Prediction of Interfacial Surface Energy and Effective Fracture Energy From Contaminant Concentration in Polymer-Based Interfaces

2017 ◽  
Vol 84 (4) ◽  
Author(s):  
Denizhan Yavas ◽  
Ashraf F. Bastawros
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Surface Energy ◽  
Interfacial Fracture ◽  
Surface Concentration ◽  
Contaminant Concentration ◽  
Interfacial Fracture Mechanics ◽  
Interfacial Surface ◽  
Gibbs Adsorption Equation ◽  
Macroscopic Fracture

The principals of interfacial fracture mechanics and modified Gibbs adsorption equation are utilized to provide a predictive correlation for the macroscopic (effective) fracture toughness of polymer-based adhesive interfaces, exposed to varying level of contaminant concentration. The macroscopic fracture toughness measurement by double cantilever beam test exhibits a progressive deterioration with the increase of the contaminant surface concentration. The associated variation of fracture surface morphology exhibits ductile-to-brittle failure transition, caused by the contamination-induced suppression of plastic deformation within the adhesive layer. The corresponding intrinsic interfacial surface energy is extracted by finite-element simulation, employing surface-based cohesive elements. The modified Gibbs adsorption equation is utilized to correlate the contamination-induced degradation of the interfacial surface energy as a function of contaminant surface concentration. Interfacial fracture mechanics principals are applied to extend the correlation to the macroscopic fracture toughness of the interface. With additional examination of other systems, the proposed correlation may provide the basis for nondestructive evaluation of bond line integrity, exposed to different levels of contaminant.

An Engineering Model for Moisture Degradation of Polymer/Metal Interfacial Fracture Toughness

2005 ◽  
Author(s):  
Timothy P. Ferguson ◽  
Jianmin Qu
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Interfacial Fracture ◽  
Interfacial Fracture Toughness ◽  
Engineering Model ◽  
Metal Interface ◽  
Moisture Concentration ◽  
Interfacial Fracture Mechanics ◽  
Polymer Metal

Based on interfacial fracture mechanics and the hydrophobicity of the interface, en engineering model was developed in this paper. Using this model, one can predicted the degradation of interfacial fracture toughness of a polymer/metal interface once the moisture concentration near the interface is known.

Interfacial Fracture Analysis of Adhesive-Bonded Joints

2008 ◽  
Vol 33-37 ◽  
pp. 327-332 ◽  
Author(s):  
Won Seock Kim ◽  
Jung Ju Lee
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Adhesion Strength ◽  
Interfacial Fracture ◽  
Lap Joints ◽  
Bonded Joints ◽  
Load Bearing ◽  
Interfacial Fracture Mechanics ◽  
Adhesive Bonded Joints ◽  
Composite Steel

The failure in an adhesive-bonded structure starts at the interface, and the interfacial fracture is of interest whenever adhesion between different materials is concerned. One of primary factors limiting the application of adhesive-bonded joints to structural design is the lack of a good evaluation tool for adhesion strength to predict the load-bearing capacity of boned joints. The adhesion strength of composite/steel bonding has been evaluated using interfacial fracture mechanics characterization. The energy release rate of a composite/steel interfacial crack was compared with the fracture toughness of the interface, which was measured from bi-material end notched flexure (ENF) specimens, to predict the failure loads of bi-material lap joints. Fracture toughness, IIc G , was regarded as a property of the interface rather than a property of the adhesive. The results show that interfacial fracture mechanics characterization of adhesion strength can be a practical engineering tool for predicting the load-bearing capacities of adhesive-bonded joints.

On Relating Thermodynamic Work of Adhesion to Interfacial Fracture Toughness

1996 ◽  
Vol 445 ◽  
Author(s):  
Raymond A. Pearson ◽  
Thomas B. Lloyd
Keyword(s):  
Fracture Toughness ◽  
Strain Energy Release ◽  
Interfacial Fracture ◽  
Work Of Adhesion ◽  
Interfacial Fracture Toughness ◽  
Package Design ◽  
Silicon Chips ◽  
Interfacial Fracture Mechanics ◽  
Thermodynamic Work ◽  
Thermodynamic Work Of Adhesion

AbstractOrganic adhesives are commonly used in the microelectronics industry to bond silicon chips to a wide variety of substrates. The substrates include copper, silver, nickel / palladium, polyimide, and glass‐filled epoxies. The surfaces of these substrates are affected by the processing steps used in the manufacturing process used to produce the final package. The most common adhesives used in the assembly of microelectronic packages are epoxy‐based and there are numerous grades and types to chose from. Therefore, the packaging engineer is faced with the dilemma of what criterion to use to select the best adhesive for a particular package design.At the crux of the problem is how does one predict adhesion and how does one measure it? It is proposed that the surfaces play an important role in forming the interfacial bond and that strength of the mating surfaces can be characterized in terms of the thermodynamic work of adhesion. Roughness is also a factor but will not be dealt with here. The thermodynamic work of adhesion describes the energy to reversibly separate two surfaces (elastic). Interfacial fracture mechanics may be used to quantify the strain energy release rate for separating two surfaces and contains both elastic and inelastic contributions. This talk will contain a discussion of our studies on the use of a three liquid probe method to determine the thermodynamic work of adhesion and a mixed‐mode bending method to measure interfacial fracture toughness. Moreover, we will comment on the perils of relating the thermodynamic work of adhesion to the interfacial fracture toughness.

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