Additively Manufactured Commercial Co-Cr Dental Alloys: Comparison of Microstructure and Mechanical Properties

Laser-powder bed fusion (LPBF) is one of the preferred techniques for producing Co-Cr metal structures for dental prosthodontic appliances. However, there is generally insufficient information about material properties related to the production process and parameters. This study was conducted on samples produced from three different commercially available Co-Cr dental alloys produced on three different LPBF machines. Identically prepared samples were used for tensile, three-point bending, and toughness tests. Light microscopy (LM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) analyses of microstructure were performed after testing. Differences were observed in microstructures, which reflected statistically significant differences in mechanical properties (one-way analysis of variance (ANOVA) and Scheffé post hoc test (α = 0.05)). The material produced on the 3D Systems DMP Dental 100 had 24 times greater elongation ε than the material produced on the Sysma MySint 100 device and the EOS M100 machine. On the other hand, the material produced on the EOS M100 had significantly higher hardness (HV0.2) than the other two produced materials. However, the microstructure of the Sysma specimens with its morphology deviates considerably from the studied group. LPBF-prepared Co-Cr dental alloys demonstrated significant differences in their microstructures and, consequently, mechanical properties.

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Investigation of the Deformation Twins on the Bending Cross Section of TA2 Titanium Sheet

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.837.41 ◽

2020 ◽

Vol 837 ◽

pp. 41-45

Author(s):

Shuai Sun ◽

Kai Hua Liu

Keyword(s):

Electron Backscatter Diffraction ◽

Testing Machine ◽

Pure Titanium ◽

Titanium Sheet ◽

Bending Tests ◽

Three Point Bending ◽

Deformation Twins ◽

Ebsd Technique ◽

Backscatter Diffraction ◽

Deformation Area

In order to determine the evolution features of deformation twins for TA2 commercial pure titanium (cp-TA2), the TA2 samples were bent under different bending angles in three-point bending tests via a universal testing machine. The electron backscatter diffraction (EBSD) technique was applied to identify the grain boundaries (GBs) and twin boundaries (TBs) in the bending areas. The results reveal that the type of deformation area would effect the evolution of different deformation twins. It is inferred that the state of stress would promote the multiplication of the same type of deformation twins.

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Correlation of Strain Path, Texture, Twinning, and Mechanical Properties in Twinning-Induced Plasticity Steel during Wire Drawing

Materials ◽

10.3390/ma13102250 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2250 ◽

Cited By ~ 1

Author(s):

Joong-Ki Hwang

Keyword(s):

Mechanical Properties ◽

Strain Path ◽

Electron Backscatter Diffraction ◽

Steel Wire ◽

Effective Strain ◽

Metal Flow ◽

Wire Drawing ◽

Surface Areas ◽

The Wire ◽

Backscatter Diffraction

The effect of changing the strain path on texture development, twin kinetics, and mechanical properties in twinning-induced plasticity steel was investigated to understand twinning behavior in more detail. Among the various plastic deformation processes, the wire drawing process was selected to achieve the aims of the study. Specimens of cold-drawn TWIP steel wire under the same effective strain but with different crystallographic textures were successfully fabricated using the effect of the wire drawing direction. Electron backscatter diffraction results showed that the drawn wires using both unidirectional (UD) and reverse-directional (RD) wire drawing processes were characterized as duplex fiber textures of major <111> and minor <100>. It was found that the RD wire had a higher fraction of <111> component at both the center and surface areas compared to the UD wire, because the metal flow of the RD wire was beneficial for the development of a <111> orientation. The pronounced <111> crystallographic orientation of the RD wire activated the twinning rate and geometrically necessary dislocation density, leading to an increase in strength but a decrease in ductility. The strain path is as important as the amount of strain for strengthening the materials, especially those that are deformed by twinning.

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Microstructure and Mechanical Properties of Ti Cold-Spray Splats Determined by Electron Channeling Contrast Imaging and Nanoindentation Mapping

Microscopy and Microanalysis ◽

10.1017/s1431927615000240 ◽

2015 ◽

Vol 21 (3) ◽

pp. 570-581 ◽

Cited By ~ 21

Author(s):

Dina Goldbaum ◽

Richard R. Chromik ◽

Nicolas Brodusch ◽

Raynald Gauvin

Keyword(s):

