Characterization of Mode-II Interfacial Fracture Toughness of Ice/Metal Interfaces

2019 ◽  
Author(s):  
Denizhan Yavas ◽  
Ashraf Bastawros ◽  
Bishoy Dawood ◽  
Christopher Giuffre
Keyword(s):  
Fracture Toughness ◽  
Interfacial Fracture ◽  
Mode Ii ◽  
Interfacial Fracture Toughness ◽  
Metal Interfaces

An experimental study on interfacial fracture toughness of 3-D printed ABS/CF-PLA composite under mode I, II, and mixed-mode loading

2019 ◽  
pp. 089270571987486 ◽  
Author(s):  
Abdul Samad Khan ◽  
Aaqib Ali ◽  
Ghulam Hussain ◽  
Muhammad Ilyas
Keyword(s):  
Fracture Toughness ◽  
Mixed Mode ◽  
Interfacial Fracture ◽  
Mode I ◽  
Mode Ii ◽  
Interfacial Fracture Toughness ◽  
Fused Deposition ◽  
Specimen Test ◽  
Nozzle Temperature ◽  
Printing Speed

Multimaterial structures made using fused deposition modeling (FDM) offer an attractive prospect for enhancing their mechanical properties and functionality. In this study, the interfacial fracture toughness of a unidirectional hybrid composite fabricated by FDM was studied through mechanical testing. The composite structure comprises acrylonitrile butadiene styrene and carbon fiber-reinforced polylactic acid. Since, de-adhesion or bond failure at the interface can occur under a combination of the different fracture modes, therefore, interfacial fracture toughness, in terms of the critical energy release rate, was characterized using double cantilever beam specimen test for mode I, end-notched flexural specimen test for mode II, and mixed-mode bending specimen test for mixed-mode I/II. Effects of varying process parameters, like printing speed and nozzle temperature, on the interfacial fracture toughness in mode I and II were also investigated. It was found that increasing the nozzle temperature and printing speed enhance the fracture toughness, both in mode I and II, but the effect of increasing nozzle temperature on mode II fracture toughness was quite significant.

scholarly journals Mode II Fracture Analysis of GNP/Epoxy Nanocomposite Film on a Substrate

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2823
Author(s):  
Shiuh-Chuan Her ◽  
Kai-Chun Zhang
Keyword(s):  
Fracture Toughness ◽  
Elastic Modulus ◽  
Nanocomposite Film ◽  
Epoxy Matrix ◽  
Interfacial Fracture ◽  
Mode Ii ◽  
Interfacial Fracture Toughness ◽  
Mode Ii Fracture ◽  
Mode Ii Fracture Toughness ◽  
Film Substrate

Epoxy resin with excellent mechanical properties, chemical stability, and corrosion resistance has been widely used in automotive and aerospace industries. A thin film of epoxy deposited on a substrate has great application in adhesive bonding and protective coating. However, the intrinsic brittleness of epoxy with a relatively low fracture toughness limits its applications. In this work, graphene nanoplatelets (GNP) were added to the epoxy resin to enhance its toughness, hardness, and elastic modulus. A series of nanocomposites with different loadings of GNP were fabricated. Ultrasonic sonication in combination with surfactant Triton X-100 were employed to disperse GNP in the epoxy matrix. A nanocomposite film with a thickness of 0.3 mm was deposited on an Al substrate using a spinning coating technology. The hardness and elastic modulus of the nanocomposite film on the Al substrate were experimentally measured by a nanoindentation test. Analytical expression of the mode II interfacial fracture toughness for the nanocomposite film on an Al substrate with an interfacial edge crack was derived utilizing the linear elastic fracture mechanics and Euler’s beam theory. End-notched flexure (ENF) tests were conducted to evaluate the mode II fracture toughness. It was found that the hardness, elastic modulus, and mode II fracture toughness of the nanocomposite film reinforced with 1 wt % of GNP were improved by 71.8%, 63.2%, and 44.4%, respectively, compared with the pure epoxy. The presence of much stiff GNP in the soft epoxy matrix prompts toughening mechanisms such as crack deflection and crack pinning, resulting in the improvements of the fracture toughness, hardness, and elastic modulus. Microscopic observation for the nanocomposite was examined by scanning electron microscopy (SEM) to investigate the dispersion of GNPs in the epoxy matrix. The performance of a nanocomposite film deposited on a substrate was rarely studied, in particular, for the interfacial fracture toughness of the film/substrate composite structure. Utilizing the theoretical model in conjunction with the ENF experimental test presented in this study, an accurate determination of the mode II interfacial fracture toughness of film/substrate composite structure is made possible.

Mechanical and Chemical Characterization of a Metal-Bioceramic Interface

1989 ◽  
Vol 153 ◽  
Author(s):  
Mark J. Filiaggi ◽  
N. A. Coombs ◽  
R.M. Pilliar
Keyword(s):  
Fracture Toughness ◽  
High Resolution ◽  
Bond Strength ◽  
Chemical Characterization ◽  
Interfacial Fracture ◽  
Adhesive Bond ◽  
Interfacial Fracture Toughness ◽  
Implant Fixation ◽  
Resolution Electron

AbstractPlasma sprayed Hydroxyapatite (HA) coatings are applied to metal prostheses to allow for implant fixation through chemical bonding of the coating with surrounding bone tissue. Without a well-adhering coating, this fixation is threatened. Thus, a thorough characterization of the metal / ceramic interface is necessary. This study used a novel composite short bar interfacial fracture toughness technique with high resolution electron spectroscopic imaging to examine Ti-6AI-4V plasma spray coated with 100μm of HA. For this system, an interfacial fracture toughness value of 1.31 +/− 0.08 MPa·m1/2 was obtained, with a corresponding tensile adhesive bond strength of 6.7 +/− 1.5 MPa. High resolution ESI revealed distinct phosphorous segregation to the interface and diffusion into the underlying titanium. A 24-hour post-heat treatment at 960°C greatly increased the bond strength at this interface. Observations from ESI suggested that this effect may be due to enhanced diffusion of both phosphorous and calcium into the metal substrate.

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