieving similar densities of 32.4%TD. It can be observed that all these values fall below the powder apparent density (see Table 2), indicating the expected effect of compaction (as described in Table 2) did not occur during the BJT-process under these specified conditions.

3.3. Debinding and Sintering

The impact of sintering has been assessed for three distinct temperatures: 1450 °C, 1400 °C, and 1350 °C. As a result of variations in the grain size distributions and morphology of starting materials, diverse microstructures and properties (Table 3) emerged during the sintering process.
The components produced from WC703 exhibit the smallest coercive force, resulting from the higher grain size of the WC in the granulate. The lower WC grain size in Amperit519.059 results in printed and sintered parts with a much greater coercive force of 9.7 kA/m suggesting a higher hardness than WC703. All samples have a density exceeding 98.5%TD. However, the measurement of density using the Archimedes principle is highly subjective due to the roughness of the surfaces of BJT-printed parts. Therefore, more precise statements can be made from the microstructure images, as depicted in Figure 5. Concerning shrinkage, WC703 parts with the highest green density of 44.5%TD exhibit the approximately 21% linear shrinkage values that are the lowest. Comparatively, green parts with a lower green density of around 32%TD have about 28% linear shrinkage. Additionally, the shrinkage for all test parts showed an anisotropic behavior, which is particularly significant in a higher one in Z-direction.
As indicated by the various coercive forces, Figure 5 demonstrates contrasting microstructures of the sintered parts. Notably, WC703 exhibits a significantly larger grain size for WC, which corresponds to the coarse starting powder grain size. Similarly, fine-grained starting materials result in a finer grain size post-sintering, while WOKA3110FC displays partial abnormal grain growth. Potential causes for the observed phenomena include unwanted constituents from the manufacturing process or the notably elevated carbon content of the samples, as inferred from the high magnetic saturation data presented in Table 3. The absence of free carbon or eta phase in any of the microstructures suggests that the samples fall within the desired two-phase region of WC and Co. Among them, the microstructure of Amperit519.059 exhibits no atypical grain growth and represents the optimal material in terms of the least grain size and uniformity.
Reducing the sintering temperature by 50 K to 1400 °C resulted in the unwanted formation of free carbon, which is apparent in microstructures shown in Figure 6. Black, clumped precipitates signify the presence of free carbon.
By modifying the debinding and sintering procedures, the formation of unbound carbon could be avoided, and a microstructure without the undesirable free carbon or eta phase is created (Figure 7). This was realized by raising the debinding temperature under a reducing environment (H2) by 200 K and extending the holding time of the debindering step by 1 h.
Figure 7 demonstrates that there is little difference in sintering between 1450 °C and 1400 °C (compared to Figure 5). At a further reduced sintering temperature of 1350 °C, and with modified debinding and sintering regimes, the parts were almost entirely densified as well. However, larger pores were still present at the edges of the WOKA3110FC sample. This suggests that the minimum sintering temperature is between 1350 °C and 1400 °C (Figure 8). Further lowering the sintering temperature would most likely result in a rise in the defect concentration, manifesting as additional pores.
The microstructures shows that the samples WOKA3110FC and Amperit519.059 had again a smaller WC grain size. However, no reduction in abnormal grain growth was observed in WOKA3110FC, nor a decrease in WC703 grain size.
The light microscopy images provided a clear indication of the material’s porosity and basic information. Further insight into the distribution of Co and the size of WC can be seen in Figure 9, where FESEM images captured in angle selective backscatter mode are presented.
FESEM images of the microstructures show that the resulting grain size varies considerably. WC 703 displays a notably coarser WC structure, attributed in part to the similarly coarse WC grains present in the initial material. The measurement of WC grain sizes showed that the coarsest structure was obtained with a d10 of 0.7 µm, a d50 of 2.8 µm, a d90 of 6.7 µm, and a d99 of 11.6 µm. In contrast, as previously stated, Amperit519.059 maintains a fine structure throughout. This is also shown by the WV grain size distribution of a d10 of 0.2 µm, a d50 of 0.6 µm, a d90 of 1.4 µm, and a d99 of 2.2 µm. This is much narrower and shifted to smaller values compared to WC703. The WOKA3110FC exhibits a tendency towards abnormal grain growth. The WC grain size distribution was measured from two areas. Firstly, from the fine microstructure, where the values with d10 of 0.2 µm, a d50 of 0.6 µm, a d90 of 1.3 µm, and a d99 of 2.3 µm are very similar to those of Amperit519.059, and secondly from the giant grain growth, which has an effect especially in the d90 of 1.5 µm and d99 of 3.8 µm. Despite the Amperit519.059 powder’s low green density, the microstructure exhibits fine features and predominantly homogeneous Co distribution at a sintering temperature of 1350 °C. The physical properties of both the WOKA3110FC and Amperit519.059 powders are also comparable. Refer to Table 4 for a comparison of physical properties after sintering at 1350 °C and 1400 °C.
Table 4 indicates a slight decrease in density from Table 3, which is also reflected in the microstructural images presented in Figure 7. The increase in coercive force suggests for all samples a smaller WC grain size.
In addition to their high hardness, the parts manufactured from Amperit519.059 display lowest porosity with ISO values of approximately A04B00C00. The microstructural properties in this study align with those of traditionally manufactured hardmetal components that share the same Co content and WC grain size.

