Dependence of bonding strength and variations in residual stress on interface wedge angles and bonding temperature conditions

MRS Advances ◽  
2020 ◽  
Vol 5 (33-34) ◽  
pp. 1765-1774
Author(s):  
Shunsuke Muraoka ◽  
Masayoshi Tateno
Keyword(s):  
Residual Stress ◽  
Bonding Strength ◽  
Bonding Temperature ◽  
Wedge Angle ◽  
Fracture Pattern ◽  
Experimental Results ◽  
Joint System ◽  
Stress Variation ◽  
Temperature Conditions ◽  
Interface Edge

AbstractResidual stress can considerably weaken systems with ceramics-to-metal joints. Herein, we investigate the dependence of bonding strength and residual stress variation of a ceramics-to-metal joint system on the interface wedge angle and bonding temperature condition. First, disparity between large-scale displacement models with varying work-hardening parameters was confirmed using thermal elastoplastic Finite Element Method (FEM) analysis. Each interface wedge shape was set to a plane surface to compare FEM results to experimental results related to the effect of the interface wedge angle on the practical bonding strength. The experimental results were specifically for a system consisting of Si3N4-WC/TiC/TaC bonded to Ni plate. The effects of the wedge angle of the metal side on residual stress near the interface edge were numerically predicted using FEM models. The interface wedge angles for this model, φ1 and φ2, were defined using the configuration angle between the interface and free surfaces of both materials. The numerical results showed that the stress σr on the free surface of the ceramic side was concentrated near the interface edge at which discontinuity in the stress state is generated. Dependence of the residual stress variation on both the wedge angle and temperature conditions can be predicted. It was confirmed that the bonding strength improves with decreasing residual stress in geometrical conditions. Therefore, residual stress appears to be a predominant factor affecting bonding strength. The observed fracture pattern showed that the fracture originated near the interface edges, after which small cracks propagated on the ceramic side. The residual stress is presumed to dominate bonding strength as the fracture occurred near the interface edge of the ceramic side. Results showed that the maximum bonding strength appears at the geometrical condition where the fracture pattern changes to φ2 lower than 90° of joint bonded at 980 °C. Therefore, the optimum interface wedge angle depends on a combination of materials and bonding temperature conditions, because the weak point of the bonded joint system will affect the stiffness balance of both materials and the adhesion power of the bonded interface.

Dependence of Bonding Strength of Ceramic to Metal Joint on Interface Wedge Angle in Metal Side

2012 ◽  
Author(s):  
Masayoshi Tateno ◽  
Eiichiro Yokoi
Keyword(s):  
Bonding Strength ◽  
Bonding Temperature ◽  
Wedge Angle ◽  
Fracture Pattern ◽  
Interface Condition ◽  
Geometrical Shape ◽  
Electric Discharge Machining ◽  
Bonded Materials ◽  
Edge Angle ◽  
Metal Joint

The focus of this study is to clarify a dependence of bonding strength of ceramic to metal joint on interface wedge angle in metal side. Each plate Si3N4-to-Cu or Ni joint with plane interface is produced by electric discharge machining. Geometrical shape at the edge of the interface is characterized by wedge angle defined as a configuration angle between free surface of each material and the interface. As the wedge angle of Si3N4 is right angle, the wedge angle of metal is set over from 30° to 180°. Each joint is bonded at high temperature by using thin braze metal under vacuum and slowly cooled. Tensile bonding strength of the joint is evaluated. Result shows that decrease of the wedge angle of metal side from right angle improves the bonding strength since it decreases the residual stress near edge of the interface on ceramic side. The highest bonding strength appears at the identical interface condition where fracture pattern changes. It appears that optimum edge angle for obtaining the highest bonding strength depends on bonding temperature and combination of bonded materials. This paper provides a useful geometrical interface shape to improve tensile bonding strength of ceramic to metal joint.

Bonding Temperature Condition Dependence of Strength Improvement Effect by Decrease of Metal Thickness in Ceramic to Metal Joint System

2016 ◽  
Author(s):  
Masayoshi Tateno ◽  
Takashi Tominaga
Keyword(s):  
Residual Stress ◽  
Metal Layer ◽  
Bonding Temperature ◽  
Thin Metal ◽  
Joint System ◽  
Temperature Conditions ◽  
Metal Thickness ◽  
Metal Joint ◽  
Two Stages ◽  
Secondary Bonding

