Recently,the presentation of the metal-ceramic composite structure design provides an alternative idea for the improvement of components service performance,while conventional methods for joining metals and ceramics h...Recently,the presentation of the metal-ceramic composite structure design provides an alternative idea for the improvement of components service performance,while conventional methods for joining metals and ceramics have to involve a high heat input.However,due to the low melting point of magnesium alloys,the magnesium alloys-ceramics joining system necessitates a low joining temperature.Ultrasonic vibrations can induce numerous defects in the solid matrix,which can effectively promote atomic diffusion and metallurgical bonding between solid-phase interfaces at low temperatures.Thus,ultrasonic-assisted bonding is a highly promising method for achieving rapid and reliable joining between metals and ceramics without the use of interlayers.In this study,the direct bonding of AZ31B alloy with ZrO_(2) ceramic was successfully achieved at 200℃.A polycrystal spinel MgAl_(2)O_(4) with an average thickness of 55 nm was identified at the AZ31B/ZrO_(2) interface.The average shear strength of joints reached 30.47 MPa.Furthermore,the dynamic recrystallization of AZ31B and the oxygendepletion behavior of ZrO_(2) during the bonding process were characterized to illustrate the contribution of ultrasonic vibration to joint bonding.Consequently,the solid interfacial sono-oxidation reaction is proposed to discuss the bonding mechanism of the joint in detail.展开更多
A bonding approach based on laser surface modification was developed to address the poor bonding be-tween Si_(3)N_(4) ceramic and Cu.The bonding mechanism in Si_(3)N_(4)/Cu heterogeneous composite structure fabricated...A bonding approach based on laser surface modification was developed to address the poor bonding be-tween Si_(3)N_(4) ceramic and Cu.The bonding mechanism in Si_(3)N_(4)/Cu heterogeneous composite structure fabricated by laser modification-assisted bonding is examined by means of scanning/transmission elec-tron microscopy and thermodynamic analysis.In the bonding process under laser modification,atomic intermixing at the interface is confirmed,as a result of the enhanced diffusion assisted by the dissocia-tion of Si_(3)N_(4) ceramic by laser.The dissociating Si precipitations on the surface,as well as the formation of micro-pores interfacial structure,would be the key concept of the bonding,by which the seamless and robust heterointerfaces were created.By controlling the laser-modifying conditions,we can obtain a reli-able heterostructure via the optimization of the trade-off of the surface structure and bonding strength,as determined by the laser-modified surface prior to bonding.The maximum structure depth and S ratio at the Si_(3)N_(4) surface were produced at a laser power of 56 W,corresponding to the maximal shear strength of 15.26 MPa.It is believed that the further development of this bonding technology will advance power electronic substrate fabrication applied in high-power devices.展开更多
基金supported by the Shandong Provincial Natural Science Foundation(ZR2023ME111).
文摘Recently,the presentation of the metal-ceramic composite structure design provides an alternative idea for the improvement of components service performance,while conventional methods for joining metals and ceramics have to involve a high heat input.However,due to the low melting point of magnesium alloys,the magnesium alloys-ceramics joining system necessitates a low joining temperature.Ultrasonic vibrations can induce numerous defects in the solid matrix,which can effectively promote atomic diffusion and metallurgical bonding between solid-phase interfaces at low temperatures.Thus,ultrasonic-assisted bonding is a highly promising method for achieving rapid and reliable joining between metals and ceramics without the use of interlayers.In this study,the direct bonding of AZ31B alloy with ZrO_(2) ceramic was successfully achieved at 200℃.A polycrystal spinel MgAl_(2)O_(4) with an average thickness of 55 nm was identified at the AZ31B/ZrO_(2) interface.The average shear strength of joints reached 30.47 MPa.Furthermore,the dynamic recrystallization of AZ31B and the oxygendepletion behavior of ZrO_(2) during the bonding process were characterized to illustrate the contribution of ultrasonic vibration to joint bonding.Consequently,the solid interfacial sono-oxidation reaction is proposed to discuss the bonding mechanism of the joint in detail.
基金supported by the National Natural Science Foun-dation of China(grant Nos.52275318 and 52175307)Taishan Scholars Foundation of Shandong Province(No.tsqn201812128)+1 种基金Shandong Natural Science Foundation(Nos.ZR2023JQ021 and ZR2023QE221)China Academy of Space Technology Innovation Foundation(No.CAST2022).
文摘A bonding approach based on laser surface modification was developed to address the poor bonding be-tween Si_(3)N_(4) ceramic and Cu.The bonding mechanism in Si_(3)N_(4)/Cu heterogeneous composite structure fabricated by laser modification-assisted bonding is examined by means of scanning/transmission elec-tron microscopy and thermodynamic analysis.In the bonding process under laser modification,atomic intermixing at the interface is confirmed,as a result of the enhanced diffusion assisted by the dissocia-tion of Si_(3)N_(4) ceramic by laser.The dissociating Si precipitations on the surface,as well as the formation of micro-pores interfacial structure,would be the key concept of the bonding,by which the seamless and robust heterointerfaces were created.By controlling the laser-modifying conditions,we can obtain a reli-able heterostructure via the optimization of the trade-off of the surface structure and bonding strength,as determined by the laser-modified surface prior to bonding.The maximum structure depth and S ratio at the Si_(3)N_(4) surface were produced at a laser power of 56 W,corresponding to the maximal shear strength of 15.26 MPa.It is believed that the further development of this bonding technology will advance power electronic substrate fabrication applied in high-power devices.
