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.

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.

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 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.

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.

scholarly journals Effect of extreme cold temperatures on quasi-static indentation and impact behavior of woven carbon fiber epoxy composite sandwich panels with nomex honeycomb core

2021 ◽  
pp. 109963622199387
Author(s):  
Mathilde Jean-St-Laurent ◽  
Marie-Laure Dano ◽  
Marie-Josée Potvin
Keyword(s):  
Epoxy Composite ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
Cold Temperatures ◽  
Composite Sandwich Panels ◽  
Composite Sandwich ◽  
Static Indentation ◽  
Nomex Honeycomb ◽  
Extreme Cold ◽  
The Impact

The effect of extreme cold temperatures on the quasi-static indentation and the low velocity impact behavior of woven carbon/epoxy composite sandwich panels with Nomex honeycomb core was investigated. Impact tests were performed at room temperature, –70°C, and –150°C. Two sizes of hemispherical impactor were used combined to three different impactor masses. All the impact tests were performed at the same initial impact velocity. The effect of temperature on the impact behavior is investigated by studying the load history, load-displacement curves and transmitted energy as a function of time curves. Impact damage induced at various temperatures was studied using different non-destructive and destructive techniques. Globally, more damages are induced with impact temperature decreasing. The results also show that the effect of temperature on the impact behavior is function of the impactor size.

Variations in Fracture Toughness for Alloy 718 Given a Modified Heat Treatment

1990 ◽  
Vol 112 (1) ◽  
pp. 116-123 ◽  
Author(s):  
W. J. Mills ◽  
L. D. Blackburn
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Fracture Mechanisms ◽  
Alloy 718 ◽  
Percent Confidence Level ◽  
Heat Treated ◽  
Curve Method ◽  
Heat Treated Condition ◽  
The Impact ◽  
Product Forms

Heat-to-heat and product-form variations in the JIC fracture toughness for Alloy 718 were characterized at 24, 427, and 538°C using the multiple-specimen JR-curve method. Six different material heats along with three product forms from one of the heats were tested in the modified heat treated condition. This heat treatment was developed at Idaho National Engineering Laboratory to improve the impact toughness for Alloy 718 weldments, but it has also been found to enhance the fracture resistance for the base metal. Statistical analysis of test results revealed four distinguishable JIC levels with mean toughness levels ranging from 87 to 190 kJ/m2 at 24°C. At 538°C, JIC values were 15 to 20 percent lower than room temperature toughness levels. Minimum expected values of JIC (ranging from 72 kJ/m2 at 24°C to 48 kJ/m2 at 538°C) and dJR/da (27 MPa at 24 to 538°C) were established based on tolerance intervals bracketing 90 percent of the lowest JIC and dJR/da populations at a 95 percent confidence level. Metallographic and fractographic examinations were performed to relate key microstructural features and operative fracture mechanisms to macroscopic properties.

Effect of Temperature and Moisture on the Impact Behavior of Graphite/Epoxy Composites: Part II—Impact Damage

1995 ◽  
Vol 17 (1) ◽  
pp. 11 ◽  
Author(s):  
WS Johnson ◽  
JE Masters ◽  
ML Karasek ◽  
LH Strait ◽  
MF Amateau ◽  
...  
Keyword(s):  
Impact Damage ◽  
Epoxy Composites ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
The Impact

scholarly journals Cyclic Relaxation, Impact Properties and Fracture Toughness of Carbon and Glass Fiber Reinforced Composite Laminates

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7412
Author(s):  
Mohammed Y. Abdellah ◽  
Mohamed K. Hassan ◽  
Ahmed F. Mohamed ◽  
Ahmed H. Backar
Keyword(s):  
Fracture Toughness ◽  
Glass Fiber ◽  
Composite Laminates ◽  
Fiber Composite ◽  
Impact Behavior ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced ◽  
Glass Fiber Composite ◽  
Cyclic Relaxation ◽  
The Impact

In this paper, the mechanical properties of fiber-reinforced epoxy laminates are experimentally tested. The relaxation behavior of carbon and glass fiber composite laminates is investigated at room temperature. In addition, the impact strength under drop-weight loading is measured. The hand lay-up technique is used to fabricate composite laminates with woven 8-ply carbon and glass fiber reinforced epoxy. Tensile tests, cyclic relaxation tests and drop weight impacts are carried out on the carbon and glass fiber-reinforced epoxy laminates. The surface release energy GIC and the related fracture toughness KIC are important characteristic properties and are therefore measured experimentally using a standard test on centre-cracked specimens. The results show that carbon fiber-reinforced epoxy laminates with high tensile strength give high cyclic relaxation performance, better than the specimens with glass fiber composite laminates. This is due to the higher strength and stiffness of carbon fiber-reinforced epoxy with 600 MPa compared to glass fiber-reinforced epoxy with 200 MPa. While glass fibers show better impact behavior than carbon fibers at impact energies between 1.9 and 2.7 J, this is due to the large amount of epoxy resin in the case of glass fiber composite laminates, while the impact behavior is different at impact energies between 2.7 and 3.4 J. The fracture toughness KIC is measured to be 192 and 31 MPa √m and the surface energy GIC is measured to be 540.6 and 31.1 kJ/m2 for carbon and glass fiber-reinforced epoxy laminates, respectively.

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