scholarly journals Effect of Temperature-Force Factors and Concentrator Shape on Impact Fracture Mechanisms of 17Mn1Si Steel

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
S. V. Panin ◽  
P. O. Maruschak ◽  
I. V. Vlasov ◽  
D. D. Moiseenko ◽  
F. Berto ◽  
...  
Keyword(s):  
Decisive Role ◽  
Testing Temperature ◽  
Impact Fracture ◽  
Effect Of Temperature ◽  
Fracture Mechanisms ◽  
Fracture Characterization ◽  
Different Temperatures ◽  
Temperature Force ◽  
The Impact

The influence of the notch shape on the impact fracture of 17Mn1Si steel is investigated at different temperatures with the focus placed on the low-temperature behavior. An approach towards fracture characterization has been suggested based on the description of elastic-plastic deformation of impact loaded specimens on the stage of crack initiation and growth at ambient and lower temperatures. The analysis of the impact loading diagrams and fracture energy values for the pipe steel 17Mn1Si revealed the fracture mechanisms depending on the notch shape. It was found that the testing temperature reduction played a decisive role in plastic strain localization followed by dynamic fracture of the specimens with differently shaped notches. A classification of fracture macro- and microscopic mechanisms for differently notched specimens tested at different temperatures was proposed which enabled a self-consistent interpretation of impact test results.

Effect of Temperature on Impact Properties of ZA27 Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 75-80 ◽  
Author(s):  
Li Ping Zhong ◽  
Jia Yong Si ◽  
Zi Qiao Zheng
Keyword(s):  
Impact Toughness ◽  
Fracture Surface ◽  
Impact Energy ◽  
Impact Testing ◽  
Impact Fracture ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
Za27 Alloy ◽  
Different Temperatures ◽  
The Impact

The impact toughness of ZA27 alloy at different temperatures is investigated by pendulum impact testing. In addition, the morphology of impact fracture surface observed by SEM. The results indicate that impact energy of ZA27 alloy is reduced with the temperature rising when the temperature is lower than 100°C. At 100°C to 200°C, impact energy increase as the temperature rising. And when the temperature reaches to 250°C, impact energy suddenly descend. Impact energy is the highest and reaches to 72.768J at 20°C. At impact fracture surface, it is mostly tear ridges and dimples. The higher the impact energy is, the more obvious the characteristic of tear ridges is. Furthermore, dimples are small and distribute more uniformly. Lower the impact energy, the less distinct of tear ridges. Dimples are larger and deeper, their distribution are not uniform. Impact behavior of material could be evaluated by the width of impact curve. The wider the peak of impact curve, the higher the impact toughness. But impact toughness is worse while peak is narrow.

Fracture Toughness and Fracture Mechanisms of PBT/PC/IM Blend

1992 ◽  
Vol 274 ◽  
Author(s):  
Jingshen Wu ◽  
Yiu-Wing Mai ◽  
Brian Cotterell
Keyword(s):  
Fracture Toughness ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
Fracture Mechanisms ◽  
Polybutylene Terephthalate ◽  
Different Temperatures ◽  
Work Concept ◽  
The Impact ◽  
Specific Fracture ◽  
Fracture Work

ABSTRACTStatic and impact fracture toughness of a Polybutylene terephthalate (PBT)/Polycarbonate (PC)/Impact modifier (IM) blend was studied at different temperatures. The experimental results were interpreted by the specific fracture work concept and J-integral analysis. It is found that the specific fracture work concept characterizes the impact behavior of the blend very well. In the static fracture tests the specific fracture work gives the crack initiation resistance of the blend which is consistent with the JIC value obtained. The effect of temperature was also examined and the fracture mechanisms were investigated via TEM and SEM. Extensive cavitation of the impact modifiers and plastic flow of matrix in the vicinity of the crack tip is believed to be the major toughening process of the enhanced fracture toughness.

