Mechanical Property and Microstructure of the Vitrified-Bonded Ti-Coated CBN Composites

2018 ◽  
Vol 12 (6) ◽  
pp. 862-867
Author(s):  
Xue Sun ◽  
Tianbiao Yu ◽  
Zixuan Wang ◽  
Zhelun Ma ◽  
Maoqiang Xu ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Sintering Temperature ◽  
Cubic Boron Nitride ◽  
Test Results ◽  
Oxidation Reactions ◽  
X Ray Diffraction ◽  
Bending Tests ◽  
Three Point Bending ◽  
Abrasive Surface ◽  
Composite Samples

This paper investigates the mechanical property and microstructures of vitrified-bonded Ti-coated cubic boron nitride (CBN) composites under different sintering conditions. Three-point bending tests of the sintered vitrified-bonded Ti-coated CBN composite samples were carried out, and the microstructure, phase composition, and energy spectrum of the sintered composite samples were analyzed using SEM and X-ray diffraction. The test results indicate that the mechanical properties of the vitrified-bonded Ti-coated CBN composites improve with the increased temperature, and then show a declining trend. It was found that the titanium layer has a protective effect on the CBN abrasive. During the course of sintering, as the temperature increases, titanium in the titanium-coated layer is not only present on the CBN abrasive surface but is also diffused into the glass phase. In addition, oxidation reactions occur, which become stronger with the higher sintering temperature. Thus, the sintering temperature of the vitrified-bonded Ti-coated CBN composites should not be too high. It is better to sinter them in a vacuum rather than in air. Ti-coated CBN grains are not suitable for a vitrified bond with low refractoriness.

Investigation of tensile and flexural behavior of biaxial and rib 1 × 1 weft-knitted composite using experimental tests and multi-scale finite element modeling

2019 ◽  
Vol 53 (23) ◽  
pp. 3201-3215 ◽  
Author(s):  
Reza Hessami ◽  
Aliasghar Alamdar Yazdi ◽  
Abbas Mazidi
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Experimental Results ◽  
Flexural Behavior ◽  
Bending Tests ◽  
Three Point Bending ◽  
Element Modeling ◽  
Multi Scale ◽  
Scale Modeling ◽  
Composite Samples

In this study, tensile and flexural behavior of biaxial and rib weft-knitted composite is obtained numerically and experimentally. Multi-scale finite element modeling is employed to simulate the tensile and flexural behavior of composite samples. In the finite element modeling, the geometry of a unit cell of each fabric is initially modeled in ABAQUS software, and then periodic boundary conditions were applied to a unit cell. The stiffness matrix for each structure was obtained by a python code via meso scale modeling and used as input data for the macro modeling. To validate the numerical model, two types of weft-knitted fabrics (rib 1 × 1 and biaxial fabrics) are produced by a flat weft knitting machine. Epoxy resin is used to construct composite by the vacuum injection process (VIP). After that, the tensile and three-point bending tests were applied to composite samples. The experimental results showed that tensile strength and tensile modulus of biaxial composites are greater than rib composites, in both wale and course directions. Moreover, in three-point bending test, biaxial composite showed more strength and more stiffness in comparison to rib composite. Finite element results were compared to experimental results in tensile and bending tests. The results showed that good agreement with experimental results in the linear section of tensile and flexural behavior of composites. Consequently, the current multi-scale modeling can be used to predict the stiffness matrix and mechanical behavior of complex composite structures such as knitted composites.

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.

Microstructure and Strength of Low Temperature Co-Fired Ceramic Substrates With Channels and Cavities

2008 ◽  
Author(s):  
Yang-Fei Zhang ◽  
Min Miao ◽  
Yu-Feng Jin ◽  
Shu-Lin Bai
Keyword(s):  
Flexural Strength ◽  
Theoretical Calculations ◽  
Aluminum Silicate ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Ceramic Substrates ◽  
Bending Tests ◽  
Three Point Bending ◽  
Internal Structures ◽  
Fea Simulation

The effect of embedded channels and cavities on the strength of LTCC substrates has been investigated by experiments, theoretical analysis and finite element analysis (FEA) simulation. The fracture behaviors characterized by flexural strength were measured by three-point bending tests and discussed according to the features of the microstructure, which was studied by Scanning Electron Microscope, Energy Spectrum Analysis and X-Ray Diffraction methods. The experimental results show that X and Y-axial channels have little effect on the flexural strength while Z-axial via-hole will greatly lower the strength due to the stress concentration. Two distinct components were observed: particles composed of synthetic corundum and matrix composed of corundum, silica, aluminum, and sodium calcium aluminum silicate. The FEA simulation gave similar results to the experiments and theoretical calculations and proved to be an effective method to predict possible condition of the fracture on substrates with complex internal structures.

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.

scholarly journals Characterization of CaTi0.9Fe0.1O3/La0.98Mg0.02NbO4 composite

Open Physics ◽  
2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Aleksandra Mielewczyk-Gryn ◽  
Tomasz Lendze ◽  
Katarzyna Gdula-Kasica ◽  
Piotr Jasinski ◽  
Andrzej Krupa ◽  
...  
Keyword(s):  
Sintering Temperature ◽  
Perovskite Phase ◽  
Pyrochlore Phase ◽  
Diffraction Method ◽  
Total Conductivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Interaction ◽  
Composite Samples

AbstractA composite of CaTi0.9Fe0.1O3 and electrolyte material, i.e. magnesium doped La0.98Mg0.02NbO4 was prepared and studied. The phase content and the sample microstructure was examined by an X-ray diffraction method and scanning electron microscopy. EDS measurements were done both for composite samples and the diffusion couple. The electrical properties were studied by four terminal DC method. The high-temperature interaction between the two components of the composite has been observed. It has been suggested that lanthanum diffused into the perovskite phase and substituted for calcium whereas calcium and niobium formed the Ca2Nb2O7 pyrochlore phase. At 1500°C very large crystallites of the pyrochlore were observed. Regardless of strong interaction between the composite components, its total conductivity was weakly dependent on the sintering temperature.

Study of high-pressure sintering behavior of cBN composites starting with cBN–Al mixtures

2008 ◽  
Vol 23 (9) ◽  
pp. 2366-2372 ◽  
Author(s):  
Yongjun Li ◽  
Sicheng Li ◽  
Ran Lv ◽  
Jiaqian Qin ◽  
Jian Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Sintering Temperature ◽  
Cubic Boron Nitride ◽  
Sintering Behavior ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Al Content ◽  
High Pressure Sintering

Cubic boron nitride (cBN) composites starting with cBN–Al mixtures were sintered on WC-16 wt% Co substrates under static high pressure of 5.0 GPa and at temperatures of 800–1400 °C for 30 min. Vickers hardness of the sintered samples increased with increasing cBN content, and the highest hardness of 32.7 GPa was achieved for the cBN–5 wt% Al specimens sintered at 1400 °C. The reactions between cBN and Al started to occur at about 900 °C, and the reaction products strongly depended on the Al content, sintering temperature, and Co diffusion from the substrates according to the x-ray diffraction (XRD) observations. The high pressure and high temperature in situ resistance measurement indicated that the reactions between cBN and Al could be completed in about 90 s when the temperature was higher than ∼1200 °C at high pressure. The cBN composite sintered at 1200 °C from a cBN–15 wt% Al mixture showed the best cutting performance.

FRICTION STIR PROCESSING OF SKD61 TOOL STEEL

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1116-1121 ◽  
Author(s):  
YINGCHUN CHEN ◽  
KAZUHIRO NAKATA
Keyword(s):  
Mechanical Property ◽  
Tool Steel ◽  
Cubic Boron Nitride ◽  
Base Material ◽  
Wear Test ◽  
Hardness Test ◽  
Test Results ◽  
Friction Stir ◽  
Polycrystalline Cubic Boron Nitride ◽  
Observation Results

In this study, SKD61 tool steel was friction stir processed (FSP) using a polycrystalline cubic boron nitride (PCBN) tool. Microstructure evolution and mechanical property in FSP zone were investigated. Microstructural observation results showed that the microstructures in FSP zone surface were fine grains in the range of 1 - 4 μm due to large plastic deformation during FSP. Micro-hardness test results showed that the average hardness value in FSP zone was 773 HV, 3.7 times the hardness in base metal (210 HV). The wear test results showed that FSP surface showed a significantly lower wear rate than that of the base material at all loads. The relation between microstructural evolution and mechanical property in FSP zone was discussed.

Sintering of Ti3SiC2 Ceramics by Hot Press from Commercial Powders

2015 ◽  
Vol 655 ◽  
pp. 68-71
Author(s):  
Yuan Yuan Zhu ◽  
Jin Jia ◽  
Ai Guo Zhou ◽  
Li Bo Wang ◽  
Qing Feng Zan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Sintering Temperature ◽  
Hot Press ◽  
X Ray Diffraction ◽  
X Ray ◽  
Three Point Bending ◽  
Ternary Compounds ◽  
Scanning Electron

Layered ternary compounds Ti3SiC2combines attractive properties of both ceramics and metals, and has been suggested for potential engineering applications. Near-fully dense Ti3SiC2bulks were sintered from commercial Ti3SiC2powders by hot press at 1350°C-1600°C for 60-120min under Ar atmosphere in this paper. The phase compositions and morphology of the as-prepared samples were evaluated by X-Ray diffraction (XRD) and scanning electron microscopy (SEM). And the mechanical properties were measured by Three-Point bending method. It was found that the Ti3SiC2had only a little of decomposition at sintering temperature above 1350°C. And effects of sintering temperature and holding time on the morphology of the bulk Ti3SiC2are not obvious. Relative density of 98% and flexural strength of 480MPa were obtained for the Ti3SiC2samples sintered at 30MPa and 1400°C for 90min.

scholarly journals Processing and mechanical characterization of Al2O3/Ni and Al2O3/C0 composites by pressureless sintering of nanocomposite powders

2018 ◽  
Vol 12 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Yildiz Kafkaslioğlu ◽  
Hüseyin Yilmaz ◽  
Yahya Tür
Keyword(s):  
Fracture Toughness ◽  
Metallic Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Bending Tests ◽  
Three Point Bending ◽  
Green Strength ◽  
Nanocomposite Powders ◽  
Hardness Values

Al2O3/Ni and Al2O3/Co nanopowder mixtures (with 3 vol.% of metallic phase) were synthesized by heterogeneous precipitation method. In order to increase the green strength, polypropylene carbonate (PPC) was used as a binder while preparing green compacts. Uniaxially pressed powder mixtures were sintered at 1550?C for 2 h in a reducing atmosphere. The effects of Ni and Co nanophases on the microstructure and mechanical properties of Al2O3 ceramics were studied by X-ray diffraction, scanning electron microscopy, Vickers indentation technique and three-point bending tests. The metallic phase hindered the densification of alumina matrix, yet hardness values of Al2O3, Al2O3/Ni, and Al2O3/Co composites were comparable. Vickers fracture toughness results indicate that the composites have higher fracture toughness, but the characteristic flexural strength and Weibull modulus are higher for the pure Al2O3.

Modified Equation To Predict Leak/Rupture Criteria For Axially Through-Wall Notched X80 and X100 Linepipes Having a Higher Charpy Energy

2005 ◽  
Vol 128 (4) ◽  
pp. 572-580 ◽  
Author(s):  
Shinobu Kawaguchi ◽  
Naoto Hagiwara ◽  
Mitsuru Ohata ◽  
Masao Toyoda
Keyword(s):  
Fracture Toughness ◽  
Pipe Material ◽  
Test Results ◽  
Absorbed Energy ◽  
Bending Tests ◽  
Three Point Bending ◽  
Full Scale Tests ◽  
Hoop Stresses ◽  
The Relationship ◽  
Modified Equation

A method of predicting the leak/rupture criteria for API 5L X80 and X100 line pipes was evaluated based on the results of hydrostatic full-scale tests for X60, X65, X80, and X100 line pipes with an axially through-wall (TW) notch. The TW notch test results defined the leak/rupture criteria, that is, the relationship between the initial notch lengths and the maximum hoop stresses during the TW notch tests. The defined leak/rupture criteria were then compared to the prediction of the Charpy V-notch (CVN) absorbed energy-based equation, which has been proposed by Kiefner, Maxey et al. This comparison revealed that the CVN-based equation was not applicable to the pipes having both a CVN energy greater than 120 or 130 J and flow stress greater than the level of X65. In order to predict the leak/rupture criteria for these line pipes, the static absorbed energy for ductile cracking, (Cvs)i, was introduced as representing the fracture toughness of a pipe material. The (Cvs)i value was determined from the microscopic observation of the cut and polished Charpy V-notch specimens after static three-point bending tests. The CVN energy in the original CVN-based equation was replaced by an equivalent CVN energy, (Cv)eq, which was defined as follows: (Cv)eq=4.5(Cvs)i. The leak/rupture criteria for the X80 and X100 line pipes with higher CVN energies were reasonably predicted by the modified equation using the (Cvs)i value.

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