Ag-Cu-In-Ti low-temperature filler was used to braze the diamond and copper,and the effects of brazing temperature and soaking time on the microstructure and mechanical properties of the joints were investigated.In ad...Ag-Cu-In-Ti low-temperature filler was used to braze the diamond and copper,and the effects of brazing temperature and soaking time on the microstructure and mechanical properties of the joints were investigated.In addition,the joint formation mechanism was discussed,and the correlation between joint microstructure and mechanical performance was established.Results show that adding appropriate amount of In into the filler can significantly reduce the filler melting point and enhance the wettability of filler on diamond.When the brazing temperature is 750°C and the soaking time is 10 min,a uniformly dense braze seam with excellent metallurgical bonding can be obtained,and its average joint shear strength reaches 322 MPa.The lower brazing temperature can mitigate the risk of diamond graphitization and also reduce the residual stresses during joining.展开更多
Sintered metals serving as thermal interface materials(TIMs)with superior thermal conductivities show the most promise in meeting the heat dissipation requirements of next-generation wide bandgap applications.Neverthe...Sintered metals serving as thermal interface materials(TIMs)with superior thermal conductivities show the most promise in meeting the heat dissipation requirements of next-generation wide bandgap applications.Nevertheless,their thermal stabilities during high-temperature service provide significant challenges.Herein,a facile approach was developed for one-step synthesis of single-phase Ag-Cu supersaturated solid-solution nanoparticle(Ag-Cu SS-NP)pastes with adjustable Cu contents(up to 37.7 at.%),and they exhibited ultrahigh resistance to oxidation and excellent sinterability.A paste composed of Ag-Cu SS-NPs was sintered in air at 250℃ for 20 min,and this resulted in a dense supersaturated structure with an impressive thermal conductivity of 157.8 W/(m K)and a room-temperature shear strength of 133.4 MPa.Microstructural analyses demonstrated that Cu had precipitated from the Ag lattice to form Cu nanoprecipitates,which refined the grain sizes and induced high-density dislocations during sintering.For the pinning effect of dislocations and grain boundaries by the Cu nanoprecipitates and coherent twins,the high-temperature(400℃)shear strength of sintered Ag-Cu SS-NP joints was significantly improved by 67%(58.6 MPa),meanwhile the shear strength after long-term aging at 200 and 300℃for 960 h were increased by 123%(140.3 MPa)and 80%(82.4 MPa)compared to those of sintered Ag NP joints,respectively.The remarkable thermal stability is far superior to traditional TIMs,so the Ag-Cu SS-NP paste exhibits excellent potential as a TIM for high-temperature power device applications.展开更多
基金National MCF Energy R&D Program(2019YFE03100400)。
文摘Ag-Cu-In-Ti low-temperature filler was used to braze the diamond and copper,and the effects of brazing temperature and soaking time on the microstructure and mechanical properties of the joints were investigated.In addition,the joint formation mechanism was discussed,and the correlation between joint microstructure and mechanical performance was established.Results show that adding appropriate amount of In into the filler can significantly reduce the filler melting point and enhance the wettability of filler on diamond.When the brazing temperature is 750°C and the soaking time is 10 min,a uniformly dense braze seam with excellent metallurgical bonding can be obtained,and its average joint shear strength reaches 322 MPa.The lower brazing temperature can mitigate the risk of diamond graphitization and also reduce the residual stresses during joining.
基金supported by the National Natural Science Foundation of China(Nos.52075125 and 52105331)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515010591)the Shenzhen Science and Technology Innovation Committee(Nos.JCYJ20210324124203009,JSGG20201102154600003,GXWD20231130103814001,and GXWD20220721182229001).
文摘Sintered metals serving as thermal interface materials(TIMs)with superior thermal conductivities show the most promise in meeting the heat dissipation requirements of next-generation wide bandgap applications.Nevertheless,their thermal stabilities during high-temperature service provide significant challenges.Herein,a facile approach was developed for one-step synthesis of single-phase Ag-Cu supersaturated solid-solution nanoparticle(Ag-Cu SS-NP)pastes with adjustable Cu contents(up to 37.7 at.%),and they exhibited ultrahigh resistance to oxidation and excellent sinterability.A paste composed of Ag-Cu SS-NPs was sintered in air at 250℃ for 20 min,and this resulted in a dense supersaturated structure with an impressive thermal conductivity of 157.8 W/(m K)and a room-temperature shear strength of 133.4 MPa.Microstructural analyses demonstrated that Cu had precipitated from the Ag lattice to form Cu nanoprecipitates,which refined the grain sizes and induced high-density dislocations during sintering.For the pinning effect of dislocations and grain boundaries by the Cu nanoprecipitates and coherent twins,the high-temperature(400℃)shear strength of sintered Ag-Cu SS-NP joints was significantly improved by 67%(58.6 MPa),meanwhile the shear strength after long-term aging at 200 and 300℃for 960 h were increased by 123%(140.3 MPa)and 80%(82.4 MPa)compared to those of sintered Ag NP joints,respectively.The remarkable thermal stability is far superior to traditional TIMs,so the Ag-Cu SS-NP paste exhibits excellent potential as a TIM for high-temperature power device applications.
