Mechanical Properties of 91% Tungsten Alloy

2007 ◽  
Vol 345-346 ◽  
pp. 1625-1628 ◽  
Author(s):  
Wei Dong Song ◽  
Hai Yan Liu ◽  
Jian Guo Ning
Keyword(s):  
Crack Initiation ◽  
Tensile Tests ◽  
Tungsten Alloy ◽  
Test Results ◽  
Bending Tests ◽  
Three Point Bending ◽  
Grain Sizes ◽  
Initiation And Propagation ◽  
Fracture Behaviors ◽  
The Matrix

The tensile tests and the three-point bending tests have been conducted to investigate the crack initiation and propagation and the fracture behavior of 91W-6.3Ni-2.7Fe with three kinds grain sizes of 1~3μm, 10~15μm and 30~40μm. SEM was introduced to analyze the grain sizes, the micro-defects, the deformations and the fracture behaviors of tungsten alloys. The test results show that under the same loading conditions, the crack initiation and the crack propagation are not only related to grain size, but also related to the contiguity of tungsten grains and the interface between the tungsten grains and the matrix.

Influence of Striker Shape on the Crack Initiation and Propagation on Laterally Impacted Thin Aluminium Plates

2013 ◽  
Author(s):  
Bin Liu ◽  
Richard Villavicencio ◽  
C. Guedes Soares
Keyword(s):  
Crack Initiation ◽  
Failure Modes ◽  
Testing Machine ◽  
Tensile Tests ◽  
Impact Testing ◽  
Small Scale ◽  
Crack Initiation And Propagation ◽  
Initiation And Propagation ◽  
The Matrix ◽  
Force Displacement

Experimental and numerical results of drop weight impact tests are presented, examining the plastic response and the crack initiation and propagation of small-scale clamped rectangular aluminium plates laterally impacted by different indenter shapes. The experiments are conducted using a fully instrumented impact testing machine. The shape of the deformation of the specimens and the process of initiation and propagation of the material fracture is presented. The obtained force-displacement responses show a good agreement with the simulations performed by the LS-DYNA finite element solver. The strain hardening of the material is defined using experimental data of quasi-static tensile tests and the critical failure strain is evaluated measuring the thickness and the width at fracture of the tensile test pieces. The results show that the absorbed energy to perforate the specimens is highly sensitive to the shape of the striker. Thus, the crack propagation for each striker type is analysed in terms of the force-displacement response. The failure modes are described by the matrix of the infinitesimal strain tensors and the shape of the deformation of the failing elements.

scholarly journals Evaluation of the Feasibility of the Use of Bamboo as Potential Reinforcement in Concrete Beams

2019 ◽  
Vol 3 (1) ◽  
pp. 9-17
Author(s):  
S. O. Osuji ◽  
N. Kayode-Ojo
Keyword(s):  
Concrete Beams ◽  
Tensile Tests ◽  
Absorption Test ◽  
Test Results ◽  
Bending Tests ◽  
Three Point Bending ◽  
Steel Reinforced Concrete ◽  
Concrete Members ◽  
Load Carrying ◽  
Bamboo Reinforcement

This study presents the evaluation of the feasibility of using bamboo as a potential reinforcement in concrete beams. To achieve this, absorption test, tensile tests on the bamboo; compressive test on concrete cubes were conducted. Three-point bending tests on concrete beams reinforced with bamboo were performed to identify their behaviour compared to steel reinforced concrete members. The result for the absorption test indicated that water absorption of bamboo is quite high. The bamboo absorbed about 25% of water of its saturated weight in just 24 hrs and increased number of nodes brought about increased absorption of water. It also showed that the bamboo from the top part of the culm absorbed more water than those from the bottom of the culm, with an increase of about 9%. For the tensile tests all the bamboo specimens showed brittle failure at node, making the node the most critical section for failure under tensile stresses, which was also verified in the beam tests. The yield stress was 56.80 N/mm2. In general, the test results indicated that bamboo reinforcement enhanced the load carrying capacity by approximately 200%.

scholarly journals Study of the Microstructure and Crack Evolution Behavior of Al-5Fe-1.5Er Alloy

2018 ◽  
Author(s):  
Ming Li ◽  
Zhiming Shi ◽  
Xiufeng Wu ◽  
Huhe Wang ◽  
Yubao Liu
Keyword(s):  
Crack Initiation ◽  
Tensile Tests ◽  
Eutectic Structure ◽  
Interface Structure ◽  
Crack Evolution ◽  
Binding Ability ◽  
Initiation And Propagation ◽  
The Matrix ◽  
Evolution Behavior

