Experimental Investigation of Stratasys J750 PolyJet Printer: Effects of Orientation and Layer Thickness on Mechanical Properties

2019 ◽  
Author(s):  
Xingjian Wei ◽  
Abhinav Bhardwaj ◽  
Chin-Cheng Shih ◽  
Li Zeng ◽  
Bruce Tai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
Layer Thickness ◽  
Axial Direction ◽  
Limited Information ◽  
Direction Parallel ◽  
Control Factors ◽  
Significant Difference

Abstract The J750 PolyJet printer is the newest model of full-color, multi-material 3D printer from Stratasys. Currently, limited information is available about the effects of control factors on mechanical properties such as elastic modulus, ultimate tensile strength, and elongation. In this study, the effects of two control factors, orientation and layer thickness, on mechanical properties of samples printed by the Stratasys J750 printer are investigated. The results show that orientation significantly affects mechanical properties. Specifically, samples printed with its axial direction parallel to the direction of printing have the highest elastic modulus, and elongation, whereas samples printed with its axial direction perpendicular to the direction of printing have the highest ultimate tensile strength. Also, layer thickness makes a significant difference for mechanical properties, and larger layer thickness leads to higher ultimate tensile strength and elongation. These results would be valuable to researchers and practitioners who use J750.

High flow compression molding for recycling discontinuous long fiber thermoplastic composites

2020 ◽  
Vol 54 (23) ◽  
pp. 3343-3350
Author(s):  
Éric Léger ◽  
Benoit Landry ◽  
Gabriel LaPlante
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compression Molding ◽  
High Flow ◽  
Low Flow ◽  
Thermoplastic Composites ◽  
Direction Parallel ◽  
Significant Difference ◽  
Long Fiber Thermoplastic ◽  
Flow Compression

An investigation into high flow compression molding for recycling thermoplastic discontinuous long fiber composites is presented. High flow recycled panels and conventional low flow baseline panels were produced with a large rectangular (2:1 aspect ratio) mold. Flow was induced in the recycled panels by stacking cut sections of conventionally produced baseline panels in the center of the mold cavity, representing 25% initial coverage. High flow compression molded panels were found to exhibit significantly higher than baseline tensile strength (+50%) and modulus (+31%) when tested in the direction parallel to flow. When tested in the direction perpendicular to flow, the opposite effect was found, with reductions in tensile strength (−42%) and modulus (−37%). However, when the average results of both directions are compared to baseline, no significant difference was found between the recycled and baseline panels. This severe anisotropic redistribution of mechanical properties suggests chip orientation is affected by flow. Additionally, micrographic analysis revealed that high flow molding induces intra-ply chip shearing and a reduction in resin rich regions within panels. Baseline panels also exhibited in-plane anisotropy, despite initial random distribution of chips and no or near no flow induced during molding. In this case, mechanical properties favored the direction perpendicular to that of the recycled panels.

scholarly journals Kearns texture parameters, mechanical properties and damageability of titanium sheet after alternating bending

2021 ◽  
Vol 22 (3) ◽  
pp. 543-550
Author(s):  
V.V. Usov ◽  
N.M. Shkatulyak ◽  
O.S. Savchuk ◽  
N.I. Rybak
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
Yield Stress ◽  
Rolling Direction ◽  
Initial State ◽  
Texture Parameters ◽  
Experimental Values ◽  
Alternating Bending

This work aims to determine the Kearns texture parameters and evaluate on their basis the elastic moduli, mechanical properties (ultimate tensile strength, conditional yield stress), as well as damageability parameters of the sheets commercial titanium (CT-grade 1: 0.04% Fe; 0.015% C; 0.05% N 0.05% c; 0.009% H)  as delivered after rolling and annealing at 840°C (original sheet) and further alternating bending (AB) in the amount of 0.5; 1, 3 and 5 cycles. Damageability parameters characterizing damage accumulation were determined from the elastic modulus change after the above-mentioned number of AB cycles relative to the values ​​of the elastic modulus in different directions of the original sheet of the studied titanium. The elastic constants of the single crystal and the Kearns texture parameters were used to estimate the elastic modulus in the rolling direction (RD) and transverse direction (TD) of the original sheet, and sheets after an above number of AB cycles. The deviation of the calculated and experimental values ​​of the elastic modulus did not exceed 5%. The deviation of the calculated and experimental values of the ultimate tensile strength and yield stress in the RD and TD both in the initial state and after the corresponding number cycles of the AB did not exceed 10%.

scholarly journals Mechanical Properties of Laser-Sintered 3D-Printed Cobalt Chromium and Soft-Milled Cobalt Chromium

Prosthesis ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 313-320
Author(s):  
Abdullah Barazanchi ◽  
Kai Chun Li ◽  
Basil Al-Amleh ◽  
Karl Lyons ◽  
J. Neil Waddell
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
High Stress ◽  
Uniform Structure ◽  
Cobalt Chromium ◽  
Proof Stress ◽  
Fracture Surfaces ◽  
3D Printed

