scholarly journals Investigation of Fatigue Behavior of ABS and PC-ABS Polymers at Different Temperatures

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1818
Author(s):  
Andrea Mura ◽  
Alessando Ricci ◽  
Giancarlo Canavese
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Working Condition ◽  
Fatigue Behavior ◽  
Polymeric Materials ◽  
Cyclic Loads ◽  
Structural Components ◽  
Working Temperature ◽  
Different Temperatures ◽  
Positive Effect

Plastics are widely used in structural components where cyclic loads may cause fatigue failure. In particular, in some applications such as in vehicles, the working temperature may change and therefore the strength of the polymeric materials. In this work, the fatigue behavior of two thermoplastic materials (ABS and PC-ABS) at different temperatures has been investigated. In particular, three temperatures have been considered representing the working condition at room temperature, at low temperature (winter conditions), and high temperature (summer conditions and/or components close to the engine). Results show that high temperature have big impact on fatigue performance, while low temperatures may also have a slight positive effect.

High Temperature Properties of CoFe/CoNi and Fe/CoNi Biphase Microwires

2015 ◽  
Vol 233-234 ◽  
pp. 265-268 ◽  
Author(s):  
Irene Iglesias ◽  
Rhimou El Kammouni ◽  
Kseniay Chichay ◽  
Manuel Vazquez ◽  
Valeria Rodionova
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Single Phase ◽  
Amorphous Structure ◽  
Magnetic Behaviour ◽  
Heating Process ◽  
Saturation Magnetostriction ◽  
Magnetostriction Constant ◽  
Different Temperatures ◽  
Drawing Technique

The objective of this work has been to analyze the high-temperature behavior of magnetically single-and biphase microwires because of its interest from fundamental and applications viewpoints. Two alloy compositions with amorphous structure covered by glass have been prepared as magnetically single phase microwires by quenching & drawing technique: CoFe-based with near zero saturation magnetostriction constant and Fe-based with positive saturation magnetostriction constant. The same wires were used as the core for magnetically biphase microwires. Second CoNi phase was deposited by electroplating. Magnitudes as saturation magnetization and hysteresis parameters are determined in the temperature range from room temperature up to 1200 K. We proceed to a comparative analysis of their magnetic behaviour at different temperatures as well as after cooling down to room temperature. Information on the Curie temperature of different phases and on the influence of heating process on the magnetic properties is thus derived.

Apparent Emissivity of Combustion Soot Aggregate Coating at High Temperature

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Tai Ran Fu ◽  
Ji Bin Tian ◽  
Hua Sheng Wang
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Room Temperature ◽  
Spectral Emissivity ◽  
Radiative Properties ◽  
Nickel Substrate ◽  
Soot Aggregate ◽  
Different Temperatures ◽  
Few Data ◽  
Total Hemispherical Emissivity

Soot aggregates frequently occur during combustion or pyrolysis of fuels. The radiative properties of soot aggregates at high temperature are important for understanding soot characteristics and evaluating heat transfer in combustion systems. However, few data for soot radiative properties at high temperature were available. This work experimentally investigated the apparent emissivity of the soot aggregate coating at high temperature using spectral and total hemispherical measurements. The soot aggregate coatings were formed on nickel substrates by a paraffin flame. The surface and inner morphology of the coatings were characterized by scanning electron microscope (SEM). The thickness of the coating was 30.16 μm so the contribution of the smooth nickel substrate to the apparent radiation from the coating could be neglected. The total hemispherical emissivity of the coating on the nickel substrate was measured using the steady-state calorimetric method at different temperatures. The spectral directional emissivity of the coating was measured for the wavelength of 0.38–16.0 μm at the room temperature. The measurements show that the total hemispherical emissivity decreases from 0.895 to 0.746 as the temperature increases from 438 K to 1052 K. The total hemispherical emissivity of the coating deposited on the nickel substrate is much larger than those of the nickel substrate and a nickel oxidization film. The measured spectral emissivity of the coating at the room temperature was used to theoretically calculate the total hemispherical emissivity at different temperatures by integration with respect to wavelength. The measured and calculated total hemispherical emissivities were similar, but their changes relative to temperature were completely opposite. This difference is due to the fact that the spectral emissivity of the coating is a function of temperature. The present results provide useful reference data for analyzing radiative heat transfer at high temperature of soot aggregates in combustion processes.

