The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Ji Cai Feng - One of the best experts on this subject based on the ideXlab platform.
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Vacuum Brazing high Nb-containing TiAl Alloy to Ti60 Alloy using Ti-28Ni eutectic Brazing Alloy
Journal of Alloys and Compounds, 2017Co-Authors: Xiaoguo Song, Ji Cai Feng, Boyi Ben, Shengpeng Hu, Dongyan TangAbstract:High Nb-containing TiAl Alloy and Ti60 Alloy was brazed successfully by vacuum Brazing using Ti-28Ni eutectic Brazing Alloy. The effect of Brazing temperature on interfacial microstructure and mechanical properties of the joints was investigated. The interfacial microstructure of the joint brazed at low temperature was Ti60 substrate/Lamellar (α+β) microstructure/Ti2Ni phase layer + α-Ti/α-Ti layer + Ti2Ni/Ti3Al layer/B2 phase layer/TAN substrate, and the presence of Ti2Ni phase in the joints deteriorated the joining properties. The increasing Brazing temperature accelerated the diffusion of Ni atoms into the substrates, leading to the disappearance of Ti2Ni and Ti3Al phase and the growth of B2 phase. The maximum joining strength of ∼140 MPa was obtained when Brazing at 1080 °C for 10 min.
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Vacuum Brazing of TZM Alloy to ZrC particle reinforced W composite using Ti-28Ni eutectic Brazing Alloy
International Journal of Refractory Metals and Hard Materials, 2017Co-Authors: G. H. Han, X.g. Song, Y. F. Wang, H Y Zhao, J. Cao, Ji Cai FengAbstract:Reliable Brazing of TZM Alloy and ZrC particle reinforced (ZrCp) W composite was achieved in this study by using Ti-28Ni eutectic Brazing Alloy. The typical interfacial microstructure of TZM/Ti-28Ni/ZrCp-W brazed joint consisted of a Ti solid solution (Ti(s, s)) layer, a continuous Ti2Ni layer and a diffusion layer mainly composed of W particles and (Ti, Zr)C particles. With an increase of Brazing temperature, more ZrC particles and W particles entered the molten Brazing Alloy, which broadened the Brazing seam and diminished the Ti2Ni layer, resulting in the disappearance of the Ti2Ni layer eventually. Meanwhile, more Ti(s, s) stripes were observed on the TZM side. The presence of continuous Ti2Ni intermetallic phase and Ti(s, s) stripes structure in joints deteriorated the joining properties, which resulted in the formation of brittle fracture under shear test. In addition, the fracture path was related to the Brazing temperature, and cracks initiate and propagate in the continuous Ti2Ni layer at lower temperatures. However, the fracture path tended to be located at the TZM substrate close to the interface between TZM and the Brazing seam when the Brazing temperature exceeded 1040 °C. The optimal room temperature shear strength reached 120.5 MPa when brazed at 1040 °C for 10 min and the fracture surface exhibited cleavage fracture characteristics, and the shear strength at high temperature of 800 °C for the specimens with highest shear strength at room temperature reached 77.5 MPa.
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Joining of SiO2–BN ceramic to Nb using a CNT-reinforced Brazing Alloy
RSC Advances, 2014Co-Authors: Jing Huang Lin, Yu Han Wan, Lixia Zhang, Jian Cao, Ji Cai FengAbstract:Brazing SiO2–BN ceramics with Nb are often associated with the problems of high residual stress caused by the difference in the thermal expansion coefficients and poor mechanical properties under high temperature. To overcome these problems, here we report a new type of carbon nanotube (CNT)-reinforced TiNi Brazing Alloy via an “in situ growth” method by PECVD. The CNT/TiNi Brazing Alloy has very homogeneously dispersed CNTs within the TiNi Brazing Alloy, produced by in situ growth of CNTs on TiH2 and Ni powders mixed evenly into the CNT/TiH2 powders. It can be applied in the Brazing of SiO2–BN and Nb. Results show that the addition of CNTs into the TiNi Brazing Alloy is very beneficial for the dissolution and diffusion of Nb in the brazed joint, because it can promote more TiNi–(Nb,Ti) eutectics which emerge in most of the Brazing seam. Furthermore, the average shear strength of the brazed joint at room temperature is raised from 49 to 85 MPa with 1.5 vol% CNTs added into the TiNi Brazing Alloy. In particular, at 800 °C the brazed joint still has a very high shear strength of 51 MPa, about 1.7 times stronger than that of the TiNi Brazing Alloy. These results suggest that the CNTs played a key role in reducing the residual stress and reinforcing the mechanical properties (at both room and high temperature) of the brazed joint. It provides a way for the development of CNT-reinforced Brazing Alloys.
Dongyan Tang - One of the best experts on this subject based on the ideXlab platform.