3.4. WC-Ni as an Alternate Material System

The initial powder characterisations of Amperit547.059 show that the structure of WC-Ni is similar to that of the WC-Co spray powders. As anticipated, stable green bodies with a green density of 33%TD can also be created with a layer thickness of 50 µm using WC-Ni, as illustrated in Figure 10.
The level of detail is comparable to that of WC-Co deposits. For sintering, on the other hand, the studied WC-Ni powder Amperit547.059 requires a different sintering regime. Even at a sintering temperature of 1500 °C, the body could not be fully compacted. This required 100 K more, as can be seen in Figure 11.
Sintering at 1500 °C resulted in a still porous structure (Figure 11). The different shades of grey at the edges of the square areas are due to stitching during image acquisition and therefore do not represent a microstructure. However, an assessment of the porosity is possible. Owing to the eutectic point of the liquid phase system at elevated temperatures and the higher wetting angle of WC-Ni (eutectic point = 1340 °C) in comparison to WC-Co (eutectic point = 1280 °C), 1600 °C sintering temperatures were deemed mandatory for full densification according to the microstructural images. The evaluated density of 14.2 g/cm3/98.4%TD and the porosity of A06B00C00 does not correlate with the microstructural images, which may indicate a microstructural transformation or the influence of the high roughness of the measured samples and will be investigated in further work. The linear shrinkage with 28.6%, 29.5%, and 31.4% are comparable to the porous WC-Co granules with similar granule size distribution.
Furthermore, the micrographs indicated that the microstructure becomes coarser at higher temperatures in comparison to WC-Co (Figure 12).
This is also shown by the WC grain size distribution of d10 of 1.0 µm, a d50 of 2.8 µm, a d90 of 6.7 µm, and a d99 of 12.5 µm, which represents a coarsening of the grain size by a factor of about 5 compared to WC-Co. The coarser structure results in a hardness of 964 ± 16 HV10. In comparison between the composites WC-Ni and WC-Co with comparable starting powders, the WC-Co is to be preferred due to the finer microstructures and lower sintering temperatures. However, it could also be shown that a WC-Ni, which should offer a higher corrosion resistance as compared to WC-Co, can be produced via binder jetting to parts with dense microstructures.

