Contact reactive brazing of 6063 Al alloy and 1Cr18Ni9Ti stainless steel was researched by using Cu as interlayer. Effect of brazing time on microstructure of the joints, as well as the dissolution behaviors of Cu int...Contact reactive brazing of 6063 Al alloy and 1Cr18Ni9Ti stainless steel was researched by using Cu as interlayer. Effect of brazing time on microstructure of the joints, as well as the dissolution behaviors of Cu interlayer was analyzed. The results show that the product of reaction zone near 1Cr18Ni9Ti is composed of Fe2Al5, FeAl3 intermetallic compound （IMC）, and Cu-Al IMC; the near by area is composed of Al-Cu eutectic structure with Al （Cu） solid solution. With increasing the brazing time, the thickness of IMC layer at the interface increases, while the width of Al-Cu eutectic structure with Al（Cu） solution decreases. Calculation shows the dissolution rate of Cu interlayer is very fast. The complete dissolution time is about 0.47 s for Cu interlayer with 10 μm in thickness used in this study.展开更多
The behavior of eutectic liquid penetrating into the Al base during Al/Cu contact reactive brazing process was studied. Analysis results show that the eutectic liquid prefers to expand along the grain boundary in the ...The behavior of eutectic liquid penetrating into the Al base during Al/Cu contact reactive brazing process was studied. Analysis results show that the eutectic liquid prefers to expand along the grain boundary in the depth direction. Meanwhile, dissolution of solid Al and Cu into the eutectic liquid promotes the eutectic reaction and the continuously formed eutectic liquid leads to the reactive penetrating.展开更多
The surface tensions and contact angles of Fe_(78)Si_9B_(13) and Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 alloy melts were studied as a function of temperature in various atmospheres(vacuum, Ar and N_2 gas) and on different subs...The surface tensions and contact angles of Fe_(78)Si_9B_(13) and Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 alloy melts were studied as a function of temperature in various atmospheres(vacuum, Ar and N_2 gas) and on different substrates(Si C, Al_2O_3 and BN). It is indicated that Si_3N_4, NbN, Fe_2 Al B and B_(13)C_2 are generated as new phases at the interface between the melt and substrate, and reactive wetting behaviour exists during the heating process. The surface tensions of two alloy melts on BN substrate both firstly decrease and then increase along with increasing temperature, leading to V-shaped surface tension versus temperature, which results from atomic diffusion effects in the surface layer during the oxidation of BN and formation of C-rich layer. Comparably, the surface tensions on Al_2O_3 and Si C substrates decrease with increasing temperature throughout the entire temperature range. Among three substrates, BN exhibits the mildest wetting behaviour. The vacuum environment has the strongest protective effect on melt stability among the tested atmospheres. These findings enrich our knowledge about the effects of the substrate and atmosphere on Fe-based alloy melts at a high temperature, and provide theoretical reference for designing jet nozzles in melt-spinning techniques.展开更多
文摘Contact reactive brazing of 6063 Al alloy and 1Cr18Ni9Ti stainless steel was researched by using Cu as interlayer. Effect of brazing time on microstructure of the joints, as well as the dissolution behaviors of Cu interlayer was analyzed. The results show that the product of reaction zone near 1Cr18Ni9Ti is composed of Fe2Al5, FeAl3 intermetallic compound （IMC）, and Cu-Al IMC; the near by area is composed of Al-Cu eutectic structure with Al （Cu） solid solution. With increasing the brazing time, the thickness of IMC layer at the interface increases, while the width of Al-Cu eutectic structure with Al（Cu） solution decreases. Calculation shows the dissolution rate of Cu interlayer is very fast. The complete dissolution time is about 0.47 s for Cu interlayer with 10 μm in thickness used in this study.
文摘The behavior of eutectic liquid penetrating into the Al base during Al/Cu contact reactive brazing process was studied. Analysis results show that the eutectic liquid prefers to expand along the grain boundary in the depth direction. Meanwhile, dissolution of solid Al and Cu into the eutectic liquid promotes the eutectic reaction and the continuously formed eutectic liquid leads to the reactive penetrating.
基金supported by the National Natural Science Foundation of China(Grant No.51501043)National Scientific and Technological Support Projects(Grant No.2013BAE08B00)+1 种基金National Key Scientific Instrument and Equiment Development Project(Grant No.2014YQ120351)Science and Technology Program of Beijing(Grant No.Z141100003814007)
文摘The surface tensions and contact angles of Fe_(78)Si_9B_(13) and Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 alloy melts were studied as a function of temperature in various atmospheres(vacuum, Ar and N_2 gas) and on different substrates(Si C, Al_2O_3 and BN). It is indicated that Si_3N_4, NbN, Fe_2 Al B and B_(13)C_2 are generated as new phases at the interface between the melt and substrate, and reactive wetting behaviour exists during the heating process. The surface tensions of two alloy melts on BN substrate both firstly decrease and then increase along with increasing temperature, leading to V-shaped surface tension versus temperature, which results from atomic diffusion effects in the surface layer during the oxidation of BN and formation of C-rich layer. Comparably, the surface tensions on Al_2O_3 and Si C substrates decrease with increasing temperature throughout the entire temperature range. Among three substrates, BN exhibits the mildest wetting behaviour. The vacuum environment has the strongest protective effect on melt stability among the tested atmospheres. These findings enrich our knowledge about the effects of the substrate and atmosphere on Fe-based alloy melts at a high temperature, and provide theoretical reference for designing jet nozzles in melt-spinning techniques.