An Ultrasonic Non-Contact Handling Device from Quartz Glass for Middle and High Temperature Applications

2014 ◽  
Vol 1018 ◽  
pp. 31-38
Author(s):  
Edgars Locmelis
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Manufacturing Processes ◽  
Mechanical Contact ◽  
High Temperature Region ◽  
Handling Device ◽  
Design And Manufacturing ◽  
Different Temperatures ◽  
Small Change

Ultrasonic non-contact handling is used to manipulate surface sensitive and fragile workpieces, e.g. wafers and glass plates, without mechanical contact. While the technology is available forapplications at room temperature, some of the manufacturing processes of products mentioned aboverequire handling at elevated temperatures. To enable this technology for handling in thermal processesan ultrasonic system for increased working temperatures is required. In order to adapt the ultrasonicsystem to the limited working temperature of the actuator, the handling system has to be operated attwo different temperatures. Due to the small change of the Young's modulus over temperature, quartzglass was chosen as material for the components in the high temperature region. The paper presentsthe design and manufacturing of a novel ultrasonic system operated at 790 °C while the actuator iskept at room temperature.

On-Line Analysis of the Condensable Products of Biomass High Temperature Pyrolysis

2014 ◽  
Vol 521 ◽  
pp. 63-67 ◽  
Author(s):  
Lei Chen ◽  
Xiao Dong Zhang ◽  
Lai Zhi Sun ◽  
Xin Ping Xie ◽  
Bao Feng Zhao ◽  
...  
Keyword(s):  
High Temperature ◽  
Aromatic Hydrocarbon ◽  
Condensation Polymerization ◽  
Total Peak Area ◽  
Mass Ratios ◽  
Different Temperatures ◽  
On Line ◽  
Hydrocarbon Yield ◽  
Positive Effect ◽  
Line Analysis

High temperature pyrolysis of sawdust was achieved by using the analytical Py-GC/MS technique which allowed the on-line analysis of the pyrolysis product.The experiments at the different temperatures (700-1000°C) and the different mass ratios of CaO to sawdust (0%,10%,30%,50%) were carried out,respectively. At different temperatures, the distribution of condensable products considerably changed. At 700°C,the aromatic hydrocarbon yield were 0.9% of the total peak area. However, the aromatic hydrocarbon yield reached 59.4% of the total peak area at 1000°C, which might be due to the occurrence of the condensation polymerization at high temperature. CaO had a positive effect on decreasing the yield of the condensable products of sawdust pyrolysis, but did not remarkably change the distribution of the condensable products.

Temperature Dependence of 4H-SiC JBS and Schottky Diodes after High Temperature Treatment of Contact Metal

2005 ◽  
Vol 483-485 ◽  
pp. 945-948 ◽  
Author(s):  
R. Pérez ◽  
Narcis Mestres ◽  
Dominique Tournier ◽  
Xavier Jordá ◽  
Phillippe Godignon ◽  
...  
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Schottky Diodes ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Schottky Junction ◽  
Temperature Dependent ◽  
Working Temperature ◽  
Sic Wafer ◽  
Contact Metal

In this work we demonstrate performant characteristics of 1.2KV Schottky, Junction Barrier Schottky (JBS) and implanted PN diodes processed on the same 4H-SiC wafer. A bi-layer Ni/Ti scheme for the contact metallisation submitted to high temperature rapid thermal anneals is proved to form good ohmic contact on p+ implanted areas while maintaining good Schottky characteristics on lightly doped n-type regions. I-V characteristics have been evaluated from room temperature up to 560K. At room temperature, Schottky diodes have slightly better specific onresistance, but when working temperature is increased, the JBS diode exhibits better characteristics due to the temperature dependent activation of bipolar current injection from the p+ grid. From reverse measurements, the JBS diodes showed lower leakage current and higher breakdown voltages in comparison to that of the Schottky diodes in the whole range of temperatures.

scholarly journals Mechanical Properties of Glass-Based Geopolymers Affected by Activator and Curing Conditions under Optimal Aging Conditions

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 502
Author(s):  
Tai-An Chen
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Glass Powder ◽  
Weight Ratio ◽  
Polymeric Materials ◽  
Curing Temperature ◽  
Curing Conditions ◽  
Positive Effects ◽  
Aging Conditions ◽  
Optimal Values

Inorganic polymeric materials react slowly at room temperature and therefore, usually require high-temperature curing. This study determined the correlation between temperature and duration in high-temperature curing. The results revealed optimal values for each alkali equivalent of an activator (weight ratio of Na2O/glass powder), curing temperature, and curing duration. Increasing the curing duration and curing temperature had positive effects when the alkali equivalent was lower than the optimal percentage. However, over-curing resulted in the visible cracking of the specimens. Furthermore, despite being initially high, the compressive strength of specimens gradually diminished after standing in air. To ensure the durability of glass-based geopolymers, the curing temperature and duration should not exceed 70 °C, and 1 day, respectively.