4. Conclusions

In addition to WC-Co powders available on the market for additive manufacturing (such as grade WC703 from GTP), it has been found that other commercial starting materials are appropriate for use in binder jetting as well. Among these starting materials are Amperit519.059 (WC-Co), Amperit517.059 (WC-Ni) from Höganäs, and WOKA3110FC (WC-Co) from Oerlikon, which were initially developed for thermal spray purposes. These powders are not optimised for high green densities yet have a homogeneous fine grain size in the feedstock, unlike Global Tungsten Powder’s WC703. All the powders described can produce geometrical complex objects. WC703 generates the highest green part strength of 4.7 MPa, while the other two indicate strength values of approximately just 1 MPa. During the sintering process, parts can achieve almost complete densification at temperatures as low as 1350 °C, which falls within or below the range of temperatures used for sintering conventionally produced green parts. However, parts produced from powder WC703 have lower hardness after sintering, due to their high initial WC grain size. Out of the three WC-12Co powders investigated, only Amperit519.059 shows a suitable microstructure with a homogeneous phase distribution in the two-phase WC and Co area after sintering. Moreover, the components maintain a small WC grain size and exhibit elevated hardness exceeding 1300 HV10. Like in traditional hardmetal production, the starting material’s WC grain size significantly affects the microstructure following sintering. Given the high 12 wt.% Co fraction and the consequent hardness, the hardmetals created in this study are primarily fit for use in shaping or wear protection. With regard to the presumably higher corrosion protection [37], it was also shown that WC-Ni containing hardmetals can be completely compacted via BJT as well. Subsequent investigations will concentrate on powders possessing lesser Co contents and smaller WC grain sizes.

Author Contributions

Conceptualization, C.B., J.P., U.S. and A.M.; methodology, C.B.; software, C.B.; validation, C.B. and J.P.; formal analysis, C.B.; investigation, C.B., U.S. and J.P.; data curation, C.B.; writing—original draft preparation, C.B.; writing—review and editing, C.B., J.P., U.S. and A.M.; visualisation, C.B.; supervision, J.P. and A.M.; project administration, J.P.; funding acquisition, J.P. All authors have read and agreed to the published version of the manuscript.

Funding

This research was partially funded by ExOne GmbH as part of DesktopMetal Inc.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author, C.B., upon reasonable request.