scholarly journals Effect of temperature, CO2 and O2 on motility and mobility of Anisakidae larvae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aiyan Guan ◽  
Inge Van Damme ◽  
Frank Devlieghere ◽  
Sarah Gabriël
Keyword(s):  
Enzymatic Digestion ◽  
Infected Fish ◽  
Effect Of Temperature ◽  
Video Recordings ◽  
Different Temperatures ◽  
Semi Solid ◽  
Zoonotic Parasites ◽  
The Impact ◽  
Phosphate Buffered Saline

AbstractAnisakidae, marine nematodes, are underrecognized fish-borne zoonotic parasites. Studies on factors that could trigger parasites to actively migrate out of the fish are very limited. The objective of this study was to assess the impact of different environmental conditions (temperature, CO2 and O2) on larval motility (in situ movement) and mobility (migration) in vitro. Larvae were collected by candling or enzymatic digestion from infected fish, identified morphologically and confirmed molecularly. Individual larvae were transferred to a semi-solid Phosphate Buffered Saline agar, and subjected to different temperatures (6 ℃, 12 ℃, 22 ℃, 37 ℃) at air conditions. Moreover, different combinations of CO2 and O2 with N2 as filler were tested, at both 6 °C and 12 °C. Video recordings of larvae were translated into scores for larval motility and mobility. Results showed that temperature had significant influence on larval movements, with the highest motility and mobility observed at 22 ℃ for Anisakis spp. larvae and 37 ℃ for Pseudoterranova spp. larvae. During the first 10 min, the median migration of Anisakis spp. larvae was 10 cm at 22 ℃, and the median migration of Pseudoterranova spp. larvae was 3 cm at 37 ℃. Larval mobility was not significantly different under the different CO2 or O2 conditions at 6 °C and 12 ℃. It was concluded that temperature significantly facilitated larval movement with the optimum temperature being different for Anisakis spp. and Pseudoterranova spp., while CO2 and O2 did not on the short term. This should be further validated in parasite-infected/spiked fish fillets.

Effect of temperature on the impact behavior of PVC/ASA binary blends with various ASA terpolymer contents

2019 ◽  
Vol 39 (5) ◽  
pp. 407-414 ◽  
Author(s):  
Xueqiang Zhang ◽  
Jun Zhang
Keyword(s):  
Shell Structure ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
Core Shell ◽  
Binary Blends ◽  
Heat Distortion Temperature ◽  
Different Temperatures ◽  
Hard Shell ◽  
Core Shell Structure ◽  
The Impact

AbstractAcrylonitrile-styrene-acrylic (ASA) terpolymer has a typical core-shell structure with poly(butyl acrylate) (PBA) as the soft core and styrene-acrylonitrile (SAN) copolymer as the hard shell. The impact behavior of poly(vinyl chloride) (PVC)/ASA binary blends with various ASA terpolymer contents was systematically investigated at three different temperatures (23°C, 0°C, and –30°C). With the addition of 30 phr ASA terpolymer, the impact strength of the blends increased by almost 45 times at 23°C and 29 times at 0°C compared with the neat PVC, respectively. Herein, ASA terpolymer particles were related to each other to form a percolation group and the stress field around the ASA particles was connected with each other, thereby more effectively served as the stress concentrators, exhibiting the highest toughening efficiency. In addition, the significantly improved toughness could also be attributed to the special core-shell structure of ASA terpolymer, as well as, a good miscibility between the PVC matrix and the SAN shell of the ASA terpolymer. However, the decreasing temperature limited the flexibility of the PBA chain, resulting in the insignificant role of ASA terpolymer in toughening PVC at –30°C. Moreover, the improvement in the toughness of the blends did not sacrifice its heat distortion temperature.

scholarly journals Investigation of the impact of a broad range of temperatures on the physiological and transcriptional profiles of Zymomonas mobilis ZM4 for high-temperature-tolerant recombinant strain development

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Runxia Li ◽  
Wei Shen ◽  
Yongfu Yang ◽  
Jun Du ◽  
Mian Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Ethanol Production ◽  
Heat Tolerance ◽  
Zymomonas Mobilis ◽  
Glucose Utilization ◽  
Effect Of Temperature ◽  
Rna Seq ◽  
Transcriptional Profiles ◽  
Different Temperatures ◽  
The Impact

