scholarly journals Influence of the Infill Orientation on the Properties of Zirconia Parts Produced by Fused Filament Fabrication

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3158 ◽  
Author(s):  
Santiago Cano ◽  
Tanja Lube ◽  
Philipp Huber ◽  
Alberto Gallego ◽  
Juan Alfonso Naranjo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Complex Geometries ◽  
Fused Filament Fabrication ◽  
Moisture Evaporation ◽  
Bending Tests ◽  
Three Point Bending ◽  
Different Types ◽  
Fill Pattern ◽  
The Many

The fused filament fabrication (FFF) of ceramics enables the additive manufacturing of components with complex geometries for many applications like tooling or prototyping. Nevertheless, due to the many factors involved in the process, it is difficult to separate the effect of the different parameters on the final properties of the FFF parts, which hinders the expansion of the technology. In this paper, the effect of the fill pattern used during FFF on the defects and the mechanical properties of zirconia components is evaluated. The zirconia-filled filaments were produced from scratch, characterized by different methods and used in the FFF of bending bars with infill orientations of 0°, ±45° and 90° with respect to the longest dimension of the specimens. Three-point bending tests were conducted on the specimens with the side in contact with the build platform under tensile loads. Next, the defects were identified with cuts in different sections. During the shaping by FFF, pores appeared inside the extruded roads due to binder degradation and or moisture evaporation. The changes in the fill pattern resulted in different types of porosity and defects in the first layer, with the latter leading to earlier fracture of the components. Due to these variations, the specimens with the 0° infill orientation had the lowest porosity and the highest bending strength, followed by the specimens with ±45° infill orientation and finally by those with 90° infill orientation.

Effect of Direct Electric Resistance Heat Treatment on Mechanical Properties of NiTi Orthodontic Arch Wires

2008 ◽  
Vol 55-57 ◽  
pp. 249-252 ◽  
Author(s):  
W. Kiattiwongse ◽  
Anak Khantachawana ◽  
P. Santiwong
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Bending Test ◽  
Electric Resistance ◽  
Bending Tests ◽  
Three Point Bending ◽  
Heat Treated ◽  
Different Types ◽  
Orthodontic Archwires ◽  
A Current

Two types of rectangular orthodontic archwires; NiTiTM and 40oCuNiTi, were heat treated by Direct Electric Resistance Heat Treatment (DERHT) using different electric currents for 4 s. Their mechanical properties were then evaluated by micro hardness and three-point bending tests. After applying 4.5-5.5 A current, the hardness of NiTiTM increased with the increased current, whereas the change in hardness of 40oCuNiTi was slight. When 6 A current was applied, the hardness of the midspan of both wires significantly decreased. From the three-point bending test, unloading forces of NiTiTM increased after treating with 5.5 A current, while those of 40oCuNiTi decreased. However, both specimens lost their superelasticity when applied with 6 A current. In conclusion, after DERHT, various changes in mechanical properties can be noted in the different types of nickel titanium archwire.

scholarly journals Comparison of Mechanical Properties of Hemp-Fibre Biocomposites Fabricated with Biobased and Regular Epoxy Resins

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5720 ◽  
Author(s):  
Vicente Colomer-Romero ◽  
Dante Rogiest ◽  
Juan Antonio García-Manrique ◽  
Jose Enrique Crespo
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resins ◽  
Raw Materials ◽  
Green Composites ◽  
Bending Tests ◽  
Three Point Bending ◽  
Reinforced Plastics ◽  
Structural Applications ◽  
Glass Fibre Reinforced ◽  
Glass Fibre Reinforced Plastics

Bio- and green composites are mainly used in non-structural automotive elements like interior panels and vehicle underpanels. Currently, the use of biocomposites as a worthy alternative to glass fibre-reinforced plastics (GFRPs) in structural applications still needs to be fully evaluated. In the current study, the development of a suited biocomposites started with a thorough review of the available raw materials, including both reinforcement fibres and matrix materials. Based on its specific properties, hemp appeared to be a very suitable fibre. A similar analysis was conducted for the commercially available biobased matrix materials. Greenpoxy 55 (with a biocontent of 55%) and Super Sap 100 (with a biocontent of 37%) were selected and compared with a standard epoxy resin. Tensile and three-point bending tests were conducted to characterise the hemp-based biocomposite.