The microstructure of Al-5Fe-1.5Er alloy was characterized and analyzed by using XRD, SEM, TEM and EDS. The effect of microstructure on the behavior of crack initiation and propagation was investigated by in situ tensile testing. Results show that the microstructure consists of α-Al matrix, Al3Fe, Al4Er, eutectic phase Al3Fe + Al4Er, while the 1.5 wt.% Er was added in Al-5Fe alloy. The twin structure of the Al3Fe phase was observed, and the twin plane is {001}. Moreover, a continuous concave and convex interface structure of the Al4Er has been found. Al3Fe is in the form of a sheet with a clear gap inside.In situ tensile tests of the alloy at room temperature show that the crack initiation occured mainly in the Al3Fe phase, and that the crack propagation modes include intergranular and transgranular expansion. Crack transgranular expansion is due to the strong binding ability between Al4Er phases and surrounding organization, and the continuous concave and convex interface structure of the Al4Er provides a significant meshing effect on the matrix and eutectic structure.

Crack Initiation Process for Semi-Circular Notched Plate in Fatigue Test at Elevated Temperature

2008 ◽  
Author(s):  
Bopit Bubphachot ◽  
Osamu Watanabe ◽  
Nobuchika Kawasaki ◽  
Naoto Kasahara
Keyword(s):  
Elevated Temperature ◽  
Crack Initiation ◽  
Fatigue Test ◽  
Video Camera ◽  
Test Results ◽  
Structural Components ◽  
Crack Initiation And Propagation ◽  
Propagation Process ◽  
Initiation Process ◽  
Initiation And Propagation

Crack initiation and propagation process of fatigue test in semi-circular notched plates at elevated temperature were observed by the CCD video camera. Test specimens are made of SUS304 stainless steel, and temperature is kept to be 550°C, and geometry of semi-circular notched plate specimens are changed by diameter size of the circular hole. Photographs in all cycles were recorded to investigate crack initiation process in structural components having stress concentration and obtain number of cycle of crack initiation (Nc). The test results were compared with predictions by Stress Redistribution Locus (SRL) method and Neuber’s rule’s method.

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.

scholarly journals Study of the Microstructure and Crack Evolution Behavior of Al-5Fe-1.5Er Alloy

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 172 ◽  
Author(s):  
Ming Li ◽  
Zhiming Shi ◽  
Xiufeng Wu ◽  
Huhe Wang ◽  
Yubao Liu
Keyword(s):  
Electron Microscopy ◽  
Crack Initiation ◽  
Tensile Tests ◽  
Eutectic Structure ◽  
Interface Structure ◽  
X Ray ◽  
Transmission Electron ◽  
The Matrix ◽  
Evolution Behavior

In this work, the microstructure of Al-5Fe-1.5Er alloy was characterized and analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) techniques. The effect of microstructure on the behavior of crack initiation and propagation was investigated using in situ tensile testing. The results showed that when 1.5 wt.% Er was added in the Al-5Fe alloy, the microstructure consisted of α-Al matrix, Al3Fe, Al4Er, and Al3Fe + Al4Er eutectic phases. The twin structure of Al3Fe phase was observed, and the twin plane was {001}. Moreover, a continuous concave and convex interface structure of Al4Er was observed. Furthermore, Al3Fe was in the form of a sheet with a clear gap inside. In situ tensile tests of the alloy at room temperature showed that the crack initiation mainly occurred in the Al3Fe phase, and that the crack propagation modes included intergranular and trans-granular expansions. The crack trans-granular expansion was due to the strong binding between Al4Er phases and surrounding organization, whereas the continuous concave and convex interface structure of Al4Er provided a significant meshing effect on the matrix and the eutectic structure.

Creep Rupture Bending Test of 20 Percent Cold-Prestrained Ni-Fe-Cr Alloy Straight Tubes at 1100 F(593 C)

1981 ◽  
Vol 103 (4) ◽  
pp. 337-344 ◽  
Author(s):  
H. H. Woo ◽  
R. H. Ryder ◽  
K. H. Holko ◽  
R. F. Stetson
Keyword(s):  
Crack Initiation ◽  
Creep Rupture ◽  
Bending Test ◽  
Strain History ◽  
Test Results ◽  
Local Material ◽  
Initiation And Propagation ◽  
Nonuniform Stress Field ◽  
Point Bend ◽  
Four Point Bend Test

A four-point bend test was performed on 20 percent cold-prestrained Ni-Fe-Cr alloy tubes at 1100 F (593 C) to verify that creep rupture damage can be used to predict failure in a nonuniform stress field. Deflection control and acoustic emission techniques were used to detect crack initiation, strain gages were employed to record the strain history in the specimen, and a scanning electron microscrope was utilized to check crack initiation and propagation. Stress analyses were made using simplified and finite element methods. Comparison of test results and analyses concluded that creep rupture damage can be used to predict local material failure for structural components under multiaxial nonuniform loading conditions.

