scholarly journals Composite Material of PDMS with Interchangeable Transmittance: Study of Optical, Mechanical Properties and Wettability

2021 ◽  
Vol 5 (4) ◽  
pp. 110
Author(s):  
Flaminio Sales ◽  
Andrews Souza ◽  
Ronaldo Ariati ◽  
Verônica Noronha ◽  
Elder Giovanetti ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Room Temperature ◽  
Casting Process ◽  
Optical Characteristics ◽  
Smart Devices ◽  
Superhydrophobic Coating ◽  
Gravity Casting ◽  
High Flexibility ◽  
Physical And Chemical

Polydimethylsiloxane (PDMS) is a polymer that has attracted the attention of researchers due to its unique properties such as transparency, biocompatibility, high flexibility, and physical and chemical stability. In addition, PDMS modification and combination with other materials can expand its range of applications. For instance, the ability to perform superhydrophobic coating allows for the manufacture of lenses. However, many of these processes are complex and expensive. One of the most promising modifications, which consists of the development of an interchangeable coating, capable of changing its optical characteristics according to some stimuli, has been underexplored. Thus, we report an experimental study of the mechanical and optical properties and wettability of pure PDMS and of two PDMS composites with the addition of 1% paraffin or beeswax using a gravity casting process. The composites’ tensile strength and hardness were lower when compared with pure PDMS. However, the contact angle was increased, reaching the highest values when using the paraffin additive. Additionally, these composites have shown interesting results for the spectrophotometry tests, i.e., the material changed its optical characteristics when heated, going from opaque at room temperature to transparent, with transmittance around 75%, at 70 °C. As a result, these materials have great potential for use in smart devices, such as sensors, due to its ability to change its transparency at high temperatures.

Grain Size Dependence of Tensile Properties in Cu-Sn Thin Foils (Experimental Study)

2015 ◽  
Vol 736 ◽  
pp. 19-23
Author(s):  
Taek Kyun Jung ◽  
Hyo Soo Lee ◽  
Hyouk Chon Kwon
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Experimental Study ◽  
Grain Size ◽  
Yield Strength ◽  
Room Temperature ◽  
Size Dependence ◽  
Yield Drop ◽  
Thin Foils ◽  
Vacuum Atmosphere

This study was carried out to investigate the effects of grain size on mechanical properties in Cu-Sn foil with a thickness of 30 um. The grain size was varied from approximately 7 um to 50 um using heat treatment at 773 K for 2 h to 24 h in a vacuum atmosphere. Tensile test was carried out at room temperature with strain rate of 1mm/min. Typical yield drop phenomenon was observed. Mechanical properties were found to be strongly affected by microstructural features including grain size. The yield strength and tensile strength gradually decreased with increasing the grain size. The strain to fracture also decreased by grain growth. These results could be explained by not only the grain size dependence of yield strength but also the ratio of thickness to grain size dependence of yield strength.

Microstructure and Mechanical Properties of Extruded Mg-Zn-Nd-Y-Zr-Ca Alloy

2005 ◽  
Vol 488-489 ◽  
pp. 385-388
Author(s):  
Qiang Li ◽  
Qu Dong Wang ◽  
Xiao Qing Zeng ◽  
Wen Jiang Ding ◽  
Quanbo Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Elevated Temperature ◽  
Room Temperature ◽  
Cast Alloy ◽  
Casting Process ◽  
Elevated Temperature Strength ◽  
The Matrix ◽  
Zr Alloys

Nd, Y and Ca containing Mg-Zn-Zr alloys are produced by electromagnetic direct-chilling casting process, and extruded at a temperature of 643K with two extrusion ratios of 38:1 and 22:1, respectively. The grain size is markedly reduced from 80µm in as-cast alloy to 2~5µm in as-extruded alloy due to dynamic recrystallization, and lamellar eutectics at grain boundaries in as-cast alloy are broken up and fine precipitates in the matrix come forth during hot extrusions. Mechanical properties of the alloys are measured by tensile test from room temperature to 523K. Nd, Y and Ca are favorable to the strength of the hot-extruded alloy, especially the elevated-temperature strength, which is above 200MPa in ultimate tensile strength at 523K.