Bending Strength of Al2O3 Ceramics for Textiles Machinery and Elastic Wave Characteristics by Wavelet Analysis

2007 ◽  
Vol 353-358 ◽  
pp. 345-348
Author(s):  
Ki Woo Nam ◽  
B.G. Ahn ◽  
M.K. Kim ◽  
C.S. Son ◽  
Jin Wook Kim ◽  
...  
Keyword(s):  
Elastic Wave ◽  
Bending Strength ◽  
Test Results ◽  
Composite Ceramics ◽  
Bending Tests ◽  
Three Point Bending ◽  
Wave Signal ◽  
Al2o3 Composite ◽  
Signal Characteristics ◽  
Optimized Conditions

The optimized conditions of pressureless sintering were investigated in order to obtain the bending strength and the elastic wave signal of Al2O3 composite ceramics for textiles machinery. As sintering conditions, a temperature range from 1400°C to 1700°C and time from 30 minutes to 150 minutes were applied. Three-point bending tests were conducted on the sintered materials to obtain the strength property. From the test results, the optimum sintering condition was 1600°C, 100 minutes. Al2O3 composite ceramics showed that the elastic wave signal characteristics had a regular correlativity between the optimum sintering temperature and time as well as the maximum bending strength.

Fabrication of Composite Blocks Containing Alumina Bubble Particles for Porous CBN Abrasive Wheels

2012 ◽  
Vol 499 ◽  
pp. 229-234 ◽  
Author(s):  
Q. Pan ◽  
Wen Feng Ding ◽  
Jiu Hua Xu ◽  
B. Zhang ◽  
H.H. Su ◽  
...  
Keyword(s):  
Fracture Surface ◽  
Dwell Time ◽  
Bending Strength ◽  
Ti Alloy ◽  
Abrasive Wheel ◽  
Bending Tests ◽  
Three Point Bending ◽  
Abrasive Grains ◽  
Alumina Particles ◽  
Vitrified Cbn

Alumina (Al2O3) bubble particles were added into the mixture of CBN abrasive grains, Cu-Sn-Ti alloy and graphite particles to prepare the composite blocks for porous CBN abrasive wheels. The specimens were sintered at the temperature of 920°C for the dwell time of 30 min. The bending strength of the composite blocks was measured by the three-point bending tests. The fracture surface of the blocks was characterized. The results show that, the content of alumina bubble particles does not take significant effect on the mechanical strength of the composite blocks. Even the lowest strength of the composite blocks, 98 MPa, is higher than that of the vitrified CBN abra-sive wheels. Cu-Sn-Ti alloy has bonded firmly alumina particles and CBN grains by means of the chemical reaction and corresponding products. Finally, the chip space was formed through the re-moval of the ceramic wall of the alumina bubble particles within the CBN abrasive wheel during dressing.

Effect of Moisture Absorption on the Bending Strength of CFRP

2012 ◽  
Vol 450-451 ◽  
pp. 482-485 ◽  
Author(s):  
A Ying Zhang ◽  
Di Hong Li ◽  
Dong Xing Zhang
Keyword(s):  
Moisture Content ◽  
Composite Laminates ◽  
Immersion Time ◽  
Moisture Absorption ◽  
Bending Strength ◽  
Experimental Results ◽  
Bending Tests ◽  
Three Point Bending ◽  
Damage Propagation ◽  
Effect Of Moisture

The effects of moisture content on the bending strength of T300/914 composite laminates that immersed in water for 7 days and 14 days was discussed in this paper. The three-point bending tests were conducted on the composite laminates. Experimental results reveal that the moisture content in the laminates increased with immersion time and that moisture absorption accelerated damage propagation in the composite laminates. The bending strength of the unaged, aged specimens were characterized and analyzed. Compared to the unaged specimens, the bending strength of the composite laminates immersed for 7 and 14 days decreased by 6.62% and 16.98%, respectively. The results revealed that the bending strength of the aged specimens decreased with the increasing immersion time.

Fabrication of TiAl Intermetallic by Spark Plasma Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 1050-1052 ◽  
Author(s):  
Hai Tao Wu ◽  
Yun Long Yue ◽  
Wei Bing Wu ◽  
Hai Yan Yin
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compounds ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Three Point Bending ◽  
The Poor ◽  
High Relative Density ◽  
Plasma Sintering ◽  
Spark Plasma

The γ-TiAl intermetallic compounds were produced at the temperature ranging from 850°C to 1050°C by the Spark Plasma Sintering (SPS) process. The effects of sintering temperature and holding time on the mechanical properties of γ-TiAl intermetallic compounds were investigated. The γ-TiAl intermetallic compounds sintered at 1050°C for 10 min showed a high relative density more than 98%, and had the best three-point bending strength of 643MPa, fracture toughness of 12 MPa·m1/2 and microhardness of 560MPa. The microstructural observations indicated typical characteristics of intergranular fracture, which meant the poor ductility of γ-TiAl intermetallic compounds.