Fracture properties of self-compacting fiber-reinforced concrete

2020 ◽  
Vol 11 (4) ◽  
pp. 112
Author(s):  
Mariam Farouk Ghazy ◽  
Metwally Abd Allah Abd Elaty ◽  
Omar Daboun
Keyword(s):  
Reinforced Concrete ◽  
Fiber Reinforced Concrete ◽  
Test Results ◽  
Fiber Reinforced ◽  
Bending Tests ◽  
Fracture Properties ◽  
Three Point Bending ◽  
Slump Flow ◽  
Hardened Properties ◽  
Application Fields

Self-compacting concrete (SCC) is an innovative concrete that does not necessitate vibration for placing and compaction. Nineteen concrete mixes were investigated including a control mix without fibers as well as eighteen SCC with fibers (SCFRC) mixes. Three types of fibers (polypropylene, glass and steel) were used. Slump flow, L-box, V-funnel as well as column segregation tests were conducted to assess the fresh properties. Whereas, compressive, splitting tensile and flexural strengths were measured to assess the hardened properties of SCFRC. Three point bending tests were performed for the purpose of assessing the fracture properties of SCFRC. Test results showed that the inclusion of fibers to produce SCFRC mixtures remarkably enhanced the fracture properties including fracture energy (Gf) and fracture toughness (K1c). Inclusion of steel fibers with 2% volume fractions showed an improvement with 26.9 times for Gf over the control mix. Whereas, 104% increase in K1c was recorded for the same mix over the mix without fibers. Adding fibers to SCC to produce self-compacting fiber reinforced concrete (SCFRC) will expand its advantages. However, the application fields still need to understand the properties of SCFRC.

Numerical Simulation of Granite Sawing by Discrete Element Method

2009 ◽  
Vol 16-19 ◽  
pp. 1283-1288
Author(s):  
Yong Ye ◽  
Yuan Li ◽  
Xi Peng Xu
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Point Of View ◽  
Bending Tests ◽  
Three Point Bending ◽  
Deformation Stage ◽  
Initiation And Propagation ◽  
Discontinuous Deformation ◽  
Sawing Process ◽  
Element Method

Granite is a kind of typical discrete material, which experiences from continuous deformation stage, discontinuous deformation stage to fracture stage under sawing forces. Using discrete element method (DEM) to study the process of sawing granite will help us to understand the removal mechanism of granite from the microscopic point of view. In this paper, numerical uniaxial compression and three-point bending tests were conducted to determine the microscopic parameters of the granite specimen firstly, and then simulation was performed for sawing of the specimen. The sawing process, deformation characteristics of granite and the effect of initiation and propagation of cracks on fracture process of granite were investigated. The emphasis was laid on analyzing the variation of sawing forces under different sawing parameters. The simulation results agree well with that of experiments, indicating that DEM can reflect the external macroscopic change of granite by changing the internal microscopic structure. The conclusions in this study would be useful to the modeling of sawing processes and engineering applications.

Springback Behavior of an Invar Sheet and Its Perforated Form

2006 ◽  
Vol 505-507 ◽  
pp. 781-786
Author(s):  
Yi Che Lee ◽  
Fuh Kuo Chen
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Test Results ◽  
Bending Tests ◽  
Predicted Values ◽  
Springback Behavior ◽  
Good Agreement

The springback behavior of an invar sheet and its perforated form were examined in the present study. The mechanical properties for invar sheet and perforated invar-sheet at elevated temperatures were first obtained from tensile tests. The test results suggest that both invar sheet and perforated invar-sheet have favorable formability at temperature higher than 200oC. An analytical model was also established to predict the springback of the invar sheet and its perforated form under bending conditions at various elevated temperatures. In order to verify the predicted results, the V-bending tests were conducted for the invar sheet at various temperatures ranging from room temperature to 300. The experimental data indicate that the springback decreases with the rise in temperature for both invar sheet and perforated invar-sheet. The good agreement between the experimental data and the predicted values confirms the validity of the proposed theoretical model as well.

Sign in / Sign up

Export Citation Format

Share Document