Mechanical Properties ◽

Cold Spray ◽

Electron Backscatter Diffraction ◽

Substrate Material ◽

Contrast Imaging ◽

Electron Channeling ◽

Metallurgical Bonding ◽

Resolution Electron ◽

Backscatter Diffraction ◽

The Impact

AbstractCold spray is a thermo-mechanical process where the velocity of the sprayed particles affects the deformation, bonding, and mechanical properties of the deposited material, in the form of splats or coatings. At high strain rates, the impact stresses are converted into heat, a phenomenon known as adiabatic shear, which leads to grain re-crystallization. Grain re-crystallization and growth are shown to have a direct impact on the mechanical properties of the cold-sprayed material. The present study ties the microstructural features within the cold-sprayed Ti splats and the substrate to the bonding mechanism and mechanical properties. High-resolution electron channeling contrast imaging, electron backscatter diffraction mapping, and nanoindentation were used to correlate the microstructure to the mechanical properties distribution within the titanium cold-spray splats. The formation of nanograins was observed at the titanium splat/substrate interface and contributed to metallurgical bonding. An increase in grain re-crystallization within the splat and substrate materials was observed with pre-heating of the substrate. In the substrate material, the predominant mechanism of deformation was twinning. A good relationship was found between the hardness and distribution of the twins within the substrate and the size distribution of the re-crystallized grains within the splats.

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Microstructural Evolutions and Mechanical Properties of Drawn Medium Carbon Steel Wire

International Journal of Engineering Research in Africa ◽

10.4028/www.scientific.net/jera.41.1 ◽

2019 ◽

Vol 41 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Mohamed Chaouki Nebbar ◽

Mosbah Zidani ◽

Toufik Djimaoui ◽

T. Abid ◽

Hichem Farh ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Steel ◽

Electron Backscatter Diffraction ◽

Texture Evolution ◽

Steel Wire ◽

Wire Drawing ◽

Medium Carbon Steel ◽

X Ray Diffraction ◽

Medium Carbon ◽

Backscatter Diffraction

This study focuses on the evolution in the microstructure, texture and mechanical properties of medium carbon steel wires obtained by wire drawing at Tréfissoud Company for the manufacturing of the spring mattress. Wire drawing induces elongation of grains in the direction of drawing with the development of the <110> fibre texture parallel to the wire axis. Kinking and bending of cementite lamellae were observed during the drawing process. The work was carried out respectively on three states, wire rod and drawn states for two different amounts (ε %=43,6 and 60 %), using the optical and SEM microscopy, electron backscatter diffraction and X-ray diffraction analysis for examination of the microstructure and texture evolution, the hardness Vickers and tensile test to follow the curing of the studied wires.

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Research on the Microstructures and Mechanical Properties of Bainite/Martensite Rail Treated by the Controlled-Cooling Process

Materials ◽

10.3390/ma12193061 ◽

2019 ◽

Vol 12 (19) ◽

pp. 3061 ◽

Cited By ~ 3

Author(s):

Jiajia Qiu ◽

Min Zhang ◽

Zhunli Tan ◽

Guhui Gao ◽

Bingzhe Bai

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Tensile Strength ◽

Impact Toughness ◽

Electron Backscatter Diffraction ◽

Microstructural Characterization ◽

Cooling Process ◽

Controlled Cooling ◽

Transmission Electron ◽

Backscatter Diffraction

A bainite/martensite multiphase rail is treated by the controlled-cooling process with different finish-cooling temperatures. The simulated temperature–time curves of the position of 5 mm and 15 mm below the rail tread (P5 and P15) express different trends. P5 has greater impact toughness and lower tensile strength than P15. Microstructural characterization was carried out by conducting scanning electron microscopy, X-ray diffraction, electron backscatter diffraction, and transmission electron microscopy. The greater tensile strength is due to the dispersed ε-carbides hindering the movement of dislocations. The greater impact toughness is attributed to the filmy retained austenite and the smaller effective grain with high-angle boundary. Finite element modeling (FEM) and microstructural characterization reasonably explain the changes of mechanical properties. The present work provides experimental and theoretical guidance for the development of rail with excellent mechanical properties.

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Structure / Property (Constitutive and Dynamic Strength / Damage) Behavior of Additively Manufactured Tantalum

EPJ Web of Conferences ◽

10.1051/epjconf/201818303002 ◽

2018 ◽

Vol 183 ◽

pp. 03002

Author(s):

George.T. Gray ◽

Veronica Livescu ◽

Cameron Knapp ◽

David R. Jones ◽

Saryu Fensin ◽

...

Keyword(s):

Mechanical Behavior ◽

Damage Evolution ◽

Electron Backscatter Diffraction ◽

Dynamic Strength ◽

Functional Requirements ◽

Structure Property ◽

Powder Bed ◽

Static Mechanical ◽

Backscatter Diffraction ◽

Dynamic Damage

For Certification and qualification of an engineering component generally involves meeting engineering and physics requirements tied to its functional requirements. In this paper, the results of a study quantifying the microstructure, mechanical behavior, and the dynamic damage evolution of Tantalum (Ta) fabricated using an EOS laser-powder-bed machine are presented. The microstructure and quasi-static mechanical behavior of the AM-Ta is detailed and compared / contrasted to wrought Ta. The dynamic damage evolution and failure response of the AM-Ta material, as well as wrought Ta, was probed using flyer-plate impact driven spallation experiments. The differences in the spallation response between the AM and wrought Ta were measured using in-situ velocimetry as well as post-mortem quantification of damage in “soft-recovered” samples. The damage evolution of the AM and wrought Ta were characterized using both optical metallography and electron-backscatter diffraction.