Fatigue Behavior of Extruded Mg-Al-Ca-Mn Alloy with T6 Treatment at Elevated Temperature

2014 ◽  
Vol 627 ◽  
pp. 417-420 ◽  
Author(s):  
Yukio Miyashita ◽  
Hugo Inzunza ◽  
Adrian Elizondo ◽  
Yoshiyuki Murayama ◽  
Yuichi Otsuka ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Fatigue Strength ◽  
Fatigue Test ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Fatigue Property ◽  
Propagation Behavior ◽  
Replication Technique

Fatigue behavior of Mg-Al-Ca-Mn alloy with T6 treatment was studied at room temperature and 150°C by conduction rotating bending fatigue test. Fatigue strength at high temperature was lower than that at room temperature in the alloys with and without heat treatment. However, degradation of fatigue strength at high temperature in the T6 treated alloy was not significant compared to the as-extruded alloy. Fatigue crack initiation and propagation behavior was observed with replication technique by conducting interrupted fatigue test at room temperature and 150°C. Multiple cracking was significantly observed at 150°C in both as-received and T6 treated alloys. Change in grain size and randomization of crystal orientation due to the heat treatment could affect the fatigue property.

STRAIN RATE DEPENDENCE ON THE HIGH TEMPERATURE MECHANICAL BEHAVIOR OF THE NI-18SI-3.0NB-1.0CR-0.2B INTERMETALLIC ALLOY

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1040-1046 ◽  
Author(s):  
CHIH-CHIANG FU ◽  
JASON SHIAN-CHING JANG ◽  
I-SUI LEE ◽  
HUEI-SEN WANG
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Grain Boundaries ◽  
Room Temperature ◽  
Fracture Pattern ◽  
Strain Rates ◽  
Dispersion Phase ◽  
Air Atmosphere ◽  
Different Temperatures

The effect of strain rate and temperature on the mechanical behavior of the Ni -18 Si -3.0 Nb -1.0 Cr -0.2 B alloy was investigated by atmosphere-controlled tensile testing in vacuum and air atmosphere at different strain rates and different temperatures. The results reveal that the Ni -18 Si -3.0 Nb -1.0 Cr -0.2 B alloy exhibits ductile mechanical behavior (UTS > 1200 MPa, ε > 8%) at room temperature under different atmosphere conditions. In addition, both of the ultimate tensile strength and elongation exhibit quite insensitive response with respect to the loading strain rate when tests are held at temperatures below 973K. The elongation of the samples tested in vacuum and air for the Ni -18 Si -3 Nb -1 Cr -0.2 B alloy exhibits a significantly increase with temperature from 973K to 1073K. In addition, all fracture surfaces tested at 1073K in vacuum and air atmosphere presents a typical ductile fracture surface, a fully dimpled fracture pattern. The fact of increasing in elongation at high temperature (1073K) is suggested to be attributed by the dynamic recrystallization that occurs preferentially around the dispersion phase or grain boundaries and so as to enhance the ductility by reducing the stress concentration at or near grain boundaries.

Analysis on Residual Capacity of Steel after High Temperature

2013 ◽  
Vol 827 ◽  
pp. 322-327
Author(s):  
Xiu Ying Yang
Keyword(s):  
High Temperature ◽  
Carrying Capacity ◽  
Room Temperature ◽  
Numerical Models ◽  
Physical And Mechanical Properties ◽  
Steel Beams ◽  
Steel Material ◽  
Different Temperatures ◽  
Residual Capacity ◽  
Steel Properties

Steel material is very sensitive to temperature, the physical and mechanical properties at high temperature are distinct with those at room temperature. Taking steel beams as the research objects, based on EUROCODE3 for the steel properties at high temperature, this paper established numerical models and analyzed the carrying capacity of steel beams under different temperatures. According to the analysis, it is concluded that the higher the temperature, the lower the subsequent carrying capacity of the steel beam, and the formulas between them are defined by fitting the data.

Study on the Mechanical Property of Concrete Materials under High Temperature (Fire)

2012 ◽  
Vol 166-169 ◽  
pp. 3018-3022
Author(s):  
Man Li Ou ◽  
Wei Jun Cao ◽  
Long Min Jiang
Keyword(s):  
Mechanical Property ◽  
Compressive Strength ◽  
High Temperature ◽  
Room Temperature ◽  
Holding Time ◽  
Water Cooling ◽  
Different Temperatures ◽  
Concrete Materials

The performance of concrete materials under high temperature is more complex than that under room temperature. This paper, by analyzing the mechanical property of concrete materials under high temperature(fire), probes into the changing law of the concrete materials' compressive strength under different temperatures (16 °C-800 °C) and different static placing time and makes a comparison on the concrete materials' strength between natural cooling and water cooling; illustrates the relationships of concrete materials' compressive strength and temperature, holding time and cooling and other factors under high temperature(fire).

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