Bending Properties and Failure Mechanisms of Tapered 3D Braided Composites

2011 ◽  
Vol 332-334 ◽  
pp. 1468-1471 ◽  
Author(s):  
Can Can Cheng ◽  
Zhao Lin Liu ◽  
Li Fang Liu ◽  
Jian Yong Yu
Keyword(s):  
Failure Modes ◽  
Bending Strength ◽  
Failure Mechanisms ◽  
Reduction Technique ◽  
Braided Composites ◽  
Bending Properties ◽  
Bending Tests ◽  
Three Point Bending ◽  
Bending Modulus ◽  
3D Braided Composites

Tapered 3D braided composites are prepared by column yarn-reduction technique, unit yarn-reduction technique and cutting, respectively. Bending properties in the tapered regions of the composites are obtained by three-point bending tests, and SEM photographs of the fracture surfaces are observed to analyze the failure mechanisms. Results show that bending modulus and bending strength of the yarn-reduction composites are significantly higher than those of the cut composites, and the unit yarn-reduction composites are slightly stronger than the column yarn-reduction composites. The saw-tooth propagation of matrix crackings and interfacial debondings are the primary failure mechanisms of the yarn-reduction composites, while yarn breakages and yarn pulling-outs are the main failure modes of the cut composites.

Mechanical Properties of Carbon Nanofiber Reinforced Polylactic Acid

2007 ◽  
Vol 345-346 ◽  
pp. 1225-1228 ◽  
Author(s):  
Yoshinobu Shimamura ◽  
Atushi Yamamoku ◽  
Keiichiro Tohgo ◽  
Shigeru Tasaka ◽  
Hiroyasu Araki
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Bending Strength ◽  
Carbon Nanofiber ◽  
Weight Fraction ◽  
Three Point Bending ◽  
Fracture Surfaces ◽  
Pull Out ◽  
Twin Screw ◽  
Carbon Nanofiller

Carbon nanofiller reinforced PLA was fabricated, and the mechanical properties and heat resistivity were measured. Vapor grown carbon fiber (VGCF) produced by Showa Denko K.K. was used for reinforcement, which has 150 nm in diameter and 10 μm in length. No surface treatment of VGCF was conducted. VGCF and PLA were compounded by using a twin screw extrusion machine and then pelletized. The weight fraction of VGCF ranged from 1wt% to 10wt%. Three point bending specimens were fabricated by using injection molding. At first, three point bending tests were carried out at room temperature. The bending stiffness increased from 3GPa to as high as 5GPa, but the bending strength slightly decreased. SEM observation of the fracture surfaces indicated pull-out of VGCFs over the fracture surfaces. These results imply that adhesion between VGCF and matrix was imperfect. Then, the heat deflection temperatures and glass transition temperatures of the specimens were measured. The addition of VGCF did not increase the glass transition temperature but slightly increased the heat deflection temperature.

Mechanical properties of several nickel-titanium alloy wires in three-point bending tests

1999 ◽  
Vol 115 (4) ◽  
pp. 390-395 ◽  
Author(s):  
Hirokazu Nakano ◽  
Kazuro Satoh ◽  
Robert Norris ◽  
Tomoaki Jin ◽  
Tetsuya Kamegai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Nickel Titanium ◽  
Bending Tests ◽  
Three Point Bending

Mechanical Characterizations of Saxidomus purpuratus Shells

2010 ◽  
Vol 434-435 ◽  
pp. 601-604 ◽  
Author(s):  
W. Yang ◽  
Y. Jiang ◽  
G.P. Zhang ◽  
Y.S. Chao ◽  
Xiao Wu Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Bending Strength ◽  
Target Material ◽  
Organic Matrix ◽  
Fatigue Tests ◽  
Bending Fatigue ◽  
Three Point Bending ◽  
Saxidomus Purpuratus ◽  
Scanning Electron

A sort of biological shells (Saxidomus purpuratus), which belongs to Bivalve, was selected as the target material, and hardness and dynamic three point bending fatigue tests were conducted to examine its mechanical properties. Microhardness measurements showed that the inner layer is the hardest. The indentation on the specimen with a lower bending strength was damaged more seriously by the same load. Three point bending fatigue tests demonstrated that this kind of the shells with a special structure comprising mineral and organic matrix can experience the repeated loads instead of immediate breaking. The fatigue results on a single shell investigated here indicated that the fatigue strength is usually less than the static bending strength. Most of the fatigue lives of the specimens are less than 2105 cycles. In addition, fatigue fracture surfaces are observed by scanning electron microscopy.

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