This study provides effects of bonding temperature conditions on practical strength in ceramic to metal joint system made by two stages bonding process. Ceramic to metal joint system is required to reduce the residual stress near the edge of the interface and to improve bonding strength. The two stages bonding process, which was proposed in PVP2015-45822, can be a useful method to prevent the residual stress from increasing. This process consists of two stages, the first bonding process defined as a ceramic is bonded to thin metal layer at high temperature and the secondary process defined as a thick metal is bonded to the thin metal layer of the joint at lower temperature. It is necessary to provide effects of thickness of thin metal layer on the practical bonding strength in various combinations of the first and the secondary bonding temperature conditions. Past experimental results showed the practical bonding strength would be dominated by the residual stress near the edge of the interface between the thin metal layer and the ceramic. The residual stress can be associated with the first and/or the secondary bonding temperature conditions. Setting the optimum metal thickness improves the bonding strength independent of the bonding temperature conditions in the limited conditions. This paper provided dependence of the optimum metal layer thickness on the first and the secondary bonding temperature conditions was clarified experimentally. It also found effective metal thickness, which is capable of strengthening the siliconnitride to nickel joint system, in the combination of the first bonding temperature ranged over from 880°C to 980°C and the secondary bonding temperature ranged over from 600°C to 700°C. It appeared the first bonding temperature and the secondary one are set at the higher, the optimum metal thickness becomes smaller. The result showed that decreasing metal thickness possesses similar effect to decreasing bonding temperature for reducing the thermal residual stress. Reducing the residual stress is capable of strengthening the part of the edge of the interface on the ceramic side. Setting the metal layer thinner should be applied for producing the high strength ceramic to metal joint system. The two stages bonding process can contribute to achieve the high strength bonded dissimilar materials by setting the optimum thin metal thickness.

Effect of Interface Edge Shape on Bonding Strength in Ceramic to Metal Joint

2006 ◽  
Author(s):  
Masayoshi Tateno ◽  
Yohei Hatano ◽  
Kunio Kokubo
Keyword(s):  
Bonding Strength ◽  
Bonding Temperature ◽  
Dissimilar Materials ◽  
Fracture Pattern ◽  
Interface Condition ◽  
Optimum Shape ◽  
Edge Angle ◽  
Metal Joint ◽  
The Right ◽  
Interface Edge

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.

Dependence of Bonding Temperature Conditions on Metal Thickness Effects in Bonded Dissimilar Materials

2015 ◽  
Author(s):  
Masayoshi Tateno ◽  
Eiichiro Yokoi
Keyword(s):  
Residual Stress ◽  
Bonding Strength ◽  
Bonding Temperature ◽  
Dissimilar Materials ◽  
Bonding Process ◽  
Secondary Process ◽  
Material System ◽  
Temperature Conditions ◽  
Metal Thickness ◽  
Two Stages

This study provides information on the dependence of bonding temperature conditions on metal thickness effects in bonded dissimilar materials as a composite material system. Effects of metal thickness on the bonding strength were confirmed each bonding temperature condition by using silicon-nitride and nickel to confirm for each joint manufactured by a bonding method, two stages bonding process. This process used in this experiment consists of two stages, first bonding process as the ceramic is bonded to thin layer metal at high temperature, and secondary process as thick metal is bonded to the thin metal layer of the joint at lower temperature than first stage’s one. Bonding tensile strength of the joint specimen was evaluated experimentally. The bonding strength was dominated by the residual stress near the edge of the interface on ceramic side. The maximum bonding strength appears at optimum metal thickness. It shows that the optimum metal thickness depends on the first temperature condition. Reduction of the residual stress was considered based on the experimental and numerical results. Two stages bonding process can be applied for high strength bonded dissimilar materials as useful engineering application by setting optimum metal thickness each bonding temperature condition.

Effect of Interface Wedge Angle in Ceramic Side on Tensile Bonding Strength in Ceramic to Metal Joint

2009 ◽  
Author(s):  
Masayoshi Tateno ◽  
Hiroki Morikawa ◽  
Kunio Kokubo
Keyword(s):  
Free Surface ◽  
Bonding Strength ◽  
Bonding Temperature ◽  
Wedge Angle ◽  
Fracture Pattern ◽  
Interface Conditions ◽  
Interface Shape ◽  
Electric Discharge Machining ◽  
Side Plate ◽  
Metal Joint

This study was performed to clarify the dependence of ceramic-to-metal joint bonding strength on the interface wedge angle on the ceramic side. Plate Si3N4-to-Ni joints with a plane interface were produced by electric discharge machining. The geometric interface shape at the edge of the interface is characterized by wedge angle on both sides of the ceramic and metal defined as a configuration angle between the free surface of each material and the interface. As the wedge angle of Ni is a right angle, the wedge angle of Si3N4 is set from 30° to 180°. Joints were bonded at high temperature using thin braze metal under vacuum and cooled slowly. The tensile bonding strength of the ceramic-to-metal joint was evaluated to determine the optimum interface shape. The highest bonding strength appeared under identical interface conditions where the fracture pattern changed. The optimum wedge angle to obtain the greatest bonding strength appears to depend on bonding temperature. This study provided a useful geometric interface shape to improve the tensile bonding strength of ceramic-to-metal joints.