Acknowledgments

We would like to thank ExOne GmbH as part of DesktopMetal Inc. for providing the starting material from GTP and the technical support of the used Innovent+ printer (today called DesktopMetal InnoventX). Furthermore, the authors would like to thank Daniel Reichenbach and Manfred Fries for measuring the powder properties and Thomas Mylius for carrying out the printing jobs.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Schwanekamp, T. Pulverbettbasiertes Laserstrahlschmelzen von Hartmetallen zur Additiven Herstellung von Zerspanwerkzeugen. Ph.D. Thesis, Ruhr-Universität Bochum, Universitätsbibliothek, Bochum, Germany, 2021. [Google Scholar]
  2. Schwanekamp, T.; Marginean, G.; Reuber, M. Laser beam melting of Cr3C2-NiCr. Int. J. Refract. Met. Hard Mater. 2019, 85, 105069. [Google Scholar] [CrossRef]
  3. Fries, S.; Vogelpoth, A.; Kaletsch, A.; Broeckmann, C. Laser-Based Additive Manufacturing of WC–Co with High-Temperature Powder Bed Preheating. Steel Res. Int. 2020, 91, 1900511. [Google Scholar] [CrossRef]
  4. Fries, S.; Vogelpoth, A.; Kaletsch, A.; Broeckmann, C. Influence of post heat treatment on microstructure and fracture strength of cemented carbides manufactured using laser-based additive manufacturing. Int. J. Refract. Met. Hard Mater. 2023, 111, 106085. [Google Scholar] [CrossRef]
  5. Schwanekamp, T.; Marginean, G.; Reuber, M.; Ostendorf, A. Impact of cobalt content and grain growth inhibitors in laser-based powder bed fusion of WC-Co. Int. J. Refract. Met. Hard Mater. 2022, 105, 105814. [Google Scholar] [CrossRef]
  6. Xing, M.; Wang, H.; Zhao, Z.; Lu, H.; Liu, C.; Lin, L. Additive manufacturing of cemented carbides inserts with high mechanical performance. Mater. Sci. Eng. A 2022, 861, 144350. [Google Scholar] [CrossRef]
  7. Zhang, L.; Hu, C.; Yang, Y.; Misra, R.; Kondoh, K.; Lu, Y. Laser powder bed fusion of cemented carbides by developing a new type of Co coated WC composite powder. Addit. Manuf. 2022, 55, 102820. [Google Scholar] [CrossRef]
  8. Ibe, H.; Kato, Y.; Yamada, J.; Kato, M.; Suzuki, A.; Takata, N. Controlling WC/Co two-phase microstructure of cemented carbides additive-manufactured by laser powder bed fusion: Effect of powder composition and post heat-treatment. Mater. Des. 2021, 210, 110034. [Google Scholar] [CrossRef]
  9. Lengauer, W.; Duretek, I.; Schwarz, V.; Kukla, C.; Kitzmantel, M.; Neubauer, E.; Lieberwirth, C.; Morrison, V. Preparation and properties of extrusion-based 3D-printed hardmetal and cermet parts. In Proceedings of the Euro PM2018 Congress & Exhibition Euro PM2018 Proceedings, Bilbao Exhibition Centre (BEC), Bilbao, Spain, 14–18 October 2018; European Powder Metallurgy Association (EPMA): Shrewsbury, UK, 2018. [Google Scholar]
  10. Berger, C.; Abel, J.; Pötschke, J.; Moritz, T. Properties of Additive Manufactured Hardmetal Components Produced by Fused Filament Fabrication (FFF). In Proceedings of the Euro PM2018 Congress & Exhibition Euro PM2018 Proceedings, Bilbao Exhibition Centre (BEC), Bilbao, Spain, 14–18 October 2018; European Powder Metallurgy Association (EPMA): Shrewsbury, UK, 2018. [Google Scholar]
  11. Lengauer, W.; Duretek, I.; Fürst, M.; Schwarz, V.; Gonzalez-Gutierrez, J.; Schuschnigg, S.; Kukla, C.; Kitzmantel, M.; Neubauer, E.; Lieberwirth, C. Fabrication and properties of extrusion-based 3D-printed hardmetal and cermet components. Int. J. Refract. Met. Hard Mater. 2019, 82, 141–149. [Google Scholar] [CrossRef]
  12. Zhao, Z.; Liu, R.; Chen, J.; Xiong, X. Additive manufacturing of cemented carbide using analogous powder injection molding feedstock. Int. J. Refract. Met. Hard Mater. 2023, 111, 106095. [Google Scholar] [CrossRef]
