Preparation and toughening mechanism of Mo 2 NiB 2 ‐based cermets with SiC whiskers

2021 ◽  
Author(s):  
Xue Zhang ◽  
Jin Du ◽  
Guosheng Su ◽  
Peirong Zhang ◽  
Yujing Sun ◽  
...  
Keyword(s):  
Toughening Mechanism ◽  
Sic Whiskers

Microstructure and toughening mechanism of the 3Y-TZP/Al2O3 composite reinforced by SiC whiskers

1996 ◽  
Vol 31 (24) ◽  
pp. 6637-6643 ◽  
Author(s):  
Fang-Fang Xu ◽  
Li-Tai Ma ◽  
Shu-Lin Wen
Keyword(s):  
Toughening Mechanism ◽  
Al2o3 Composite ◽  
Sic Whiskers

Study on ZrC-20vol.%SiCw Ultrahigh Temperature Ceramics by Hot Pressing

2012 ◽  
Vol 557-559 ◽  
pp. 772-775 ◽  
Author(s):  
Jin Ping Li ◽  
Song He Meng ◽  
Zhi Bo Wang ◽  
Qing Liu ◽  
Yu Min Zhang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Hot Pressing ◽  
Sem Analysis ◽  
Toughening Mechanism ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Pull Out ◽  
Sic Whiskers ◽  
Ultrahigh Temperature

The ZrC-20vol.%SiCw ultrahigh temperature ceramics with relative density of 99.2% can be prepared by hot pressing at 1900 oC and 30MPa for 60 min. The mechanical properties and microstructure of the composite were studied. The flexural strength and fracture toughness reaches up to 626.17MPa, 5.03 MPa•m1/2, respectively. SEM analysis shows the microstructure of the ZrC-20vol.%SiCw is homogeneous and SiC whiskers are uniformly distributed around the ZrC grains, which inhibit the ZrC grain growth during sintering. The fracture surface of ZrC-20vol.%SiCw reveals a mixture of intergranular and transgranular failure, and SiC whiskers play a remarkable role in improving the strength and toughness of ZrC matrix. The toughening mechanism of the composite is mainly fine-grain strengthening and whisker pull-out.

HREM interface studies in SiC-whisker-reinforced Al2O3 and Si3N4 ceramics

1988 ◽  
Vol 46 ◽  
pp. 734-735
Author(s):  
W. Braue ◽  
R.W. Carpenter ◽  
D.J. Smith
Keyword(s):  
Analytical Data ◽  
Base Material ◽  
High Strength ◽  
Ceramic Composites ◽  
Good Thermal Stability ◽  
All Ceramic ◽  
Sic Whiskers ◽  
Base Composite ◽  
C 30 ◽  
Si3n4 Ceramics

Whisker and fiber reinforcement has been established as an effective toughening concept for monolithic structural ceramics to overcome limited fracture toughness and brittleness. SiC whiskers in particular combine both high strength and elastic moduli with good thermal stability and are compatible with most oxide and nonoxide matrices. As the major toughening mechanisms - crack branching, deflection and bridging - in SiC whiskenreinforced Al2O3 and Si3N41 are critically dependent on interface properties, a detailed TEM investigation was conducted on whisker/matrix interfaces in these all-ceramic- composites.In this study we present HREM images obtained at 400 kV from β-SiC/α-Al2O3 and β-SiC/β-Si3N4 interfaces, as well as preliminary analytical data. The Al2O3- base composite was hotpressed at 1830 °C/60 MPa in vacuum and the Si3N4-base material at 1725 °C/30 MPa in argon atmosphere, respectively, adding a total of 6 vt.% (Y2O3 + Al2O3) to the latter to promote densification.

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.

scholarly journals Synergistic strengthening mechanism of copper matrix composite reinforced with nano-Al2O3 particles and micro-SiC whiskers

2021 ◽  
Vol 10 (1) ◽  
pp. 62-72
Author(s):  
Huanran Lin ◽  
Xiuhua Guo ◽  
Kexing Song ◽  
Jiang Feng ◽  
Shaolin Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Erosion Resistance ◽  
Strengthening Mechanism ◽  
Copper Matrix ◽  
Heavy Duty ◽  
Arc Erosion ◽  
Comprehensive Performance ◽  
Sic Whiskers ◽  
Copper Matrix Composite ◽  
Time And Energy

Abstract Although Cu–Al2O3 composites have good comprehensive performance, higher mechanical properties and arc erosion resistance are still required to meet heavy-duty applications such as electromagnetic railguns. In this work, a novel hybrid SiCw/Cu–Al2O3 composite was successfully prepared by combining powder metallurgy and internal oxidation. The microstructure and mechanical behavior of the SiCw/Cu–Al2O3 composite were studied. The results show that nano-Al2O3 particles and micro-SiCw are introduced into the copper matrix simultaneously. Well-bonded interfaces between copper matrix and Al2O3 particles or SiCw are obtained with improved mechanical and arc erosion resistance of SiCw/Cu–Al2O3 composite. The ultimate tensile strength of the SiCw/Cu–Al2O3 composite is 508.9 MPa, which is 7.9 and 56.1% higher than that of the Cu–Al2O3 composite and SiCw/Cu composite, respectively. The strengthening mechanism calculation shows that Orowan strengthening is the main strengthening mechanism of the SiCw/Cu–Al2O3 composite. Compared with Cu–Al2O3 composite, the hybrid SiCw/Cu–Al2O3 composite has lower arc time and energy and better arc stability.

Finite Element Modeling of Damage Formation in Rubber-Toughened Polymer

2005 ◽  
Vol 297-300 ◽  
pp. 1019-1024
Author(s):  
Mitsugu Todo ◽  
Yoshihiro Fukuya ◽  
Seiya Hagihara ◽  
Kazuo Arakawa
Keyword(s):  
Finite Element ◽  
Damage Zone ◽  
Damage Model ◽  
Crack Tip ◽  
Optical Microscope ◽  
Toughening Mechanism ◽  
Element Analysis ◽  
Zone Formation ◽  
Macro Scale ◽  
Rubber Toughened

Microscopic studies on the toughening mechanism of rubber-toughened PMMA (RTPMMA) were carried out using a polarizing optical microscope (POM) and a transmission electron microscope (TEM). POM result showed that in a typical RT-PMMA, a damage zone was developed in the vicinity of crack-tip, and therefore, it was considered that energy dissipation due to the damage zone development was the primary toughening mechanism. TEM result exhibited that the damage zone was a crowd of micro-crazes generated around rubber particles in the vicinity of notch-tip. Finite element analysis was then performed to simulate such damage formations in crack-tip region. Macro-scale and micro-scale models were developed to simulate damage zone formation and micro-crazing, respectively, with use of a damage model. It was shown that the damage model introduced was successfully applied to predict such kind of macro-damage and micro-craze formations.

Decomposition of Trichloroethylene by Microwave‐Induced Plasma Generated from SiC Whiskers

1998 ◽  
Vol 145 (1) ◽  
pp. 229-235 ◽  
Author(s):  
Makoto Egashira ◽  
Yasuhiro Shimizu ◽  
Yuji Takao ◽  
Masaki Ono ◽  
Seiichi Sasada
Keyword(s):  
Microwave Induced Plasma ◽  
Sic Whiskers
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