Fracture Toughness and Hardness of Ti(C0.7N0.3)-19Mo2C-xNbC-24Ni

2015 ◽  
Vol 1088 ◽  
pp. 255-259 ◽  
Author(s):  
Hiroyuki Hosokawa ◽  
Kiyotaka Katou ◽  
Koji Shimojima ◽  
Ryoichi Furushima ◽  
Akihiro Matsumoto
Keyword(s):  
Fracture Toughness ◽  
Phase Separation ◽  
The Other ◽  
Binder Phase ◽  
Hard Phase ◽  
Other Hand

The fracture toughness and hardness of Ti (C0.7N0.3)-19Mo2C-xNbC-24Ni cermets (x= 0, 5, 20) were studied. Fracture toughness of 5 NbC was the largest, and it of 20 NbC was the lowest. The microstructures of all the cermets consisted of Ti (C,N) and solid soluted Ti (C,N) hard phase, and Ni binder phase. The solid soluted Ti (C,N) surrounded Ti (C,N), namely, core-rim structures were observed in 0NbC and 5NbC. On the other hand, the isolated Ti (C,N) and solid soluted Ti (C,N) were observed in 20NbC, as a result of the phase separation between Ti (C,N) core and solid soluted Ti (C,N).

Microstructure, Mechanical Properties, Sintering and Fracture Behavior of Ti(C, N) Based Cermets Granules/Ti(C, N) Based Cermets Composite

2020 ◽  
Vol 837 ◽  
pp. 139-145
Author(s):  
Ai Jun Liu ◽  
Gang Li ◽  
Ning Liu ◽  
Ke Bei Chen ◽  
Hai Dong Yang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Relative Density ◽  
Fracture Behavior ◽  
Rupture Strength ◽  
Binder Phase ◽  
Hard Phase ◽  
Opposite Trend ◽  
The Matrix ◽  
Sintering Properties

Effect of Ti (C,N) based cermets granule on the microstructure, mechanical properties, sintering and fracture behavior of Ti (C,N) based cermets was investigated. Results show that the Ti (C,N) based cermets granules distribute in the matrix homogeneously. A nanoindentation study was performed on hard phase and binder phase in the matrix and granule. With the increase of granules content, sintering properties is worse. With the increase of granules content, transverse rupture strength (TRS) and relative density decrease gradually, while the hardness has an opposite trend. The fracture toughness increases firstly with increasing granule, and then decreases with the further increase of granules. Higher fracture toughness of the cermets is mainly owing to the crack branch and higher fracture energy of coarse granule.

Effect of Manganese Addition on Strength and Fracture Toughness in Mg-6Al-1Zn Alloy

2006 ◽  
Vol 306-308 ◽  
pp. 857-862 ◽  
Author(s):  
Taisuke Sasaki ◽  
Tokuteru Uesugi ◽  
Yorinobu Takigawa ◽  
Kenji Higashi
Keyword(s):  
Fracture Toughness ◽  
Magnesium Alloy ◽  
Yield Strength ◽  
Ductile Fracture ◽  
Manganese Content ◽  
Experimental Results ◽  
The Other ◽  
Excessive Amount ◽  
Void Coalescence ◽  
Other Hand

The effect of manganese on strength and fracture toughness was investigated using five kinds of Mg-6Al-1Zn alloys. From the experimental results, the yield strength increased with increasing in manganese content until manganese content reached 0.14 wt. %. On the other hand, further increase in yield strength was not observed in case larger than 0.14 % of manganese was added. In addition, fracture toughness decreases with increasing manganese content. Fracture of magnesium alloy was ductile fracture by void coalescence. Adding excessive amount of manganese caused the increase in the presence of inclusions. This kind of particle easily became the nucleus of microvoid. As a conclusion, manganese should be added so that coarse manganese-bearing particle is not formed. Thus, 0.14 wt. % of manganese should be added to Mg-6Al-1Zn alloy in order to develop the alloy with well-balanced relationship between strength and fracture toughness.

Growth of InGaN Films by MBE at the Growth Temperature of GaN

1995 ◽  
Vol 395 ◽  
Author(s):  
R. Singh ◽  
T.D. Moustakas
Keyword(s):  
Phase Separation ◽  
Spinodal Decomposition ◽  
Growth Temperature ◽  
Composition Range ◽  
The Other ◽  
Entire Composition Range ◽  
Other Hand ◽  
Ingan Alloys

ABSTRACTWe report the growth of InGaN alloys over practically the entire composition range at the growth temperature of GaN (700–800 °C) by MBE. We found that when the grown films are thick (> 0.3 μm), incorporation of more than about 30% indium results in phase separation of InN, which is consistent with spinodal decomposition. On the other hand we discovered that such phase separation is absent in thin InGaN films ( < 600Å) grown as GaN/InGaN/GaN heterostructures. In such configurations we were able to incorporate up to 81% In, which is the highest yet reported.

