Effects of Interface Edge Angle on Distributed Stress near Edge of Interface of Bonded Dissimilar Materials

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.

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Singularity at the Interface Edge of Bonded Transversely Isotropic Piezoelectric Dissimilar Materials. 2nd Report. The Solution for an Interface Edge under Axisymmetric Deformation.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A ◽

10.1299/kikaia.66.1590 ◽

2000 ◽

Vol 66 (648) ◽

pp. 1590-1596

Author(s):

Jinquan XU ◽

Yoshiharu MUTOH

Keyword(s):

Dissimilar Materials ◽

Transversely Isotropic ◽

Axisymmetric Deformation ◽

Interface Edge

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Thermal Stress Field at the Interface Edge in Dissimilar Materials.

Journal of the Society of Materials Science Japan ◽

10.2472/jsms.48.365 ◽

1999 ◽

Vol 48 (4) ◽

pp. 365-375 ◽

Cited By ~ 1

Author(s):

Tadanobu INOUE ◽

Shiro KUBO

Keyword(s):

Thermal Stress ◽

Stress Field ◽

Dissimilar Materials ◽

Thermal Stress Field ◽

Interface Edge

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Effect of Free Surface Shape at Edge of Interface on Bonding Strength of Ceramic to Metal Joint

Volume 6: Materials and Fabrication, Parts A and B ◽

10.1115/pvp2008-61224 ◽

2008 ◽

Author(s):

Masayoshi Tateno ◽

Yoshiaki Hagiwara ◽

Kunio Kokubo

Keyword(s):

Silicon Nitride ◽

Bonding Strength ◽

Fracture Pattern ◽

Surface Shape ◽

Interface Plane ◽

Free Surfaces ◽

Edge Angle ◽

Metal Joint ◽

Free Surface Shape ◽

Interface Edge

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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