scholarly journals Effect of interface edge angle on stress distribution near the interface edge of bonded dissimilar materials

2019 ◽  
Vol 6 (3) ◽  
pp. 18-00561-18-00561 ◽  
Author(s):  
Syunsuke MURAOKA ◽  
Reiichi TOKUMOTO ◽  
Yuki NAKAYAMA ◽  
Takashi TOMINAGA ◽  
Masayoshi TATENO
2018 ◽  
Vol 2018.26 (0) ◽  
pp. 203
Author(s):  
Syunsuke MURAOKA ◽  
Reiichi TOKUMOTO ◽  
Yuki NAKAYAMA ◽  
Takashi TOMINAGA ◽  
Masayoshi TATENO

2017 ◽  
Vol 2017.25 (0) ◽  
pp. 208
Author(s):  
Yuki NAKAYAMA ◽  
Takashi TOMINAGA ◽  
Eiichiro YOKOI ◽  
Masayoshi TATENO

Author(s):  
Masayoshi Tateno ◽  
Yohei Hatano ◽  
Kunio Kokubo

Selection of the optimum shape for interface edge can produce significant increases in the strength of bonded dissimilar materials such as ceramic to metal joints. The focus of this study is to clarify an effect of interface edge shape on bonding strength of ceramic to metal joint. Each plate Si3N4 to Ni joint with arc interface of convexity or concavity is produced by Electric Discharge machining. The arc interface is characterized by edge angle defined as a configuration angle between tangential line at the edge of the interface and the free surface of the ceramic. Each joint is bonded at high temperature by using thin braze metal under vacuum and slowly cooled. A good fit on each bonded face is achieved in this process. The dependence of the bonding strength on the edge angle is experimentally clarified. The result shows that changing the edge angle from the right angle improves the bonding strength since it decreases the residual stress near edge of the interface. The highest bonding strength always appears at the identical interface condition where fracture pattern changes. It appears that the optimum edge angle for obtaining the highest bonding strength depends on bonding temperature.


1999 ◽  
Vol 586 ◽  
Author(s):  
Masayoshi Tateno ◽  
Yasushi Fukuzawa ◽  
Shigeru Nagasawa ◽  
Hiroshi Sakuta

ABSTRACTIn order to evaluate the practical strength of a joint and its fracture mode, it is important to find the stress distribution near the edge of the interface by analyses of strength and fracture. The index of stress singularity based on theoretical analysis is a useful tool to indicate the stress distribution.In this paper, investigations on the evaluation of the practical strength of bonded dissimilar materials based on the stress singularity are carried out. The secant stiffness module, which was used for plastics analysis, was applied to the evaluation of thermal elastoplastic behavior near the interface. Spherical conditions of the interface shape were used for the evaluation of stress behavior and the experiment of bonding strength. The relationship between the index of stress singularity, λ, and the practical strength of the bonded TiB2-Ni system was investigated by comparing theoretical λ, which was determined by substituting the secant stiffness module into Bogy's eigenequation, with the practical strength in the edge angle of the interface between 60° and 90° The correlation factor of the relationship between λ and the practical bonding strength of the TiB2-Ni system was found positive. These results show that the structural design of a geometrical interface which is getting a higher strength joint based on the index of stress singularity is verified experimentally.


2011 ◽  
Vol 383-390 ◽  
pp. 887-892
Author(s):  
Alireza Fallahi Arezoodar ◽  
Ali Baladi

In dissimilar material joints, failure often occurs along the interface between two materials due to stress singularity. Stress distribution and its concentration depend on materials and geometry of the junction as the stress concentration depends on grain orientation and its stiffness matrix of neighboring grains in micro-scale. Inhomogenity of stress distribution at the interface of junction of two materials with different elastic modules and stress concentration in this zone are the main factors resulting in rupture of the junction. Effect of materials properties, thickness, and joining angle at the interface of aluminum-polycarbonate will be discussed in this paper. Computer simulation and finite element analysis by ABAQUS showed that convex interfacial joint leads to stress reduction at junction corners in compare with straight joint. This finding is confirmed by photoelastic experimental results.


Author(s):  
Masayoshi Tateno ◽  
Yoshiaki Hagiwara ◽  
Kunio Kokubo

The focus of this study is to clarify the effect of the interface edge shape on the bonding strength of ceramic to metal joint. Each silicon nitride to copper joint plate with arc-shaped free surfaces edge was produced by Electric Discharge machining (EDM). The interface edge shape was characterized by defining the edge angle as a configuration angle between the interface plane and tangential line at the arc edge of the bonded interface. Each joint was bonded at high temperature using thin braze metal under vacuum and slowly cooled. Good fit was achieved at each bonded face in this process. The dependence of the bonding strength on the edge angle was experimentally clarified in Silicon nitride to Copper joint with arc-shaped free surfaces. The result shows that changing the edge angle from right angle improves bonding strength since it decreases residual stress near the interface edge. The highest bonding strength appears at the specific interface where the fracture pattern changes. It also shows that secondary machining, which cuts both edges into optimum geometrical conditions after bonding, can improve bonding strength.


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