Non-Stoichiometric Transfer of Complex Oxides by Pulsed Laser Deposition at Low Fluences

1995 ◽  
Vol 397 ◽  
Author(s):  
B. Dam ◽  
J.H. Rector ◽  
J. Johansson ◽  
DG. DE Groot ◽  
R. Griessen
Keyword(s):  
Phase Separation ◽  
Pulsed Laser Deposition ◽  
Volume Diffusion ◽  
Pulsed Laser ◽  
Target Surface ◽  
Complex Oxides ◽  
The Other ◽  
Laser Deposition ◽  
Other Hand

ABSTRACTWe provide evidence that non-stoichiometric ablation of YBa2Cu3O7δ at low fluences is due to a phase separation of the target surface. On the other hand, in SrTiO3 we find at low fluences evidence for preferential ablation which is assisted by volume-diffusion. As a result, the Sr/Ti ratio of the ablated films can be tuned by choosing the appropriate fluence.

Initial Phase Formation and Distribution in the Pt-GexSi1−x and Cr-GexSi1−x Systems

1990 ◽  
Vol 181 ◽  
Author(s):  
Q. Z. Hong ◽  
J. W. Mayer
Keyword(s):  
Phase Separation ◽  
Phase Formation ◽  
Initial Phase ◽  
The Other ◽  
Other Hand

ABSTRACTMetal-GeSi reactions have been investigated in the Pt-GeSi and Cr-GeSi systems. Pt started to diffuse into and react with the alloys at 250 °C. The reacted region consisted of a uniform mixture of Pt2Si and Pt2Ge, with the same ratios of Ge to Si as those in the unreacted region. On the other hand, the Cr-GeSi reaction was induced by Ge motion at 375 °C. As a result a two-layer phase separation was observed. A Si-rich ternary layer was sandwiched between a germanide layer and the unreacted alloy

Development of Ceramic Engine Parts for Heat Insulated Engine

1990 ◽  
Author(s):  
Hideo Kawamura
Keyword(s):  
Fracture Toughness ◽  
Materials Design ◽  
Design Methods ◽  
Flaw Size ◽  
The Other ◽  
Combustion Chambers ◽  
Test Pieces ◽  
Other Hand ◽  
Calculation Results

In order to develop a ceramics engine with heat insulated combustion chambers, the strength of engine parts made of ceramics materials, design methods of the parts and triborogical features were studied for producing ceramics engine. In order to use the ceramics materials mainly Si3N4 with a suitable strength and fracture toughness, the correlation of strength and pore or flaw size or microstructures were investigated. On the other hand, designing methods were studied by using the calculation results of F. E. M on the practical engine and the strength of ceramics. Also, we investigated the characteristics of triborogical factors on the test pieces made of ceramics materials. In the result, we have achieved to produce the ceramics engine with a satisfactory durability and a lower friction through very severe tests.

Phase Separation in Sol-Gel Systems of Organic-Inorganic Hybrids

2006 ◽  
Vol 45 ◽  
pp. 759-768
Author(s):  
Kazuki Nakanishi ◽  
Kazuyoshi Kanamori
Keyword(s):  
Phase Separation ◽  
Hybrid Materials ◽  
Sol Gel ◽  
Surface Hydrophobicity ◽  
The Other ◽  
Inorganic Hybrid ◽  
Surface Hydrophilicity ◽  
Other Hand ◽  
Sol Gel Process ◽  
Polymerization Induced Phase Separation

Organic-inorganic hybrid monoliths with well-defined macropores and/or mesopores have been synthesized by a sol-gel process accompanied by polymerization-induced phase separation. Using aklyltrialkoxysilanes and alkylene-bridged alkoxysilanes, two different categories of organo-siloxane networks have been characterized in view of macroporoisity based on phase separation as well as mesoporosity based on supramolecular templating by surfactants. The alkyl-terminated polysiloxane network exhibited substantial surface hydrophobicity together with the mechanical flexibility. On the other hand, the alkylene-bridged network behaved much more similarly to those prepared from tetraalkoxysilanes with regard to surface hydrophilicity, mechanical rigidness and mesopore-forming ability. Supramolecular templating of mesopores embedded in the gel skeletons comprising well-defined macroporous network has proven to give wide variety of hierarchically designed macro-mesoporous organic-inorganic hybrid materials.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Phase separation in sol gel-derived ceramic films of silica-zirconia, alumina-zirconia, and titania-zirconia system

1994 ◽  
Vol 52 ◽  
pp. 646-647
Author(s):  
J. Tong ◽  
L. Eyring
Keyword(s):  
Fracture Toughness ◽  
Phase Separation ◽  
Sol Gel ◽  
Great Influence ◽  
High Strength ◽  
Chemical Durability ◽  
Separation Method ◽  
Toughening Mechanism ◽  
Ceramic Films ◽  
Zirconia Toughened Alumina

There is increasing interest in composites containing zirconia because of their high strength, fracture toughness, and its great influence on the chemical durability in glass. For the zirconia-silica system, monolithic glasses, fibers and coatings have been obtained. There is currently a great interest in designing zirconia-toughened alumina including exploration of the processing methods and the toughening mechanism.The possibility of forming nanocrystal composites by a phase separation method has been investigated in three systems: zirconia-alumina, zirconia-silica and zirconia-titania using HREM. The morphological observations initially suggest that the formation of nanocrystal composites by a phase separation method is possible in the zirconia-alumina and zirconia-silica systems, but impossible in the zirconia-titania system. The separation-produced grain size in silica-zirconia system is around 5 nm and is more uniform than that in the alumina-zirconia system in which the sizes of the small polyhedron grains are around 10 nm. In the titania-zirconia system, there is no obvious separation as was observed in die alumina-zirconia and silica-zirconia system.

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