Purpose: To compare the mechanical properties and fracture behaviour of laser-sintered/3D-printed cobalt chromium (LS CoCr) with soft-milled cobalt chromium (SM CoCr) to assess their suitability for use in high-stress areas in the oral cavity. Material and Method: Two computer-aided manufacturing methods were used to fabricate dumbbell specimens in accordance with the ASTM standard E8. Specimens were fractured using tensile testing and elastic modulus, and proof stress and ultimate tensile strength were calculated. Fracture surfaces were examined using scanning electron microscopy. Plate specimens were also fabricated for the examination of hardness and elastic modulus using nanoindentation. Unpaired t-test was used to evaluate statistical significance. Results: LS CoCr specimens were found to have significantly higher ultimate tensile strength (UTS) and proof stress (PS) (p < 0.05) but not a significantly higher elastic modulus (p > 0.05). Examination of the dumbbell fracture surfaces showed uniform structure for the LS CoCr specimens whilst the SM CoCr specimens were perforated with porosities; neither showed an obvious point of fracture. Nanoindentation also showed that LS CoCr specimens possessed higher hardness compared with SM CoCr specimens. Conclusion: LS CoCr and SM CoCr specimens were both found to exhibit uniformly dense structure; although porosities were noted in the SM CoCr specimens. LS CoCr specimens were found to have superior tensile properties, likely due to lack of porosities, however both had mean values higher than those reported in the literature for cast CoCr. Uniformity of structure and high tensile strength indicates that LS CoCr and SM CoCr fabricated alloys are suitable for long-span metallic frameworks for use in the field of prosthodontics.

Effect of Preheating and Fatiguing on Mechanical Properties of Bulk-fill and Conventional Composite Resin

2019 ◽  
Vol 45 (4) ◽  
pp. 387-395
Author(s):  
AA Abdulmajeed ◽  
TE Donovan ◽  
R Cook ◽  
TA Sulaiman
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Composite Resin ◽  
Statistical Significance ◽  
Composite Resins ◽  
Significant Difference ◽  
Diametral Tensile Strength

Clinical Relevance Bulk-fill composite resins may have comparable mechanical properties to conventional composite resin. Preheating does not reduce the mechanical properties of composite resins. SUMMARY Statement of Problem: Bulk-fill composite resins are increasingly used for direct restorations. Preheating high-viscosity versions of these composites has been advocated to increase flowability and adaptability. It is not known what changes preheating may cause on the mechanical properties of these composite resins. Moreover, the mechanical properties of these composites after mastication simulation is lacking. Purpose: The purpose of this study was to evaluate the effect of fatiguing and preheating on the mechanical properties of bulk-fill composite resin in comparison to its conventional counterpart. Methods and Materials: One hundred eighty specimens of Filtek One Bulk Fill Restorative (FOBR; Bulk-Fill, 3M ESPE) and Filtek Supreme Ultra (FSU; Conventional, 3M ESPE) were prepared for each of the following tests: fracture toughness (International Organization for Standardization, ISO 6872), diametral tensile strength (No. 27 of ANSI/ADA), flexural strength, and elastic modulus (ISO Standard 4049). Specimens in the preheated group were heated to 68°C for 10 minutes and in the fatiguing group were cyclically loaded and thermocycled for 600,000 cycles and then tested. Two-/one-way analysis of variance followed by Tukey Honest Significant Difference (HSD) post hoc test was used to analyze data for statistical significance (α=0.05). Results: Preheating and fatiguing had a significant effect on the properties of both FSU and FOBR. Fracture toughness increased for FOBR specimens when preheated and decreased when fatigued (p=0.016). FOBR had higher fracture toughness value than FSU. Diametral tensile strength decreased significantly after fatiguing for FSU (p=0.0001). FOBR had a lower diametral tensile strength baseline value compared with FSU (p=0.004). Fatiguing significantly reduced the flexural strength of both FSU and FOBR (p=0.011). Preheating had no effect on the flexural strength of either FSU or FOBR. Preheating and fatiguing significantly decreased the elastic modulus of both composite resins equally (p&gt;0.05). Conclusions: Preheating and fatiguing influenced the mechanical properties of composite resins. Both composites displayed similar mechanical properties. Preheating did not yield a major negative effect on their mechanical properties; the clinical implications are yet to be determined.

