Effect of nanosilica with different interfacial structures on mechanical properties of polyimide/SiO 2 composites

2019 ◽  
Vol 137 (16) ◽  
pp. 48595 ◽  
Author(s):  
Mengfan Liang ◽  
Yu Wang ◽  
Shuhong Sun ◽  
Wenlong Yang
Keyword(s):  
Mechanical Properties ◽  
Interfacial Structures

scholarly journals Advanced superhard composite materials with extremely improved mechanical strength by interfacial segregation of dilute dopants

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tomohiro Nishi ◽  
Katsuyuki Matsunaga ◽  
Takeshi Mitsuoka ◽  
Yasuyuki Okimura ◽  
Yusuke Katsu
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Structural Transition ◽  
Bending Strength ◽  
Single Layer ◽  
Interfacial Strength ◽  
Advanced Composite ◽  
Atomic Segregation ◽  
Advanced Composite Materials ◽  
Interfacial Structures

AbstractControl of heterointerfaces in advanced composite materials is of scientific and industrial importance, because their interfacial structures and properties often determine overall performance and reliability of the materials. Here distinct improvement of mechanical properties of alumina-matrix tungsten-carbide composites, which is expected for cutting-tool application for aerospace industries, is achieved via interfacial atomic segregation. It is found that only a small amount of Zr addition is unexpectedly effective to significantly increase their mechanical properties, and especially their bending strength reaches values far beyond those of conventional superhard composite materials. Atomic-resolution STEM observations show that doped Zr atoms are preferentially located only at interfaces between Al2O3 and WC grains, forming atomic segregation layers. DFT calculations indicate favorable thermodynamic stability of the interfacial Zr segregation due to structural transition at the interface. Moreover, theoretical works of separation demonstrate remarkable increase in interfacial strength through the interfacial structural transition, which strongly supports reinforcement of the interfaces by single-layer Zr segregation.

The Structure and Properties of MoSi2-Mo5Si3 Composites

1992 ◽  
Vol 273 ◽  
Author(s):  
H. Kung ◽  
D. P. Mason ◽  
A. Basu ◽  
H. Chang ◽  
D. C. Van Aken ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Second Phase ◽  
Structure And Properties ◽  
Transmission Electron ◽  
Interfacial Structures ◽  
Two Phases ◽  
Hardness Values

ABSTRACTThe addition of Mo5Si3 as a reinforcing second phase in a MoSi2 matrix has been investigated for possible high temperature strengthening effects. MoSi2 with up to 45 vol % Mo5Si3 was fabricated using powder metallurgy (PM) and arc-casting (AC) techniques. Effects of processing routes, which result in different microstructures, on their mechanical properties are given. PM composites, which have an equiaxed microstructure, exhibit a limited increase in hardness. Higher hardnesses are observed in script-structured AC eutectics and Er-modifiedeutectics throughout the temperatures studied (25–1300°C). Crack propagation paths induced by indentation show long transphase cracks in the AC materials vs short intergranular and interphase cracks in the PM composites at high temperatures.Transmission electron microscopy discloses that the interface in the AC composites has a low-index orientation relationship between the two phases and shows regularly faceted interfacial structures, while planar interfaces are found in the PM composites. These observations suggest the interface is stronger and lower in energy in the AC composites, which is consistent with the higher hardness values and long transphase cracks observed.Dislocation analysis shows the presence of ordinary dislocations (<100>, <110> and 1/2<111>) in MoSi2 in the as-fabricated composites. These types of dislocation are also responsible for the high temperature plastic deformation in compression in both the monolithic MoSi2 and the composites. <331> types of dislocation are only found in MoSi2 either near the interface of the AC composites or in materials deformed below 1000°C.

scholarly journals Effect of Interfacial Structure on Mechanical Properties of Graphene Reinforced Al2O3–WC Matrix Ceramic Composite

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1374
Author(s):  
Xuchao Wang ◽  
Jun Zhao ◽  
Enzhao Cui ◽  
Xianhua Tian ◽  
Zhefei Sun
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Interfacial Adhesion ◽  
Ceramic Composite ◽  
Interfacial Shear Strength ◽  
Interfacial Shear ◽  
Adhesion Energy ◽  
Interfacial Structure ◽  
Interfacial Structures ◽  
Interfacial Adhesion Energy

The interfacial structures and interfacial bonding characteristics between graphene and matrix in graphene-reinforced Al2O3–WC matrix ceramic composite prepared by two-step hot pressing sintering were systematically investigated. Three interfacial structures including graphene–Al2O3, graphene–Al2OC and graphene-WC were determined in the Al2O3–WC–TiC–graphene composite by TEM. The interfacial adhesion energy and interfacial shear strength were calculated by first principles, and it has been found that the interfacial adhesion energy and interfacial shear strength of the graphene–Al2OC interface (0.287 eV/nm2, 59.32 MPa) were far lower than those of graphene–Al2O3 (0.967 eV/nm2, 395.77 MPa) and graphene–WC (0.781 eV/nm2, 229.84 MPa) interfaces. Thus, the composite with the strong and weak hybrid interfaces was successfully obtained, which was further confirmed by the microstructural analysis. This interfacial structure could induce strengthening mechanisms such as load transfer, grain refinement, etc., and toughening mechanisms such as crack bridging, graphene pull-out, etc., which effectively improved mechanical properties.

Effects of annealing on the interfacial structures and mechanical properties of hot roll bonded Al/Mg clad sheets

2020 ◽  
Vol 792 ◽  
pp. 139673
Author(s):  
Pengju Wang ◽  
Zejun Chen ◽  
Chao Hu ◽  
Boxin Li ◽  
Taiqian Mo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Interfacial Structures
Sign in / Sign up

Export Citation Format

Share Document