Microstructures and Mechanical Properties of Co-Cr Dental Alloys Fabricated by Three CAD/CAM-Based Processing Techniques
"> Figure 1
<p>XRD patterns of the Co-Cr alloys tested. The black arrow in the ML group indicates a shift of the (111) plane. The SLM group showed only the presence of the Co-based <span class="html-italic">γ</span> (fcc) phase. The carbide (M<sub>23</sub>C<sub>6</sub>) formation was identified only in the ML/PS group.</p> "> Figure 2
<p>Optical microscopy images of the Co-Cr alloys tested. (<b>a</b>) CS; (<b>b</b>) ML; (<b>c</b>) SLM; and (<b>d</b>) ML/PS (200×, scale bar = 100 μm). The red rounded squares in the small box in C indicate laser scan traces (small box in C: 100×, scale bar = 100 μm).</p> "> Figure 3
<p>BSE images of the Co-Cr alloys tested. (<b>a</b>) CS; (<b>b</b>) ML; (<b>c</b>) SLM; and (<b>d</b>) ML/PS (500×, scale bar = 30 μm). The secondary phases were observed in the CS and ML specimens, but such phases were absent in the SLM specimen.</p> "> Figure 4
<p>BSE and corresponding EDS mapping images for each group. (<b>a</b>) CS; (<b>b</b>) ML; (<b>c</b>) SLM; and (<b>d</b>) ML/PS (500×, scale bar = 50 μm).</p> "> Figure 5
<p>BSE images of the Co-Cr alloys for EDS point analysis. (<b>a</b>) CS; (<b>b</b>) ML; (<b>c</b>) SLM; and (<b>d</b>) ML/PS (10,000×, scale bar = 1 μm). In each figure, the numbers indicate the points subjected to the EDS analysis.</p> "> Figure 6
<p>BSE image (band contrast map) for each group and corresponding phase and inverse pole figure (IPF) maps. (<b>a</b>) CS; (<b>b</b>) ML; (<b>c</b>) SLM; and (<b>d</b>) ML/PS (500×, scale bar = 50 μm).</p> "> Figure 7
<p>Comparison of mechanical properties of the four Co-Cr alloys tested (<span class="html-italic">n</span> = 6). For each figure, means with different letters indicate statistical differences between groups (<span class="html-italic">p</span> < 0.05). The green and blue horizontal lines indicate the type 4 and 5 criteria (minimum value), respectively, in ISO 22674. The type 4 and 5 criteria are the same for percent elongation (black horizontal line).</p> "> Figure 8
<p>SEM images of the fractured surfaces after tensile test. (<b>a</b>) CS; (<b>b</b>) ML; (<b>c</b>) SLM; and (<b>d</b>) ML/PS (500×, scale bar = 30 μm).</p> ">
Abstract
:1. Introduction
2. Results
2.1. X-ray Diffraction Analysis
2.2. Microscopic Characterization
2.3. Mechanical Properties and Fracture Surfaces
3. Discussion
4. Materials and Methods
4.1. Specimen Preparation
4.2. XRD Analysis
4.3. Microscopic Characterization
4.4. Mechanical Properties
4.5. Statistical Analysis
5. Conclusions
- Co-Cr dental alloys prepared via three new CAD/CAM-based processing techniques (milling (ML), selective laser melting (SLM), and milling/post-sintering (ML/PS)) showed differences in microstructure and related mechanical properties not only from the traditional casting technique, but also among each other.
- Overall, the four techniques can be ranked as follows based on the mechanical properties evaluated in this study (in decreasing order): SLM, ML/PS, casting (CS), and ML.
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Brand Name | Manufacturing Method (Group Code) | Manufacturer | Elemental Composition (wt %) * | |||||||
---|---|---|---|---|---|---|---|---|---|---|
Co | Cr | W | Nb | V | Mo | Si | Fe | |||
StarLoy C | Casting (CS) | DeguDent, Hanau-Wolfgang, Germany | 59.4 | 24.5 | 10 | 2 | 2 | 1 | 1 | 0.1 |
Magnum Lucens | Milling (ML) | MESA di Sala Giacomo and C. S.n.c, Travagliato, Italy | 63 | 28 | 3 | 4 | N/A | <1 | 1 | <1 |
Remanium® star CL | Selective laser melting (SLM) | Dentaurum GmbH and Co. KG, Ispringen, Germany | 60.5 | 28 | 9 | <1 | N/A | N/A | 1.5 | <1 |
Soft Metal™ | Milling/post-sintering (ML/PS) | LHK, Chilgok, Korea | 63 | 29 | N/A | N/A | N/A | 6 | <1 | N/A |
Group | Point | Element (wt %) | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
Co | Cr | W | Nb | V | Mo | Si | Mn | C | ||
(a) CS | 1 | 65.36 | 23.50 | 7.41 | 0.84 | 1.65 | 0.82 | 0.42 | - | - |
2 | 54.03 | 22.01 | 13.92 | 4.06 | 1.50 | 1.82 | 0.79 | - | 1.87 | |
3 | 49.34 | 15.68 | 17.78 | 9.74 | 0.93 | 2.78 | 1.66 | - | 2.09 | |
(b) ML | 1 | 65.23 | 31.63 | 1.67 | 0.86 | - | - | 0.61 | - | - |
2 | 50.80 | 14.98 | 3.98 | 27.70 | - | - | 2.54 | - | - | |
3 | 34.60 | 13.43 | 3.16 | 46.04 | - | - | 2.77 | - | - | |
(c) SLM | 1 | 71.33 | 22.56 | 4.70 | - | - | - | 0.82 | 0.58 | -. |
(d) ML/PS | 1 | 67.12 | 26.20 | - | - | - | 4.68 | 0.60 | - | 1.41 |
2 | 17.16 | 66.64 | - | - | - | 9.39 | - | - | 6.80 |
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Kim, H.R.; Jang, S.-H.; Kim, Y.K.; Son, J.S.; Min, B.K.; Kim, K.-H.; Kwon, T.-Y. Microstructures and Mechanical Properties of Co-Cr Dental Alloys Fabricated by Three CAD/CAM-Based Processing Techniques. Materials 2016, 9, 596. https://doi.org/10.3390/ma9070596
Kim HR, Jang S-H, Kim YK, Son JS, Min BK, Kim K-H, Kwon T-Y. Microstructures and Mechanical Properties of Co-Cr Dental Alloys Fabricated by Three CAD/CAM-Based Processing Techniques. Materials. 2016; 9(7):596. https://doi.org/10.3390/ma9070596
Chicago/Turabian StyleKim, Hae Ri, Seong-Ho Jang, Young Kyung Kim, Jun Sik Son, Bong Ki Min, Kyo-Han Kim, and Tae-Yub Kwon. 2016. "Microstructures and Mechanical Properties of Co-Cr Dental Alloys Fabricated by Three CAD/CAM-Based Processing Techniques" Materials 9, no. 7: 596. https://doi.org/10.3390/ma9070596