Experimental Study on Mechanical Properties of Heated Granite under Different Cooling Ways

2013 ◽  
Vol 774-776 ◽  
pp. 1281-1286 ◽  
Author(s):  
Jing Ni ◽  
You Liang Chen ◽  
Peng Wang ◽  
Rafig Azzam
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Room Temperature ◽  
Heating Temperature ◽  
Peak Strain ◽  
Water Cooling ◽  
Longitudinal Wave Velocity ◽  
Slow Cooling ◽  
Axial Compressive Strength ◽  
Fast Cooling

The mechanical properties of heated granite subjected to two different cooling ways, namely cooled in the water (fast-cooling) and cooled in the air (slow-cooling) at room temperature, were studied respectively. The effects of the heating temperatures and cooling ways on the failure mode and failure mechanism of heated granite were analyzed. The tested results indicated that the longitudinal wave velocity, uni-axial compressive strength, and initial elastic modulus of heated granite decreased with the increasing heating temperature, especially for those subjected to the fast-cooling way compared to those subjected to slow-cooling way. To the contrary, the peak strain increased as the heating temperature increases, and the peak strain was bigger for the slow-cooling way than for the fast-cooling way. The analysis of the experimental results indicated that the water cooling accelerated the deterioration of the internal structure of heated granite and resulted in undesired mechanical properties.

scholarly journals Effect of Ca Concentration on Microstructure and Mechanical Properties of As-Cast and As-Extruded Quasicrystal-Strengthened Mg-7.2Zn-2.4Gd Alloy

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Jianchun Sun ◽  
Yilong Ma ◽  
Hongwei Miao ◽  
Kejian Li ◽  
Chunhong Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Grain Size ◽  
Rare Earth ◽  
Room Temperature ◽  
Earth Element ◽  
Extrusion Ratio ◽  
Gravity Casting ◽  
Ca Addition ◽  
Cast Alloys

Quasicrystal-strengthened Mg-Zn-RE (RE = rare-earth element) alloys have been investigated extensively due to their excellent mechanical properties. Here, we prepare quasicrystal-strengthened Mg-7.2Zn-2.4Gd (wt.%) alloy with different concentrations of Ca addition (0, 0.16, 0.32, and 0.64 wt.%) by traditional gravity casting, followed by extrusion at 573 K with the extrusion ratio of 9 : 1. The microstructure and room temperature tensile properties of as-cast and as-extruded alloys are characterized. With the addition of the trace amount of Ca, the I-phase tends to transfer into W-phase due to the appearance of Mg2Ca and Mg6Zn3Ca2. As a consequence, the mechanical properties of the as-cast Ca containing alloys are downgraded. After extrusion, in comparison to the as-cast alloys, microstructure of the four types of alloys is refined and mechanical property is enhanced greatly. With the increasing of Ca concentration, the grain size is decreased gradually. However, the yield strength of the alloys is decreased to about 230 MPa and then up to 269 MPa, while the elongation increases first from 12.9% to 13.6% yet then decreases to 9.9%.

The Effects of Two-Step Solution Heat Treatment of Al-6Si-2Cu Alloy for Lightweight Automotive on Mechanical Properties

2015 ◽  
Vol 1110 ◽  
pp. 158-162
Author(s):  
Seung Pyo Hong ◽  
Chung Seok Kim
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Inductively Coupled Plasma ◽  
Solution Heat Treatment ◽  
Microstructural Characterization ◽  
Casting Process ◽  
Optical Microscope ◽  
Intermetallic Phases ◽  
Single Step ◽  
Gravity Casting

The effects of two-step solution heat treatment of aluminum alloy for lightweight automotive have been investigated. The test specimens, Al-6Si-2Cu alloys are prepared by gravity casting process. Solution heat treatments in this study are applied to improve of mechanical properties through a single-step or two-step solution heat treatment. For the microstructural characterization, inductively coupled plasma mass spectromerty (ICP-MS), optical microscope (OM) and scanning electron microscope (SEM) analyses are conducted in specimen. The X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analyses are also applied to identify the intermetallic phases with quantitative and qualitative analyses. Micro Vickers hardness and static tensile test are achieved. The microstructure of gravity casting specimen represents a typical dendrite structure having a secondary dendrite arm spacing (SDAS) of 37um. In addition to the Al matrix, a large amount of coarsen eutectic Si, Al2Cu intermetallic phases and Fe-rich phases are identified. After solution heat treatment, the mechanical properties of two-step solution heat treatment alloy show higher values than as-cast and single-step solution specimens. Consequentially, the two-step solution heat treatment could be used in automotive parts to improve mechanical properties.