Effects of Interface Wedge Angle in Metal Side on Bonding Strength in Ceramic to Metal Joint

2011 ◽  
Author(s):  
Masayoshi Tateno ◽  
Eiichirou Yokoi
Keyword(s):  
Free Surface ◽  
High Temperature ◽  
Bonding Strength ◽  
Wedge Angle ◽  
Fracture Pattern ◽  
Interface Conditions ◽  
Interface Shape ◽  
Electric Discharge Machining ◽  
Metal Joint ◽  
Wire Electric Discharge Machining

This study was performed to clarify dependences of bonding strength on the interface wedge angle in the metal side of ceramic-to-metal joint. Each plate Si3N4 and Ni used for this experiment is produced by wire electric discharge machining. The geometric interface shape at the edge of the interface is characterized by wedge angle on both side of the ceramic and metal defined as a configuration angle between the free surface of each material and the interface. As the wedge angle of Si3N4 is a right angle, the wedge angle of Ni is set from 30° to 180°. Joint specimens were bonded at high temperature using braze metal of 0.05mm thickness under vacuum and cooled slowly. The tensile bonding strength of the ceramic-to-metal joint was evaluated to determine the optimum interface shape. The highest bonding strength appeared under identical interface conditions where the fracture pattern changed. This study provided a useful geometric interface shape to improve the tensile bonding strength of ceramic-to-metal joint.

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

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.

Design and Fabrication of a Magnetocaloric Microcooler

2005 ◽  
Author(s):  
Sangchae Kim ◽  
Bharath Bethala ◽  
Simone Ghirlanda ◽  
Senthil N. Sambandam ◽  
Shekhar Bhansali
Keyword(s):  
Magnetic Field ◽  
Ambient Temperature ◽  
Temperature Change ◽  
Entropy Change ◽  
Temperature Sensors ◽  
Experimental Results ◽  
Maximum Temperature ◽  
Alternative Technology ◽  
Temperature Conditions ◽  
Si Wafer

Magnetocaloric refrigeration is increasingly being explored as an alternative technology for cooling. This paper presents the design and fabrication of a micromachined magnetocaloric cooler. The cooler consists of fluidic microchannels (in a Si wafer), diffused temperature sensors, and a Gd5(Si2Ge2) magnetocaloric refrigeration element. A magnetic field of 1.5 T is applied using an electromagnet to change the entropy of the magnetocaloric element for different ambient temperature conditions ranging from 258 K to 280 K, and the results are discussed. The tests show a maximum temperature change of 7 K on the magnetocaloric element at 258 K. The experimental results co-relate well with the entropy change of the material.

Finite Element Modeling for Prediction of Residual Stresses in Fiber Reinforced Metal Matrix Composites

1993 ◽  
Author(s):  
Partha Rangaswamy ◽  
N. Jayaraman
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Matrix Material ◽  
Unit Cell ◽  
Experimental Results ◽  
Matrix Composites ◽  
Layer Removal

Abstract In metal matrix composites residual stresses developing during the cool-down process after consolidation due to mismatch in thermal expansion coefficients between the ceramic fibers and metal matrix have been predicted using finite element analysis. Conventionally, unit cell models consisting of a quarter fiber surrounded by the matrix material have been developed for analyzing this problem. Such models have successfully predicted the stresses at the fiber-matrix interface. However, experimental work to measure residual stresses have always been on surfaces far away from the interface region. In this paper, models based on the conventional unit cell (one quarter fiber), one fiber, two fibers have been analyzed. In addition, using the element birth/death options available in the FEM code, the surface layer removal process that is conventionally used in the residual stress measuring technique has been simulated in the model. Such layer removal technique allows us to determine the average surface residual stress after each layer is removed and a direct comparison with experimental results are therefore possible. The predictions are compared with experimental results of an eight-ply unidirectional composite with Ti-24Al-11 Nb as matrix material reinforced with SCS-6 fibers.

Weldability and machinability of the dissimilar joints of Ti alloy and stainless steel – A review

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yan Zhang ◽  
YuanBo Bi ◽  
JianPing Zhou ◽  
DaQian Sun ◽  
HongMei Li
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Bonding Temperature ◽  
Fusion Welding ◽  
Research Progress ◽  
Diffusion Welding ◽  
Ti Alloy ◽  
Dissimilar Joints ◽  
Advantages And Disadvantages ◽  
Fe Intermetallics

Abstract As two important industrial manufacturing materials, titanium alloys and stainless steel have their own advantages and disadvantages in terms of physical, chemical, and mechanical properties. The field of materials manufacturing has witnessed efforts to develop technical processes that can properly combine these two alloy types, aiming to effectively use their respective advantages. The welding technology for Ti alloy and stainless steel, as a research topic with broad prospects, is comprehensively and deeply analyzed in this review. The current research progress in this field was analyzed from different process perspectives such as fusion welding, brazing, diffusion welding, friction welding, explosive welding and vacuum hot-rolling welding. The results of the review showed that the greatest challenges of fusion welding are low ductility of the material, high residual stress, high cooling rate, and the formation of numerous brittle Ti-Fe intermetallics. By using appropriate intermediate materials between these two materials, the residual stress and brittle intermetallics near the interface of the transition joint can be minimised by solving the thermal expansion mismatch, reducing the bonding temperature and pressure, and suppressing the diffusion of elements such as Ti and Fe.

Sign in / Sign up

Export Citation Format

Share Document