AbstractThe model ethanologenic bacterium Zymomonas mobilis has many advantages for diverse biochemical production. Although the impact of temperature especially high temperature on the growth and ethanol production of Z. mobilis has been reported, the transcriptional profiles of Z. mobilis grown at different temperatures have not been systematically investigated. In this study, Z. mobilis wild-type strain ZM4 was used to study the effect of a broad range of temperatures of 24, 30, 36, 40, and 45 °C on cell growth and morphology, glucose utilization and ethanol production, as well as the corresponding global gene expression profiles using RNA-Seq-based transcriptomics. In addition, a recombinant Z. mobilis strain expressing reporter gene EGFP (ZM4_EGFP) was constructed to study the effect of temperature on heterologous protein expression at different temperatures. Our result demonstrated that the effect of temperature on the growth and morphology of ZM4 and ZM4_EGFP were similar. The biomass of these two strains decreased along with the temperature increase, and an optimal temperature range is needed for efficient glucose utilization and ethanol production. Temperatures lower or higher than normal temperature investigated in this work was not favorable for the glucose utilization and ethanol production as well as the expression of exogenous protein EGFP based on the results of flow cytometry and Western blot. Temperature also affected the transcriptional profiles of Z. mobilis especially under high temperature. Compared with ZM4 cultured at 30 °C, 478 genes were up-regulated and 481 genes were down-regulated at 45 °C. The number of differentially expressed genes of ZM4 cultured at other temperatures (24, 36 or 40 °C) was relatively small though compared with those at 30 °C. Since temperature usually increases during the fermentation process, and heat tolerance is one of the important robustness traits of industrial strains, candidate genes related to heat resistance based on our RNA-Seq result and literature report were then selected for genetics study using the strategies of plasmid overexpression of candidate gene or replacement of the native promoter of candidate gene by an inducible Ptet promoter. The genetics studies indicated that ZMO0236, ZMO1335, ZMO0994, operon groESL, and cspL, which encodes Mrp family chromosome partitioning ATPase, flavoprotein WrbA, an uncharacterized protein, chaperonin Cpn10 and GroEL, and an exogenous cold shock protein, respectively, were associated with heat tolerance, and recombinant strains over-expressing these genes can improve their heat tolerance. Our work thus not only explored the effects of temperature on the expression of exogenous gene EGFP and endogenous genes, but also selected and confirmed several genes associated with heat tolerance in Z. mobilis, which provided a guidance on identifying candidate genes associated with phenotypic improvement through systems biology strategy and genetics studies for other microorganisms.

Effect of temperature on the impact fracture toughness of polymers

Polymer ◽  
1975 ◽  
Vol 16 (12) ◽  
pp. 915-920 ◽  
Author(s):  
E. Plati ◽  
J.G. Williams
Keyword(s):  
Fracture Toughness ◽  
Impact Fracture ◽  
Effect Of Temperature ◽  
The Impact

Impact Properties of TiC/Fe at Elevated Temperatures

2010 ◽  
Vol 434-435 ◽  
pp. 113-115
Author(s):  
Yan Rong Bao ◽  
Bin Li ◽  
Zong De Liu ◽  
Zhi Jian Bao
Keyword(s):  
Fracture Surface ◽  
Impact Test ◽  
Elevated Temperatures ◽  
Impact Fracture ◽  
X Ray Diffraction ◽  
Impact Properties ◽  
X Ray ◽  
Before And After ◽  
Different Temperatures ◽  
The Impact

The impact properties of TiC-Fe composite at different temperatures prepared by SHS / PHIP technique were investigated by impact test which was conducted in air from 20°C to 100020°C. Morphology of the impact fracture surface was observed by scanning electron microscope (SEM) and phase composition before and after the impact test was analyzed with X-Ray Diffraction. The results indicate that the impact toughness of TiC-Fe composite increases significantly with the temperature increasing above 700°C, representing a minimum value at 700°C. The impact fracture of TiC-Fe composite at room temperature, 700°C, 900°C and 1000°C is mainly brittle, showing certain plasticity with morphology of dimples as the temperature increases above 700°C. A small amount of Fe2O3 exists in the fracture surface, indicating TiC-Fe composite is oxidized partially during the impact test at elevated temperatures.