Mechanical Properties of ZrO2–LaMgAl11O19 Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 455-458 ◽  
Author(s):  
Xin Min ◽  
Ming Hao Fang ◽  
Yan Gai Liu ◽  
Zhao Hui Huang ◽  
Feng Jiao Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Room Temperature ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Transformation Toughening ◽  
Flexure Strength ◽  
Phase Transformation Toughening ◽  
Physical And Chemical ◽  
And Chemical Properties

ZrO2 ceramics have been widely used to many fields with its excellent physical and chemical properties, but the mechanical properties of YSZ ceramics, especially the fracture toughness, decline caused by the failure of the phase transformation toughening at high temperature. In this investigation, plate-like LaMgAl11O19 toughened ZrO2 ceramics were prepared by pressureless sintering at 1550 °C for 3h in air . The bulk density of the sintered samples are between 5.5 to 6.0 g/cm3, and the relative density are above 93%. The mechanical properties of the ZrO2-LaMgAl11O19 ceramics were studied systematically at room temperature. The flexure strength and fracture toughness of ZrO2-LaMgAl11O19 ceramic are 811.8 MPa and 13.9 MPa•m½ with the LMA addition of 2wt%.

Effect of Gravity/ Vibration/ Centrifugal Process on Mechanical Properties of an Al-Si Alloy

2008 ◽  
Vol 587-588 ◽  
pp. 395-399
Author(s):  
G. Chirita ◽  
I. Stefanescu ◽  
Delfim Soares ◽  
F.S. Silva
Keyword(s):  
Mechanical Properties ◽  
Rupture Strength ◽  
Centrifugal Casting ◽  
Young Modulus ◽  
Casting Process ◽  
Centrifugal Effect ◽  
Gravity Casting ◽  
Casting Technique ◽  
Vibration Effect ◽  
Centrifugal Process

On this paper, a study that evaluates the influence of some variables on the mechanical properties of the vertical centrifugal casting is made. It is emphasized the fact that the centrifugal effect from vertical centrifugal casting brings special features on mechanical properties. It has been observed that the centrifugal effect may substantially increase, in some alloys, the rupture strength, rupture strain, and Young modulus, as compared to the gravity casting technique. When compared to gravity casting, the centrifugal casting process, besides the centrifugal force (pressure effect), always has an inherent associated vibration during the casting. In this study, as an attempt to isolate the vibration effect from the overall centrifugal effect, tests on castings obtained by vibrating gravity casting process are made. A comparison between castings obtained by centrifugal casting technique, vibrating casting technique and gravity casting technique is made in order to fully understand the features that allow the improvement on mechanical properties during the vertical centrifugal casting technique. An analysis of the most important effects, on both mechanical properties and on some metallurgical features is made.

scholarly journals An Experimental Study of Torsional Properties of Polyvinylchloride

2017 ◽  
Vol 2 (3) ◽  
pp. 273-278
Author(s):  
Sarkawt Rostam ◽  
Arazw Hamakarim ◽  
Avan Xalid ◽  
Pari Said ◽  
Kashab Muhammad
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Shear Modulus ◽  
Room Temperature ◽  
Testing Machine ◽  
Effect Of Temperature ◽  
Torsion Testing ◽  
Torsional Resistance ◽  
Applied Torque ◽  
Torsional Fracture

In this research, an experimental study has been performed to investigate the mechanical properties through torsion testing of polyvinylchloride (PVC) polymer specimens. For the purpose of the experimentation, specimens of PVC round bars have been prepared. Torsion testing machine apparatus of 200 Nm motor driven was used to evaluate the torsion properties of the tested bars. The apparatus provides four deformation speeds of 50°/min, 100°/min, 200°/min and 500 °/min. The tests conducted under different conditions in a room temperature and cooling of the samples and tested at different deformation speeds given by the torsion apparatus. Various tests produce the torsional moment- angle of rotation diagrams and thereafter both of torsional fracture resistance and shear modulus have been calculated. The results showed the effect of temperature change on the mechanical properties of PVC by making the material harder and can resist higher value of the applied torque where the range is from 2.9 N.m for the cooled sample to 2 N.m for the received samples tested at room temperature. Moreover the results showed an increase of shear modulus to 282 MPa for the cooled samples in compare to 140 MPa for as received samples. Finally the results provide a guideline for designers on how to use parts made of PVC in different applications where the range of both the maximum torque and failure torque with their mechanical properties of rigidity and torsional resistance were recorded.

Sign in / Sign up

Export Citation Format

Share Document