Effect of in-situ non-oxide bonding phases on fracture behaviour and microstructure of alumina-based castables with different bonding systems

2021 ◽  
Author(s):  
Renhong Yu ◽  
Jiwei Zhou ◽  
Guangxin Li ◽  
Liyuan Zhang ◽  
Xiaohui Zhang ◽  
...  
Keyword(s):  
Fracture Behaviour ◽  
Bonding Systems

In situ study on fracture behaviour of white etching layers formed on rails

2019 ◽  
Vol 180 ◽  
pp. 60-72 ◽  
Author(s):  
A. Kumar ◽  
A.K. Saxena ◽  
C. Kirchlechner ◽  
M. Herbig ◽  
S. Brinckmann ◽  
...  
Keyword(s):  
Fracture Behaviour ◽  
In Situ Study

Fracture behaviour of cast in-situ TiAl matrix composite reinforced with carbide particles

2018 ◽  
Vol 721 ◽  
pp. 1-7 ◽  
Author(s):  
J. Lapin ◽  
M. Štamborská ◽  
T. Pelachová ◽  
O. Bajana
Keyword(s):  
Matrix Composite ◽  
Fracture Behaviour ◽  
Carbide Particles

scholarly journals Influence of Erosive and Abrasive Cycling on Bonding of Different Adhesive Systems to Enamel: An In situ Study

2016 ◽  
Vol 27 (5) ◽  
pp. 548-555 ◽  
Author(s):  
Marina Ciccone Giacomini ◽  
◽  
Leslie Caroll Casas-Apayco ◽  
Camila Moreira Machado ◽  
Maria Cristina Carvalho de Almendra Freitas ◽  
...  
Keyword(s):  
Bond Strength ◽  
Orange Juice ◽  
Failure Modes ◽  
Ex Vivo ◽  
Adhesive Systems ◽  
Digital Microscope ◽  
Bonding Systems ◽  
Bovine Enamel ◽  
The Impact

Abstract This study evaluated the impact of orange juice on the bond strength (BS) of dentin bonding systems (DBSs) to enamel surface after simulation with an in situ/ ex vivo erosive cycling. One hundred and ninety two bovine enamel fragments (4x4x2mm) were obtained and randomized regarding superficial microhardness and distributed to palatal devices for 8 volunteers, in three phases (one for each DBS), containing 8 blocks, which were, allocated in 4 pairs. Daily, these pairs were subjected extraorally to the following conditions: CONT- neither erosive nor abrasive challenge; ERO- erosive challenge only; ABR- abrasive challenge only and ERO + ABR- with erosive and abrasive challenges. Erosive cycles (immersion in orange juice, 3 times/day/5 min/5 days) or/and abrasive challenges (electric toothbrush, 3 times/day/1 min/5 days) were performed. After these cycles, all specimens were restored with the adhesive systems Adper Scotchbond Multi Purpose (MP), Adper Single Bond 2 (SB) or Clearfil SE Bond (SE), and the composite resin Filtek Z250. After 7 days, sticks (area ≅1 mm2) were obtained and subjected to the microtensile bond strength test (μTBS) at 0.5 mm/min. Data was statistically analyzed by ANOVA and Tukey tests (a=0.05). Failure modes were determined using a digital microscope (40´). DBS was the only statistical significant factor. SE was the unique DBS not affected in any challenge, whereas MP and SB performed according to the scenario. The adhesive and mixed failures were predominant in all groups. Overall performance suggested that BS to enamel after erosive /abrasive challenged by orange juice was not affected and it was material-dependent.

scholarly journals Extruded-Calendered Sheets of Fully Recycled PP/Opaque PET Blends: Mechanical and Fracture Behaviour

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2360
Author(s):  
David Loaeza ◽  
Jonathan Cailloux ◽  
Orlando Santana Pérez ◽  
Miguel Sánchez-Soto ◽  
Maria Lluïsa Maspoch
Keyword(s):  
Fracture Behaviour ◽  
Raw Materials ◽  
Tensile Tests ◽  
Recycling Rate ◽  
Recycled Plastics ◽  
Microfibrillar Composites ◽  
Microfibrillar Structure ◽  
Work Of Fracture ◽  
O Phase