  13. Lee, S.W.; Kim, Y.W.; Jang, K.M.; Lee, J.W.; Park, M.-S.; Koo, H.Y.; Ha, G.-H.; Kang, Y.C. Phase control of WC–Co hardmetal using additive manufacturing technologies. Powder Metall. 2021, 65, 13–21. [Google Scholar] [CrossRef]
  14. Rieger, T.; Schubert, T.; Schurr, J.; Butschle, M.; Schwenkel, M.; Bernthaler, T. Slurry development for lithography-based additive manufacturing of cemented carbide components. Powder Technol. 2021, 383, 498–508. [Google Scholar] [CrossRef]
  15. Rieger, T.; Schubert, T.; Schurr, J.; Kolb, D.; Riegel, H.; Bernthaler, T.; Schneider, G. Manufacturing (AM). In Proceedings of the Euro PM2019 Congress & Exhibition Euro PM2019 Proceedings, Maastricht Exhibition & Congress Centre (MECC), Maastricht, The Netherlands, 13–16 October 2019; European Powder Metallurgy Association (EPMA): Shrewsbury, UK, 2019; pp. 1–6. [Google Scholar]
  16. Pötschke, J.; Weingarten, S.; Scheithauer, U.; Mayer, M.; Moritz, T. Thermoplastic 3D Printing of Hardmetals. In Proceedings of the Euro PM2019 Congress & Exhibition Euro PM2019 Proceedings, Maastricht Exhibition & Congress Centre (MECC), Maastricht, The Netherlands, 13–16 October 2019; European Powder Metallurgy Association (EPMA): Shrewsbury, UK, 2019; pp. 1–6. [Google Scholar]
  17. ASTM 52900:2021; Additive Manufacturing–General Principles–Fundamentals and Vocabulary. Beuth Verlag GmbH: Berlin, Germany, 2022.
  18. Mostafaei, A.; Elliott, A.M.; Barnes, J.E.; Li, F.; Tan, W.; Cramer, C.L.; Nandwana, P.; Chmielus, M. Binder jet 3D printing—Process parameters, materials, properties, modeling, and challenges. Prog. Mater. Sci. 2021, 119, 100707. [Google Scholar]
  19. Dini, F.; Ghaffari, S.A.; Jafar, J.; Hamidreza, R.; Marjan, S. A review of binder jet process parameters; powder, binder, printing and sintering condition. Met. Powder Rep. 2020, 75, 95–100. [Google Scholar] [CrossRef]
  20. Carreño-Morelli, E.; Alveen, P.; Moseley, S.; Rodriguez-Arbaizar, M.; Cardoso, K. A comparative study of cemented carbide parts produced by solvent on granules 3D-printing (SG-3DP) versus press and sinter. Int. J. Refract. Met. Hard Mater. 2021, 97, 105515. [Google Scholar] [CrossRef]
  21. Wolfe, T.; Shah, R.; Prough, K.; Trasorras, J.L. Coarse cemented carbide produced via binder jetting 3D printing. Int. J. Refract. Met. Hard Mater. 2023, 110, 106016. [Google Scholar] [CrossRef]
  22. Lehmann, M.; Kolb, C.G.; Gschloessl, J.; Zaeh, M.F. Using particle-loaded inks to selectively change the material properties in binder-jetted WC–Co parts. J. Mater. Sci. 2023. [Google Scholar] [CrossRef]
  23. Enneti, R.K.; Prough, K.C. Wear properties of sintered WC-12%Co processed via Binder Jet 3D Printing (BJ3DP). Int. J. Refract. Met. Hard Mater. 2019, 78, 228–232. [Google Scholar] [CrossRef]
  24. Carreño-Morelli, E.; Alveen, P.; Moseley, S.; Rodriguez-Arbaizar, M.; Cardoso, K. Three-dimensional printing of hard materials. Int. J. Refract. Met. Hard Mater. 2020, 87, 105–110. [Google Scholar] [CrossRef]
  25. Tang, J.-Y.; Luo, L.-M.; Liu, Z.; Zan, X.; Wu, Y.-C. Shape retention of cemented carbide prepared by Co melt infiltration into un-sintered WC green parts made via BJ3DP. Int. J. Refract. Met. Hard Mater. 2022, 107, 105904. [Google Scholar] [CrossRef]
  26. Yang, Y.; Zhang, C.; Wang, D.; Nie, L.; Wellmann, D.; Tian, Y. Additive manufacturing of WC-Co hardmetals: A review. Int. J. Adv. Manuf. Technol. 2020, 64, 219. [Google Scholar] [CrossRef]
  27. Aramian, A.; Razavi, S.M.J.; Sadeghian, Z.; Berto, F. A review of additive manufacturing of cermets. Addit. Manuf. 2020, 33, 101130. [Google Scholar] [CrossRef]
  28. Padmakumar, M. Additive Manufacturing of Tungsten Carbide Hardmetal Parts by Selective Laser Melting (SLM), Selective Laser Sintering (SLS) and Binder Jet 3D Printing (BJ3DP) Techniques. Lasers Manuf. Mater. Process. 2020, 7, 338–371. [Google Scholar]
