Fracture Properties of Basalt Fibre Composites with Cured or Pyrolysed Matrix

2009 ◽  
Vol 409 ◽  
pp. 326-329
Author(s):  
Martin Černý ◽  
Zdeněk Chlup ◽  
Zbyněk Sucharda ◽  
Petr Glogar
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Mechanical Characteristics ◽  
Basalt Fibre ◽  
Fracture Properties ◽  
Chevron Notch ◽  
Fibre Composites ◽  
Material Fracture ◽  
Composite Samples ◽  
Scanning Electron

Composite materials based on polysiloxane matrix reinforced by basalt fibres were prepared in laboratories of the IRSM ASCR. The composite samples were pyrolysed at 400 ÷ 750 °C after moulding and curing at 250 °C. Measurement of several mechanical characteristics (flexural strength, fracture toughness, impact strength, and measurement of elasticity) demonstrates a favourable influence of pyrolysis in comparison with the cured-only composite material. Fracture toughness was measured by chevron-notch technique and fracture surfaces were investigated using a scanning electron microscopy.

Organoclay-reinforced polyethersulfone-modified epoxy-based hybrid nanocomposites

2011 ◽  
Vol 23 (7) ◽  
pp. 526-534 ◽  
Author(s):  
Yang Wang ◽  
Boming Zhang ◽  
Jinrui Ye
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Hybrid Nanocomposites ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Modified Epoxy ◽  
Scanning Electron

Hybrid nanocomposites were successfully prepared by the incorporation of polyethersulfone (PES) and organoclay into epoxy resin. They had higher fracture toughness than the prepared PES/epoxy blend and organoclay/epoxy nanocomposites. The microstructures of the hybrid nanocomposites were studied. They were comprised of homogeneous PES/epoxy semi-interpenetrating network (semi-IPN) matrices and organoclay micro-agglomerates made up of tactoid-like regions composed of ordered exfoliated organoclay with various orientations. The former was confirmed with dynamic mechanical analysis, scanning electron microscopy and transmission electron microscopy, while the latter was successfully observed with X-ray diffraction measurements, optical microscope, scanning electron microscope and transmission electron microscope. The improvement of their fracture toughness was due to the synergistic toughening effect of the PES and the organoclay and related to their microstructures.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.

Titanium Effect on Microstructure and Fracture toughness of Al2O3-BASED Composites

2011 ◽  
Vol 691 ◽  
pp. 32-36
Author(s):  
José G. Miranda-Hernández ◽  
Elizabeth Refugio-García ◽  
Eduardo Térres-Rojas ◽  
Enrique Rocha-Rangel
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Scanning Electron Microscopy ◽  
Fine Particles ◽  
Ceramic Matrix ◽  
High Energy ◽  
Titanium Content ◽  
Indentation Method ◽  
Sintered Temperature ◽  
Scanning Electron

The effect of different titanium additions (0.5, 1, 2, 3 and 10 vol. %), milling intensity (4 and 8 h) and sintered temperature (1500 and 1600 °C) on microstructure and fracture toughness of Al2O3-based composites was analyzed in this study. After high energy milling of a titanium and Al2O3mixtures, powder mixture presents fine distribution and good homogenization between ceramic and metal. After milling powders during 8 h they were obtained very fine particles with 200 nm average sizes. Microstructures of the sintered bodies were analyzed with a scanning electron microscopy, where it was observed that the microstructure presents the formation of a small and fine metallic net inside the ceramic matrix. From fracture toughness measurements realized by the fracture indentation method, it had that when titanium content in the composite increases, fracture toughness is enhanced until 83% with respect to the fracture toughness of pure Al2O3. This behavior is due to the formation of metallic bridges by titanium in the Al2O3matrix.

Effect of BN Short Fiber Content on Mechanical Properties of ZrB2-SiC UHTCs

2012 ◽  
Vol 512-515 ◽  
pp. 706-709 ◽  
Author(s):  
Chang Ling Zhou ◽  
Yan Yan Wang ◽  
Zhi Qiang Cheng ◽  
Chong Hai Wang ◽  
Rui Xiang Liu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Ceramic Composites ◽  
Short Fiber ◽  
Hot Pressing Sintering ◽  
Scanning Electron

ZrB2-20%volSiC ceramic composites with different volume of BN short fiber were fabricated by the hot-pressing sintering under 2000°C. The content of BN short fiber changed from 0 to 15vol%. The density, flexural strength, fracture toughness and thermal expansions coefficient were studied. The microstructures of the samples were observed by scanning electron microscopy. The results show that the introducing of BN short fiber into the ZrB2-20%volSiC lead to a serious of change to the mechanical properties of the ceramic. When the content of the BN short fiber is 10vol%, the flexural strength and fracture toughness reach 422.1MPa and 6.15 MPa•m 1/2 respectively. And the mechanism of the increasing toughness was studied.