This work presents the experimental results of the mechanical and fracture behaviour of three polymeric blends prepared from two recycled plastics, namely polypropylene and opaque poly (ethylene terephthalate), where the second one acted as a reinforcement phase. The raw materials were two commercial degrees of recycled post-consumer waste, i.e., rPP and rPET-O. Sheets were manufactured by a semi-industrial extrusion-calendering process. The mechanical and fracture behaviours of manufactured sheets were analyzed via tensile tests and the essential work of fracture approach. SEM micrographics of cryofractured sheets revelated the development of in situ rPP/rPET-O microfibrillar composites when 30 wt.% of rPET-O was added. It was observed that the yield stress was not affected with the addition of rPET-O. However, the microfibrillar structure increased the Young’s modulus by more than a third compared with rPP, fulfilling the longitudinal value predicted by the additive rule of mixtures. Regarding the EWF analysis, the resistance to crack initiation was highly influenced by the resistance to its propagation owing to morphology-related instabilities during tearing. To analyze the initiation stage, a partition energy method was successfully applied by splitting the total work of fracture into two specific energetic contributions, namely initiation and propagation. The results revelated that the specific essential initiation-related work of fracture was mainly affected by rPET-O phase. Remarkably, its value was significantly improved by a factor of three with the microfibrillar structure of rPET-O phase. The results allowed the exploration of the potential ability of manufacturing in situ MFCs without a “precursor” morphology, providing an economical way to promote the recycling rate of PET-O, as this material is being discarded from current recycling processes.

scholarly journals Fracture behaviour of prepreg laminates studied by in-situ SEM mechanical tests

2018 ◽  
Vol 13 ◽  
pp. 1442-1446
Author(s):  
Simon Bard ◽  
Martin Demleitner ◽  
Markus Häublein ◽  
Volker Altstädt
Keyword(s):  
Fracture Behaviour ◽  
Mechanical Tests

In situ detection of the fracture behaviour of moso bamboo (Phyllostachys pubescens) by scanning electron microscopy

Holzforschung ◽  
2016 ◽  
Vol 70 (12) ◽  
pp. 1183-1190 ◽  
Author(s):  
Huanrong Liu ◽  
Xiaoqing Wang ◽  
Xiubiao Zhang ◽  
Zhengjun Sun ◽  
Zehui Jiang
Keyword(s):  
Fracture Toughness ◽  
Fracture Behaviour ◽  
Synergistic Effects ◽  
Microstructural Analysis ◽  
Interfacial Debonding ◽  
Moso Bamboo ◽  
Phyllostachys Pubescens ◽  
Vascular Bundles ◽  
Scanning Electron

Abstract The remarkable fracture toughness of bamboo culms is highly attributed to the proper embedding of the stiff fibre caps of the vascular bundles into the soft parenchyma matrix. In this study, the fracture behaviour of small specimens of moso bamboo (Phyllostachys pubescens) in tension and bending were investigated in situ with a scanning electron microscope (SEM) to visualise crack initiation and propagation within bamboo tissues and its interactions with the structural components (fibres and parenchyma tissues). Fracture surfaces were studied by field-emission SEM. The fracture of bamboo in either tension or bending was non-catastrophic, and cracks propagated in a tortuous manner with massive interfacial delamination. The stiff fibre bundles played an important role in restraining crack propagation, acting as bridges to inhibit cracks opening and also as “crack stoppers” inducing extensive crack-deflections. Microstructural analysis of the fractured surfaces revealed that substantial interfacial debonding, sliding and fibre pull-outs occurred at various length scales, which are believed to be effective in dissipating the crack energy. The synergistic effects of crack-deflection, crack-bridging and interfacial debonding are regarded to be mainly responsible for the remarkable fracture toughness of bamboo.

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