  29. Azurmendi, N.; Agote, I.; Lores, A.; Fernandes, C.M.; Figuereido, D. Binder jetting of hardmetals: A comparative study of microstructure and properties of different commercial powders. In Proceedings of the World PM2022 Congress & Exhibition World PM2018 Proceedings, Lyon Convention Centre, Lyon, France, 9–13 October 2022; European Powder Metallurgy Association (EPMA): Chantilly, France, 2022. [Google Scholar]
  30. Mariani, M.; Goncharov, I.; Mariani, D.; De Gaudenzi, G.P.; Popovich, A.; Lecis, N.; Vedani, M. Mechanical and microstructural characterization of WC-Co consolidated by binder jetting additive manufacturing. Int. J. Refract. Met. Hard Mater. 2021, 100, 105639. [Google Scholar] [CrossRef]
  31. Berger, C.; Pötschke, J.; Fries, M.; Moritz, T.; Michaelis, A. Binder-jetting of TiCN-based cermets. Powder Metall. 2022, 65, 382–389. [Google Scholar] [CrossRef]
  32. ISO 3923­1:2018; Metallic Powders–Determination of Apparent Density–Part 1: Funnel Method. Beuth Verlag GmbH: Berlin, Germany, 2018.
  33. ISO 3953:2011; Metallic Powders–Determination of Tap Density. Beuth Verlag GmbH: Berlin, Germany, 2011.
  34. ISO 3369:2006; Impermeable Sintered Metal Materials and Hardmetals–Determination of Density. Beuth Verlag GmbH: Berlin, Germany, 2010.
  35. ISO 4499­4:2016; Hardmetals–Metallographic Determination of Microstructure–Part 4: Characterisation of Porosity, Carbon Defects and Eta­Phase Content. Beuth Verlag GmbH: Berlin, Germany, 2016.
  36. ISO 4499­2:2020; Hardmetals–Metallographic Determination of Microstructure–Part 2: Measurement of WC Grain Size. Beuth Verlag GmbH: Berlin, Germany, 2020.
  37. Rocha, A.F.; Bastos, A.C.; Cardoso, J.P.; Rodrigues, F.; Fernandes, C.M.; Soares, E.; Sacramento, J.; Senos, A.M.R.; Ferreira, M.G.S. Corrosion behaviour of WC hardmetals with nickel-based binders. Corros. Sci. 2019, 147, 384–393. [Google Scholar]
Metals 13 01848 g001
Figure 1. CAD data for the green parts.
Figure 1. CAD data for the green parts.
Metals 13 01848 g001
Metals 13 01848 g002
Figure 2. FESEM images of surface and cross-section of granules WC703 (WC-Co), WOKA3110FC (WC-Co), Amperit519.059 (WC-Co), and Amperit547.059 (WC-Ni).
Figure 2. FESEM images of surface and cross-section of granules WC703 (WC-Co), WOKA3110FC (WC-Co), Amperit519.059 (WC-Co), and Amperit547.059 (WC-Ni).
Metals 13 01848 g002
Metals 13 01848 g003
Figure 3. Granule size distribution of the different starting materials.
Figure 3. Granule size distribution of the different starting materials.
Metals 13 01848 g003
Metals 13 01848 g004
Figure 4. Images of cubes with structural elements and test structures of WC-Co.
Figure 4. Images of cubes with structural elements and test structures of WC-Co.
Metals 13 01848 g004
Metals 13 01848 g005
Figure 5. Microstructure of the samples sintered at 1450 °C with different magnifications.
Figure 5. Microstructure of the samples sintered at 1450 °C with different magnifications.
Metals 13 01848 g005
Metals 13 01848 g006
Figure 6. Microstructures of the samples sintered at 1400 °C with free carbon.
Figure 6. Microstructures of the samples sintered at 1400 °C with free carbon.
Metals 13 01848 g006
Metals 13 01848 g007aMetals 13 01848 g007b
Figure 7. Microstructures of the samples sintered at 1400 °C without free carbon.
Figure 7. Microstructures of the samples sintered at 1400 °C without free carbon.
Metals 13 01848 g007aMetals 13 01848 g007b
Metals 13 01848 g008
Figure 8. Microstructure images (light microscope) of the samples sintered at 1350 °C.
Figure 8. Microstructure images (light microscope) of the samples sintered at 1350 °C.
Metals 13 01848 g008
Metals 13 01848 g009
Figure 9. Microstructure images (FESEM) of the samples sintered at 1350 °C.