Characterization of Impact Fracture Behavior of Biodegradable PLA/PCL Polymer Blend

2006 ◽  
Vol 326-328 ◽  
pp. 1569-1572 ◽  
Author(s):  
Tetsuo Takayama ◽  
Mitsugu Todo ◽  
Kazuo Arakawa
Keyword(s):  
Fracture Behavior ◽  
Impact Resistance ◽  
Impact Fracture ◽  
Fracture Mechanisms ◽  
Thermoplastic Polymer ◽  
Fracture Properties ◽  
Impact Fracture Behavior ◽  
The Impact ◽  
Scanning Electron

Attempts have been made to improve the impact resistance of biodegradable thermoplastic polymer, PLA. A ductile biodegradable polymer, PCL, has been used to improve such property of PLA by using blending technique. Details of the impact fracture properties and mechanisms of PLA/PCL blends, however, have not fully been understood yet. Recently, it was also found that LTI can improve the immiscibility between PLA and PCL. In this study, PLA/PCL and PLA/PCL/LTI blends were prepared, and their impact fracture toughness values were measuredto assess the effect of PCL content and LTI addition on the impact resistance. Fracture mechanisms of the polymer blends were also characterized by scanning electron microscopy.

Yield analysis of copolymers: effect of temperature, feed ratio and initiator concentration on the copolymerization

2015 ◽  
Vol 35 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Hemlata R. Wasnik ◽  
Deepali S. Kelkar ◽  
Vikrant Y. Ganvir
Keyword(s):  
Effect Of Temperature ◽  
Feed Ratio ◽  
Reactivity Ratios ◽  
Analysis Method ◽  
Initiator Concentration ◽  
Monomer Reactivity Ratios ◽  
Chemical Methods ◽  
Different Temperatures ◽  
The Impact ◽  
Percentage Conversion

Abstract Copolymerization of pyrrole and aniline was carried out using chemical methods. The synthesis was carried out at different temperatures for different proportions of the monomers. The monomer reactivity ratios for pyrrole and aniline were calculated as 5.2 and 0.19, respectively, by using the low conversion analysis method. In addition, the same was done for two different concentrations of the initiator. The graphs for percentage conversion were plotted for various combinations of temperature, feed ratio and initiator concentration. Thus, an effort was made to study the impact of various parameters on the process of copolymerization.

scholarly journals Temperature Effect on the Thermal Conductivity of Expanded Polystyrene Foamed Concrete: Experimental Investigation and Model Correction

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Jinyan Shi ◽  
Yuanchun Liu ◽  
Baoju Liu ◽  
Dan Han
Keyword(s):  
Thermal Conductivity ◽  
Volume Fraction ◽  
Expanded Polystyrene ◽  
Effect Of Temperature ◽  
Dry Density ◽  
Insulation Property ◽  
Different Temperatures ◽  
Foamed Concrete ◽  
Thermal Insulation Property ◽  
The Impact

In this research, ultralightweight expanded polystyrene foamed concrete (EFC) was made by the chemical foaming method, and its thermal insulation property was measured by the transient method at different environment temperatures (from −10 to 40°C). Then, the effect of temperature and EPS volume fraction on the thermal conductivity and dry density of EFC were observed. Ultimately, the Cheng–Vachon equation was modified by introducing the temperature parameter. The results indicated that EFC thermal conductivity decreases with increasing temperature. It was also demonstrated that the suitable volume of EPS particles can not only decrease the EFC thermal conductivity but also reduce the impact of temperature on the thermal conductivity. The thermal conductivity of EFC at different temperatures was accurately predicted in this study using the proposed model.

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