Microstructure and Mechanical Properties of TRIP-Aided Steels with Different Heat Treatments

2015 ◽  
Vol 817 ◽  
pp. 439-443 ◽  
Author(s):  
Rui Dong ◽  
Ai Min Zhao ◽  
Ran Ding ◽  
Jian Guo He ◽  
Han Jiang Hu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Total Elongation ◽  
Heat Treatments ◽  
Second Phase ◽  
Soft Matrix ◽  
Significant Difference

The microstructures, mechanical properties and retained austenite characteristics of TRIP-aided steels with three different heat treatments were studied in this paper. The results indicated that the designed annealing treatments resulted in completely different matrices and the morphologies of second phase, and a significant difference in mechanical properties. The TAM steel was found to have fine annealed martensite lath matrix and inter lath acicular retained austenite, and possessed an excellent combination of strength and elongation which attributed to the highest retained austenite volume fraction and carbon concentration. For TPF steel, the higher instability and lower carbon content of retained austenite and the soft matrix resulted in the lowest ultimate tensile strength and total elongation. While in TBF steel, the stability of retained austenite was lower than that in TAM steel but higher than that in TPF steel. The ultimate tensile strength of TBF was significantly higher than the TAM and TPF steels, but the ductility of TBF steel was lower than TAM steel.

scholarly journals Tensile properties of PLA/PBAT blends and PLA fibre-reinforced PBAT composite

2018 ◽  
Vol 192 ◽  
pp. 03014 ◽  
Author(s):  
Eakasit Sritham ◽  
Phakaimat Phunsombat ◽  
Jedsada Chaishome
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
Tensile Properties ◽  
Room Temperature ◽  
Dsc Measurements ◽  
Significant Difference ◽  
Two Phases

The tensile properties of PLA/PBAT blends, PLA fibre reinforced PBAT composite (PLAF) at room temperature and -18°C were investigated. The concentrations of PLA in the blends were 10%, 20%, 30% and 40% (by volume). There was an improvement of elastic modulus (E) for PLA/PBAT blends when PLA was 40%. There was no significant difference of ultimate tensile strength (UTS) among the blends. For the same concentration of PLA (40%) in PLA-PBAT mixture, PLAF exhibited higher values of E and UTS than that of PLA/PBAT blends. Elongation of PLA/PBAT blends rapidly decreased upon the addition of PLA to the blends. The values of E and UTS for PLA/PBAT blends and composite, neat PLA, and PP increased with the decreasing of temperature from room temperature to -18°C. The effect of decreasing temperature was not observed on elongation. It was appeared from the results obtained for FTIR and DSC measurements that PLA and PBAT were immiscible, separating into two phases.

Recycling of Radiation Crosslinked Polyamide 6

2015 ◽  
Vol 752-753 ◽  
pp. 331-336
Author(s):  
Jan Navratil ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
David Manas ◽  
Martin Bednarik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
Impact Toughness ◽  
High Density Polyethylene ◽  
Polyamide 6 ◽  
High Density ◽  
Material Stiffness ◽  
Plastic Materials

Growing usage of radiation crosslinked plastic materials and utilization of their advantageous properties might raise a question of their future recycling. This paper deals with utilization of recycled irradiated polyamide 6 (rPA6x) which is used as a filler into low and high-density polyethylene (LDPE/HDPE) in concentrations 10 and 30 %. Mechanical properties of such blends were investigated and compared. Both blends show similar trend at all observed material characteristics. Elastic modulus representing material stiffness grown with increasing amount of the filler. Ultimate tensile strength and impact toughness decreased and hardness slightly increased. All the obtained results show that it is possible to use recycled radiation crosslinked PA6 as a filler but it is necessary to count with properties change.

scholarly journals Modified Osgood Equation for Acacia Mangium

2019 ◽  
pp. 33-35
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Acacia Mangium ◽  
Tensile Tests ◽  
Test Results ◽  
Direction Parallel ◽  
Static Testing ◽  
Significant Difference ◽  
Static Tensile ◽  
Wood Grain

The purpose of this study is to identify the Osgood’s coefficient of species and the Modified Osgood Equation for Acacia mangium. Acacia mangium trees were cut to produce oven-dried Small Clear Specimens that were then tested until fracture. Results were gathered from static tensile tests in the direction parallel (0° angle), perpendicular (90° angle) and at 30° angle to the wood grain. All test results confirmed that the Acacia mangium wood is brittle as there was no obvious necking observed on the test specimens. From the static testing, the Osgood’s coefficient of species for Acacia mangium, (a), is identified algebraically to be 0.49. Acacia mangium, by nature, has a significant difference in the strengths parallel and perpendicular to the grain line. The finalized results of the Ultimate Tensile Strength for 15-year old Acacia mangium demonstrated that the Ultimate Tensile Strength in parallel and perpendicular to the grain directions are 143.87 MPa and 6.32 MPa respectively, while the Ultimate Tensile Strength at 30° grain angle is 32.985 MPa. An extreme reduction of 95.6% of the Ultimate Tensile Strength was identified between 0° and 90° grain angles with a decreased value from 143.87 MPa to 6.32 MPa.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

scholarly journals Effects of Substitution of Y with Yb and Ce on the Microstructures and Mechanical Properties of Mg88.5Zn5Y6.5

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Long Period ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.

Sign in / Sign up

Export Citation Format

Share Document