Figure 9. Microstructure images (FESEM) of the samples sintered at 1350 °C.
Metals 13 01848 g009
Metals 13 01848 g010
Figure 10. Printed green parts of Amperit547.059 (WC-Ni).
Figure 10. Printed green parts of Amperit547.059 (WC-Ni).
Metals 13 01848 g010
Metals 13 01848 g011
Figure 11. Microstructures of the samples sintered at 1500 °C (left) and 1600 °C (Right) of Amperit547.059 (WC-Ni).
Figure 11. Microstructures of the samples sintered at 1500 °C (left) and 1600 °C (Right) of Amperit547.059 (WC-Ni).
Metals 13 01848 g011
Metals 13 01848 g012
Figure 12. Microstructure images (FESEM) of the sample sintered at 1600 °C (WC-Ni) (left) and sintered at 1350 °C (WC-Co) (right).
Figure 12. Microstructure images (FESEM) of the sample sintered at 1600 °C (WC-Ni) (left) and sintered at 1350 °C (WC-Co) (right).
Metals 13 01848 g012
Table 1. Starting materials for the binder jetting process.
Table 1. Starting materials for the binder jetting process.
CompanyGlobal Tungsten PowdersOerlikon MetcoHöganäsHöganäs
TypeWC703WOKA3110FCAmperit519.059Amperit547.059
MaterialWC-12CoWC-12CoWC-12CoWC-11Ni
WC Grain SizeCoarse
(2.5–6.0 µm)		Fine
(0.8–1.3 µm)		Fine
(0.8–1.3 µm)		Fine
(0.8–1.3 µm)
ApplicationAdditive ManufacturingHigh velocity oxygen fuel spraying (HVOF)High velocity oxygen fuel spraying (HVOF)High velocity
oxygen fuel
spraying (HVOF)
Table 2. Powder properties of the starting materials.
Table 2. Powder properties of the starting materials.
PropertiesWC703WOKA3110FCAmperit519.059Amperit547.059
Apparent density [g/cm3/%TD]6.7/46.35.4/37.95.1/35.84.9/34.2
Tap density [g/cm3/%TD]7.7/53.66.8/47.06.0/41.85.7/39.3
Compressibility index15.624.116.715.0
Granule size ditribution
      d10 [µm}13.513.412.214.3
      d50 [µm]22.722.718.420.9
      d90 [µm]37.037.027.630.1
Table 3. Properties of samples sintered at 1450 °C.
Table 3. Properties of samples sintered at 1450 °C.
PropertiesWC703WOKA3110FCAmperit519.059
Density [g/cm3/%TD]14.2/98.514.2/99.214.3/99.2
Mag. Saturation [µTm3/kg/%TmS]23.9/99.023.7/98.223.6/97.8
Hc [kA/m]3.98.69.7
Lin. shrinkage X/Y/Z [%]20.1/20.8/22.227.2/27.6/29.527.7/28.1/29.4
Porosity (ISO 4499-4)A06B04C00A04B00C00A04B00C00
Table 4. Properties of samples sintered at 1350 °C and 1400 °C.
Table 4. Properties of samples sintered at 1350 °C and 1400 °C.
PropertiesSintering Temperature [°C]WC703WOKA3110FCAmperit519.059
Density [g/cm3/%TD]135014.2/98.714.3/99.414.2/99.0
140014.2/98.814.3/99.414.3/99.5
Mag. Saturation [µTm3/kg/%TmS]135024.0/99.524.0/99.523.9/99.0
140023.5/97.423.5/97.423.4/97.0
Hc [kA/m]13504.19.9 10.3
14004.18.910.0
Hardness [HV10]1400910 ± 101211 ± 81300 ± 14
Lin. Shrinkage X/Y/Z [%]135020.5/21.1/22.826.2/26.5/29.226.8/27.5/29.1
140018.7/19.6/21.627.3/27.5/29.527.0/27.9/28.4
Porosity (ISO 4499-4)1350A06B00C00A08B00C00
(inner structure)		A04B00C00
1400A06B00C00A06B00C00A04B00C00
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Berger, C.; Pötschke, J.; Scheithauer, U.; Michaelis, A. Correlation of Different Cemented Carbide Starting Powders with the Resulting Properties of Components Manufactured via Binder Jetting. Metals 2023, 13, 1848. https://doi.org/10.3390/met13111848

AMA Style

Berger C, Pötschke J, Scheithauer U, Michaelis A. Correlation of Different Cemented Carbide Starting Powders with the Resulting Properties of Components Manufactured via Binder Jetting. Metals. 2023; 13(11):1848. https://doi.org/10.3390/met13111848

Chicago/Turabian Style

Berger, Christian, Johannes Pötschke, Uwe Scheithauer, and Alexander Michaelis. 2023. "Correlation of Different Cemented Carbide Starting Powders with the Resulting Properties of Components Manufactured via Binder Jetting" Metals 13, no. 11: 1848. https://doi.org/10.3390/met13111848

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop