Influence of NbC-Addition on Mechanical Properties of WC-Co

2005 ◽  
Vol 498-499 ◽  
pp. 363-368 ◽  
Author(s):  
Wilson Acchar ◽  
Harim Revoredo de Macedo
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Niobium Carbide ◽  
Testing Machine ◽  
High Hardness ◽  
Inert Atmosphere ◽  
High Fracture Toughness ◽  
High Wear Resistance ◽  
High Fracture ◽  
First Results

Cemented carbides have been intensively used as cutting tool through their high hardness, high fracture toughness and high wear resistance. A considerable amount of works has been developed in order to improve the mechanical properties of alternate cemented carbide systems. This work has the purpose to reports the first results obtained to WC-Co reinforced with 5 wt.% NbC. The mixture of powders was hot-pressed at 1250 °C in a inert atmosphere. Hardness and fracture toughness were carried out in a Vickers hardness testing machine. The results have showed that the addition of niobium carbide improves the hardness of tungsten carbide and inhibits the WCgrain growth.

Deformation and Fracture Mechanics of Superior Nanocomposites

2020 ◽  
Vol 990 ◽  
pp. 244-249
Author(s):  
Lydia Anggraini
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
High Hardness ◽  
High Energy ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Fine Grained ◽  
Deformation And Fracture ◽  
Fine Microstructure

Lightweight ultra-fine grained (<1 μm size) SiC-ZrO2(3Y2O3) composites, with a combination of high hardness, high bending strength and high fracture toughness, were successfully prepared by high energy mechanical milling followed by heat treatment. The SiC-ZrO2(3Y2O3) composites exhibitied high hardness (1707 MPa), high bending strengh (as high as 1689 MPa) and high fracture toughness (up to approximately 12.6 MPa.m1/2). Such a combination of mechanical properties was attributed to the fine microstructure with a distinct feature consisting of almost continuous network of ZrO2(3Y2O3) phase around SiC grains, or we call harmonic microstructure. It has been demonstrated that a combination of these unique microstructural characteristics was very effective in supressing the initiation of cracks and governing the path of their subsequent growth during fracture, leading to excellent combination of mechanical properties.

Mechanical Properties of Al2O3-TiO2-SiC Nanocomposites for the Femoral Head of Hip Joint Replacement

2005 ◽  
Vol 486-487 ◽  
pp. 197-200 ◽  
Author(s):  
Santiago Visbal ◽  
Joaquín Lira-Olivares ◽  
Tohru Sekino ◽  
Koichi Niihara ◽  
Byung Kyu Moon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Femoral Head ◽  
Hip Joint ◽  
Joint Replacement ◽  
High Hardness ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Hip Joint Replacement ◽  
Mechanical And Tribological Properties

Microstructure and mechanical properties of Al2O3-TiO2-SiC nanocomposites were studied. To improve the mechanical and tribological properties of alumina, nano-sized TiO2 and SiC powders were dispersed. Spark Plasma Sintering (SPS) technique, at 1400°C, 50 MPa for 5 minutes, was applied for the densification of Al2O3-TiO2-SiC nanocomposites. Characterization of Al2O3- TiO2-SiC nanocomposites was carried out using Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM), X-ray diffractometer and EDX. Fracture toughness and Vickers hardness were estimated by indentation technique. These experimental results on mechanical properties of Al2O3-TiO2-SiC nanocomposites indicated that they can be a potential material with high hardness and high fracture toughness to be used as femoral head in total hip joint replacement.

KAISER ALUMINUM ALLOY 7050

Alloy Digest ◽  
2000 ◽  
Vol 49 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Heat Treating ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Kaiser Aluminum ◽  
Structural Parts ◽  
Very High

Abstract Kaiser Aluminum Alloy 7050 has very high mechanical properties including tensile strength, high fracture toughness, and a high resistance to exfoliation and stress-corrosion cracking. The alloy is typically used in aircraft structural parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: AL-366. Producer or source: Tennalum, A Division of Kaiser Aluminum.

Influence of additive composition on thermal and mechanical properties of β–Si3N4 ceramics

2004 ◽  
Vol 19 (11) ◽  
pp. 3270-3278 ◽  
Author(s):  
Xinwen Zhu ◽  
Hiroyuki Hayashi ◽  
You Zhou ◽  
Kiyoshi Hirao
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Fracture Toughness ◽  
Nitrogen Pressure ◽  
High Fracture Toughness ◽  
Oxygen Impurity ◽  
Thermal And Mechanical Properties ◽  
High Fracture ◽  
Doped Materials ◽  
Gas Pressure Sintering

Dense β–Si3N4 ceramics were fabricated from α–Si3N4 raw powder by gas-pressure sintering at 1900 °C for 12 h under a nitrogen pressure of 1 MPa, using four different kinds of additive compositions: Yb2O3–MgO, Yb2O3–MgSiN2, Y2O3–MgO, and Y2O3–MgSiN2. The effects of additive composition on the microstructure and thermal and mechanical properties of β–Si3N4 ceramics were investigated. It was found that the replacement of Yb2O3 by Y2O3 has no significant effect on the thermal conductivity and fracture toughness, but the replacement of MgO by MgSiN2 leads to an increase in thermal conductivity from 97 to 113 Wm-1K-1and fracture toughness from 8 to 10 MPa m1/2, respectively. The enhanced thermal conductivity of the MgSiN2-doped materials is attributed to the purification of β–Si3N4 grain and increase of Si3N4–Si3N4 contiguity, resulting from the enhanced growth of large elongated grains. The improved fracture toughness of the MgSiN2-doped materials is attributed to the increase of grain size and fraction of large elongated grains. However, the same thermal conductivity between the Yb2O3- and Y2O3-doped materials is related to not only their similar microstructures, but also the similar abilities of removing oxygen impurity in Si3N4 lattice between Yb2O3 and Y2O3. The same fracture toughness between the Yb2O3- and Y2O3-doped materials is consistent with their similar microstructures. This work implies that MgSiN2 is an effective sintering aid for developing not only high thermal conductivity (>110 Wm−1K−1) but also high fracture toughness (>10 MPa m1/2) of Si3N4 ceramics.

scholarly journals Automatic Evaluation of the Mechanical Properties of Steels Maraging using Digital Image Processing Techniques

2020 ◽  
Author(s):  
Angélica Alves Viana ◽  
Savio Lopes Rabelo ◽  
José Daniel de Alencar Santos ◽  
Venceslau Xavier de Lima Filho ◽  
Douglas De Araújo Rodrigues ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Maraging Steel ◽  
Raw Material ◽  
High Fracture Toughness ◽  
Mechanical Resistance ◽  
High Fracture ◽  
Traditional System ◽  
Transformation Methods ◽  
Processing Techniques

Some strategic sectors of the economy require that the raw material of their machines and equipment have mechanical properties that satisfy their use. Maraging steel is a material of great concern since it is necessary to have a high mechanical resistance associated with high fracture toughness. The traditional tests to determine the fracture toughness of this material before use in applications are the Charpy and KIC tests. However, this process is characterized by being exhaustive and requiring specialized and trained professionals. Thus, to reverse this situation, this work proposes a new approach to determine the mechanical properties of maraging steel. For this, initially, the method removes any artifacts present in the image resulting from the mode of acquisition. In sequence, this works tested the method Extended Minimum Transformation (EMT) and mathematical morphology to find these markers of the regions of the dimples. Then, the Adaptive Thresholding, Optimal Global Thresholdusing the Otsu Method and Watershed transformation methods were used to segment the dimples. In the end, the diameter of the dimples and the toughness of the material were calculated. Tests are carried out and compared with the result obtained by specialists using the traditional system to evaluate the proposed approach. The results obtained were satisfactory for the application because the proposed approach presented speed and precision to the conventional methods.

Preparation and Characterization of Reaction Sintering B4C/SiC Composite Ceramic

2014 ◽  
Vol 602-603 ◽  
pp. 536-539
Author(s):  
Hai Bin Sun ◽  
Yu Jun Zhang ◽  
Qi Song Li
Keyword(s):  
Fracture Toughness ◽  
High Performance ◽  
Bending Strength ◽  
Carbon Sources ◽  
High Hardness ◽  
High Strength ◽  
Composite Ceramic ◽  
High Fracture Toughness ◽  
Reaction Sintering ◽  
High Fracture

High hardness, high strength, high fracture toughness and low density are required for novel bulletproof materials. B4C/SiC composite ceramic is one of the most potential candidates. In this study, B4C/SiC composite ceramic was prepared by reaction sintering. The influence of B4C content, species and content of carbon, sintering temperature on the mechanical properties of B4C/SiC composite ceramic were studied. A high performance B4C/SiC composite ceramic was sintered at 1750°C for 30 min. Phenolic resin and carbon black were both chosen as carbon sources, whose favorable contents were 10wt%, 5wt%, respectively. The density of sintered bodies reduces with B4C content increases. To some extent, fracture toughness, bending strength improve initially and then deteriorate with the increase of B4C content whose optimal amount is 30wt%. The optimal fracture toughness and bending strength of the B4C/SiC composite ceramic are 5.07MPa·m1/2 and 487MPa, respectively. Meanwhile, the Viker-hardness of the sintered body is 30.2GPa, the density is as low as 2.82g/cm3.

Preparation of a Novel Poly(Methyl Methacrylate)-Dimethyl Diethoxysilane Nano-Composite

2007 ◽  
Vol 361-363 ◽  
pp. 491-494 ◽  
Author(s):  
Kyu Hyeon Lee ◽  
Yong Keun Lee ◽  
Bum Soon Lim ◽  
Sung Baek Cho ◽  
Sang Hoon Rhee
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Methyl Methacrylate ◽  
Bone Cement ◽  
Tetraethyl Orthosilicate ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Nano Composite ◽  
Poly Methyl Methacrylate

The poly(methyl methacrylate)/silica nano-composite made from trimethoxysilyl functionalized poly(methyl methacrylate) and dimethyl diethoxysilane was newly prepared and its apatite-forming ability and mechanical properties were evaluated comparing to poly(methyl methacrylate)/silica nano-composite made from trimethoxysilyl functionalized poly(methyl methacrylate) and tetraethyl orthosilicate. Its apatite-forming ability was similar to that of poly(methyl methacrylate)/silica nano-composite using tetraethyl orthosilicate but its fracture toughness was much improved. Its high fracture toughness might come from the less quantity of siloxane linkages in its structure because dimethyl diethoxysilane had only two ethoxysilane groups while tetraethyl orthosilicate had four ethoxysilane groups. From the results, it can be concluded that it has a possibility to be used as bioactive bone cement.

Correlation between microstructure and mechanical properties in silicon carbide with alumina addition

1993 ◽  
Vol 8 (7) ◽  
pp. 1635-1643 ◽  
Author(s):  
S.S. Shinozaki ◽  
J. Hangas ◽  
K.R. Carduner ◽  
M.J. Rokosz ◽  
K. Suzuki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Carbide ◽  
Analytical Electron Microscopy ◽  
High Strength ◽  
High Fracture Toughness ◽  
Sintered Body ◽  
High Fracture ◽  
High Fatigue ◽  
Alumina Addition

The microstructure of pressureless sintered silicon carbide (SiC) materials with alumina (Al2O3) addition was investigated using analytical electron microscopy and nuclear magnetic resonance. A sintered body with a density of higher than 99% theoretical was obtained with an addition of 5 wt.% Al2O3. The sintered body (SiC–Al2O3) has high strength, high fracture toughness, and high fatigue resistance. Its fracture toughness is approximately 5 MPa-m1/2, which is twice as high as that of pressureless sintered SiC materials with boron and carbon additions (SiC–B–C). The correlation between the microstructure and the mechanical properties is presented here. The starting β–SiC powder is mostly transformed to α–SiC with various polytype distributions during the sintering process. The microstructure has homogeneously distributed, fine, plate-like interlocking gains with a high aspect ratio. Well-developed basal planes form parallel and elongated boundaries, and the crystal structure is mostly the 6H polytype (56%) mixed with thin lamellar 4H.