Influence of stack sequence on the mechanical characteristics of hybrid composites analyzed using cone beam computed tomography and scanning electron microscopy

2020 ◽  
Vol 41 (12) ◽  
pp. 5059-5071
Author(s):  
Srinivas Shenoy Heckadka ◽  
Raghuvir Pai Ballambat ◽  
Vijay Kini Manjeshwar ◽  
Mathangi Kumar ◽  
Pranav Hegde ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Computed Tomography ◽  
Scanning Electron Microscopy ◽  
Cone Beam Computed Tomography ◽  
Mechanical Characteristics ◽  
Hybrid Composites ◽  
Cone Beam ◽  
Scanning Electron

SIZE REQUIREMENTS OF COMPACT SANDWICH SPECIMEN FOR TESTING OF BONE

2007 ◽  
Vol 07 (04) ◽  
pp. 419-431
Author(s):  
SATYA PRASAD PARUCHURU ◽  
ANUJ JAIN ◽  
XIAODU WANG
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Scanning Electron Microscopy ◽  
Bone Quality ◽  
Specimen Size ◽  
Element Analysis ◽  
Hierarchical Microstructure ◽  
Sandwich Specimen ◽  
Toughness Testing ◽  
Scanning Electron

It is well understood that bone quality deteriorates due to aging, disease, etc., and may be affected by factors at different length scales due to its hierarchical microstructure. Fracture toughness is one of the properties that assess bone quality. The compact sandwich (CS) specimen gives a better choice of bone sample size, and therefore suits a wide variety of fracture toughness testing needs and constraints. Reliable and statistically valid overall CS specimen size requirements are established in this paper; these serve as guidelines for choosing the CS specimen size. Finite element analysis (FEA) is used for simulating fracture toughness tests. Experimental fracture toughness tests are carried out to verify the FEA results. The experimental results are verified qualitatively by performing scanning electron microscopy (SEM) on the fractured specimen surfaces.

Effect of the Ratio of Co to Ni+Co on the Microstructures and Mechanical Properties of Ti(C, N)-Based Cermets

2017 ◽  
Vol 726 ◽  
pp. 292-296 ◽  
Author(s):  
Peng Wu ◽  
Shao Cun Liu ◽  
Xiu Rong Jiang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Rupture Strength ◽  
Hard Particle ◽  
Core Size ◽  
Transverse Rupture Strength ◽  
X Ray ◽  
The Core ◽  
Scanning Electron

The microstructures of the prepared Ti(C, N)-based cermets with various ratios of Co to Ni+Co were studied using X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Mechanical properties such as transverse rupture strength (TRS), fracture toughness (K1C) and hardness (HRA) were also measured. The results showed that when Ni was partly replaced by Co, the core size of hard particle and the thickness of rim phase changed. With the increasing of the ratio of Co to Ni+Co, the porosity of the cermets increased gradually, the fracture toughness of the cermets decreased gradually, the transverse rupture strength increased firstly and then decreased, the hardness changed slightly。When the ratio of Co to Ni+Co was 0.2, the cermets had better transverse rupture strength (TRS), which was characterized by fine grains and the moderate thickness of rim phase in the binder.

scholarly journals Механические свойства композитного покрытия SiC на графите, полученного методом замещения атомов

2021 ◽  
Vol 47 (20) ◽  
pp. 7
Author(s):  
А.С. Гращенко ◽  
С.А. Кукушкин ◽  
А.В. Осипов ◽  
А.В. Редьков
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Silicon Carbide ◽  
Mechanical Characteristics ◽  
Composite Coatings ◽  
Continuous Film ◽  
Silicon Melt ◽  
First Time ◽  
Initial Graphite ◽  
Scanning Electron

The mechanical properties of composite coatings made of silicon carbide on graphite are studied for the first time. For the deposition of coatings, a new method of annealing the initial graphite was used, which was in contact with a silicon melt in an atmosphere of carbon monoxide.The samples were studied by nanoindentation and scanning electron microscopy. It is shown that the formed coating consists of a continuous film of monocrystalline silicon carbide lying on the surface, dendrites and crystalline druses, with roots going deep into the sample through a system of pores. It is shown that the coating significantly increases the mechanical characteristics of the graphite surface, including the microhardness.

scholarly journals Beneficial effect of low BN additive on densification and mechanical properties of hot-pressed ZrB2–SiC composites

2021 ◽  
Vol 1 (2) ◽  
pp. 69-75
Author(s):  
Saber Haghgooye Shafagh ◽  
Shapour Jafargholinejad ◽  
Siyamak Javadian
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Crack Deflection ◽  
Crack Branching ◽  
Pressing Method ◽  
X Ray ◽  
Sic Composites ◽  
Different Characteristics ◽  
Scanning Electron ◽  
Consolidation Behavior

The incorporation of 1 wt% hexagonal BN (hBN) into ZrB2–30 vol% SiC could noticeably better the fracture toughness, hardness, and consolidation behavior of this composite. This research intended to scrutinize the effects of various amounts of hBN (0–5 wt%) on different characteristics of ZrB2–SiC materials. The hot-pressing method under 10 MPa at 1900 °C for 120 min was employed to sinter all designed specimens. Afterward, the as-sintered samples were characterized using X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and Vickers technique. The hBN addition up to 1 wt% improved relative density, leading to a near fully dense sample; however, the incorporation of 5 wt% of such an additive led to a composite containing more than 5% remaining porosity. The highest Vickers hardness of 23.8 GPa and fracture toughness of 5.7 MPa.m1/2 were secured for the sample introduced by only 1 wt% hBN. Ultimately, breaking large SiC grains, crack bridging, crack deflection, crack branching, and crack arresting were introduced as the chief toughening mechanisms in the ZrB2–SiC–hBN system.

Sign in / Sign up

Export Citation Format

Share Document