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Development of Asymmetric Rolling for the Better Control over Structure and Mechanical Properties in IF Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.706-709.2788 ◽

2012 ◽

Vol 706-709 ◽

pp. 2788-2793 ◽

Cited By ~ 7

Author(s):

Dmitry Orlov ◽

Rimma Lapovok ◽

László S. Tóth ◽

Ilana B. Timokhina ◽

Peter D. Hodgson ◽

...

Keyword(s):

Mechanical Properties ◽

Electron Backscatter Diffraction ◽

Tensile Tests ◽

Experimental Investigations ◽

If Steel ◽

Asymmetric Rolling ◽

Electron Backscatter ◽

Strain Components ◽

Backscatter Diffraction ◽

Crystallographic Orientations

In the present study, the effects of kinematic and geometric asymmetries in rolling during multi-pass processing of IF steel are examined. The theoretical investigation by final element simulations and experimental investigations by means of electron-backscatter diffraction analysis and tensile tests suggest that asymmetric rolling increases the total imposed strain compared to symmetric rolling, and largely re-distributes the strain components due to additional shear. This enhances the intensity of grain refinement, strengthens and tilts crystallographic orientations, and increases mechanical strength. The effect is highest in the asymmetric rolling with differential roll diameters.

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Influence of Continuous Annealing Temperature on Mechanical Properties and Texture of Battery Shell Steel

Metals ◽

10.3390/met10010052 ◽

2019 ◽

Vol 10 (1) ◽

pp. 52 ◽

Cited By ~ 1

Author(s):

Beijia Ning ◽

Zhengzhi Zhao ◽

Zhiying Mo ◽

Hong Wu ◽

Chong Peng ◽

...

Keyword(s):

Mechanical Properties ◽

Annealing Temperature ◽

Electron Backscatter Diffraction ◽

Continuous Annealing ◽

Normal Anisotropy ◽

Fracture Elongation ◽

Anisotropy Index ◽

R Value ◽

Backscatter Diffraction ◽

Annealing Experiments

To study the influences of continuous annealing temperature on microstructure, mechanical properties and textures of battery shell steel, continuous annealing experiments were conducted at 710 °C, 730 °C, 760 °C and 780 °C respectively. The mechanical properties and normal anisotropy index (r) were measured by tensile test and the textures were investigated using the method of electron backscatter diffraction (EBSD). The results show that as annealing temperature rose, the grain size, fracture elongation and r value increased, whereas the strength and yield ratio decreased. The yield strength was 122 MPa, the tensile strength was 286 MPa, meanwhile the elongation and r value arrived at 38.8% and 2.3 when the annealing temperature rose to 780 °C. After annealing, the main texture in battery shell steel is {111} <112>, followed by {111} <110>. With the increase of annealing temperature, textures in {001} crystallographic plane weakened while textures in {111} plane strengthened, which is beneficial to the deep drawability of the steel.

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Effect of Al on the microstructure, corrosion behavior and mechanical properties of Mg-4Li

Anti-Corrosion Methods and Materials ◽

10.1108/acmm-06-2019-2146 ◽

2020 ◽

Vol 67 (1) ◽

pp. 31-37

Author(s):

Cheng Zhang ◽

Liang Wu ◽

Zilong Zhao ◽

Guangsheng Huang ◽

Bin Jiang ◽

...

Keyword(s):

Mechanical Properties ◽

Corrosion Behavior ◽

Design Methodology ◽

Electron Backscatter Diffraction ◽

Tensile Tests ◽

Content Type ◽

Solid Solution Strengthening ◽

Corrosion Behaviors ◽

Solution Strengthening ◽

Backscatter Diffraction

Purpose This paper aims to investigate microstructure, corrosion behavior and mechanical properties of Mg-4Li and Mg-4Li-3Al. Design/methodology/approach The microstructure was characterized by using scanning electron microscopy and electron backscatter diffraction. The corrosion behaviors were measured by hydrogen evolution and potentiodynamic polarization tests. The mechanical properties were evaluated by tensile tests. Findings The addition of Al results in the precipitation of some Mg-Al phase and Al3Li phase particles, and the formation of some fine recrystallized grains. Originality/value Mg-4Li-3Al showed a higher corrosion rate than that of Mg-4Li, attributed to the precipitate particles in Mg-4Li-3Al causing microgalvanic corrosion and the change of grain orientation. The addition of 3 Wt. per cent Al increased the tensile strength by solid solution strengthening, precipitation strengthening, refinement strengthening and texture strengthening, whilst the elongation decreased by almost half.

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