Multifunctional Ti-Si-B-C-N Tribological Nanocomposite Coatings for Aerospace Applications

2007 ◽  
Vol 539-543 ◽  
pp. 173-180 ◽  
Author(s):  
In Wook Park ◽  
Brajendra Mishra ◽  
Kwang Ho Kim ◽  
John J. Moore
Keyword(s):  
Mechanical Properties ◽  
Photoelectron Spectroscopy ◽  
High Hardness ◽  
Systematic Investigation ◽  
304 Stainless Steel ◽  
High Fracture Toughness ◽  
Nanocomposite Coatings ◽  
High Fracture ◽  
X Ray ◽  
Wear Rates

Ti–B–C–N and Ti–Si–B–C–N nanocomposite coatings were deposited on AISI 304 stainless steel substrates by DC unbalanced magnetron sputtering from two (80mol% TiB2–20mol% TiC and 40mol% TiB2–60mol% TiC) composite targets in various Si target powers. The relationship among microstructures, mechanical properties, and tribologiacal properties was investigated. The synthesized Ti–B–C–N and Ti–Si–B–C–N coatings were characterized using x–ray diffraction (XRD) and x–ray photoelectron spectroscopy (XPS). These analyses revealed that the Ti–Si–B–C–N coatings are nanocomposites consisting of solid-solution (Ti,C,N)B2 and Ti(C,N) crystallites distributed in an amorphous TiSi2, SiC, and SiB4 matrix including some carbon, BN, CNx, TiO2, and B2O3 components. The addition of Si to the Ti–B–C–N coating led to percolation of amorphous TiSi2, SiC, and SiB4 phases. The Ti–Si–B–C–N coatings exhibited high hardness and H/E values, indicating high fracture toughness, of approximately 35 GPa and 0.098, respectively. Furthermore, the Ti–Si–B–C–N coatings exhibited very low wear rates ranging from ~3×10-7 to ~16×10-7 mm3/(N·m). The minimum friction coefficient of the Ti–Si–B–C–N coatings was approximately 0.15 at low Si target power between 25W and 50W. A systematic investigation on the microstructures, mechanical properties, and tribological properties of Ti–Si–B–C–N coatings prepared from two TiB2–TiC composite targets and one Si target is reported in this paper.

Micro Fracture Toughness Testing of TiAl Based Alloys with a Fully Lamellar Structure

2004 ◽  
Vol 842 ◽  
Author(s):  
K. Takashima ◽  
T. P. Halford ◽  
D. Rudinal ◽  
Y. Higo ◽  
M. Takeyama
Keyword(s):  
Fracture Toughness ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Testing Machine ◽  
High Fracture Toughness ◽  
Fracture Mechanisms ◽  
High Fracture ◽  
Fundamental Information ◽  
Micrometer Scale ◽  
Fully Lamellar

ABSTRACTA micro-sized testing technique has been applied to investigate the fracture properties of lamellar colonies in a fully lamellar Ti-46Al-5Nb-1W alloy. Micro-sized cantilever specimens with a size ≈ 10 × 10 × 50 μm3 were prepared by focused ion beam machining. Notches with a width of 0.5 μm and a depth of 5 μm were also introduced into the micro-sized specimens by focused ion beam machining. Fracture tests were successfully completed using a mechanical testing machine for micro-sized specimens at room temperature. The fracture toughness (KQ) values obtained were in the range 1.4–7 MPam1/2. Fracture surface observations indicate that these variations are attributable to differences in local lamellar orientations ahead of the notch. These fracture toughness values are also lower than those having been previously reported in conventional samples. This may be due the absence of significant extrinsic toughening mechanisms in these micro-sized specimens. Fracture mechanisms of these alloys are also considered on the micrometer scale. The results obtained in this investigation give important and fundamental information on the development of TiAl based alloys with high fracture toughness.

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