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Vacuum Brazing high Nb-containing TiAl Alloy to Ti60 Alloy using Ti-28Ni eutectic Brazing Alloy
Journal of Alloys and Compounds, 2017Co-Authors: Xiaoguo Song, Ji Cai Feng, Boyi Ben, Shengpeng Hu, Dongyan TangAbstract:High Nb-containing TiAl Alloy and Ti60 Alloy was brazed successfully by vacuum Brazing using Ti-28Ni eutectic Brazing Alloy. The effect of Brazing temperature on interfacial microstructure and mechanical properties of the joints was investigated. The interfacial microstructure of the joint brazed at low temperature was Ti60 substrate/Lamellar (α+β) microstructure/Ti2Ni phase layer + α-Ti/α-Ti layer + Ti2Ni/Ti3Al layer/B2 phase layer/TAN substrate, and the presence of Ti2Ni phase in the joints deteriorated the joining properties. The increasing Brazing temperature accelerated the diffusion of Ni atoms into the substrates, leading to the disappearance of Ti2Ni and Ti3Al phase and the growth of B2 phase. The maximum joining strength of ∼140 MPa was obtained when Brazing at 1080 °C for 10 min.
Xin-rui Song - One of the best experts on this subject based on the ideXlab platform.
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Brazing of c c composites to ti6al4v using graphene nanoplatelets reinforced ticuzrni Brazing Alloy
Materials Letters, 2016Co-Authors: Xin-rui Song, Xierong Zeng, Leilei ZhangAbstract:Abstract Graphene nanoplatelets (GNPs) were used as reinforcement in the TiCuZrNi Brazing Alloy for joining carbon/carbon composites (C/C) to Ti6Al4V. The microstructure and fracture behavior of bonded joints were investigated. The results showed that the shear strength of C/C-Ti6Al4V joints with GNPs was much higher than that of the joints without GNPS. The improvement of shear strength was mainly caused by the fact that the existence of TiC particles and GNPS in braze, which could reduce the CTE of Brazing Alloy and alleviate the residual stresses at the interface of C/C and braze.
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Brazing of C/C composites to Ti6Al4V using multiwall carbon nanotubes reinforced TiCuZrNi Brazing Alloy
Journal of Alloys and Compounds, 2016Co-Authors: Xin-rui Song, Xierong ZengAbstract:Abstract Carbon nanotubes (CNTs) were used as reinforcements in the TiCuZrNi Brazing Alloy for joining C/C composites to Ti6Al4V. The effects of CNTs content on the shear strength and microstructure of brazed joints were investigated. The CNTs react with Ti element from the Brazing Alloy, forming TiC particles in situ during the Brazing process. The apparent shear strength of the joints is 38 ± 2 MPa using 1 wt.% CNTs in TiCuZrNi Brazing Alloy, which is 73% higher than that of the joints without CNTs. An improvement of the mechanical properties was ascribed to the in situ formation of TiC particles which induced the reinforced effects such as crack deflection, interface debonding and particle fracture. When the CNTs content in the Brazing Alloy increased to 3 wt.%, the joints strength dramatically decreased. This is the result of the insufficient reaction between the C/C composites and the braze. Moreover, the high content of CNTs make negative effects on the wettability and penetrability of the Brazing Alloy.
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microstructure and mechanical properties of c c composite ti6al4v joints with a cu ticuzrni composite Brazing Alloy
Ceramics International, 2016Co-Authors: Xin-rui Song, Valentina Casalegno, Milena Salvo, Monica Ferraris, Xierong ZengAbstract:Abstract C/C composites and Ti 6 Al 4 V sheets were joined using a novel Cu/TiCuZrNi composite braze and the effect of Cu foil thickness on the microstructure and mechanical properties of the joints were investigated. A composite joining material, consisting of a TiC particle reinforced Brazing Alloy formed in situ during the Brazing process was obtained. Before the joining process, the C/C composite surface was modified by solid state reaction with chromium to form a chromium carbide coating. This carbide reaction layer can react with the Ti-based Brazing Alloy and form evenly distributed TiC particles. The maximum apparent shear strength of as-received joint was 39±8.5 MPa obtained by using a 40 μm thick Cu foil together with the TiCuZrNi Alloy; this value was 70% higher than the mechanical strength obtained for joints brazed with the TiCuZrNi Alloy only.
Xierong Zeng - One of the best experts on this subject based on the ideXlab platform.
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Brazing of c c composites to ti6al4v using graphene nanoplatelets reinforced ticuzrni Brazing Alloy
Materials Letters, 2016Co-Authors: Xin-rui Song, Xierong Zeng, Leilei ZhangAbstract:Abstract Graphene nanoplatelets (GNPs) were used as reinforcement in the TiCuZrNi Brazing Alloy for joining carbon/carbon composites (C/C) to Ti6Al4V. The microstructure and fracture behavior of bonded joints were investigated. The results showed that the shear strength of C/C-Ti6Al4V joints with GNPs was much higher than that of the joints without GNPS. The improvement of shear strength was mainly caused by the fact that the existence of TiC particles and GNPS in braze, which could reduce the CTE of Brazing Alloy and alleviate the residual stresses at the interface of C/C and braze.
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Brazing of C/C composites to Ti6Al4V using multiwall carbon nanotubes reinforced TiCuZrNi Brazing Alloy
Journal of Alloys and Compounds, 2016Co-Authors: Xin-rui Song, Xierong ZengAbstract:Abstract Carbon nanotubes (CNTs) were used as reinforcements in the TiCuZrNi Brazing Alloy for joining C/C composites to Ti6Al4V. The effects of CNTs content on the shear strength and microstructure of brazed joints were investigated. The CNTs react with Ti element from the Brazing Alloy, forming TiC particles in situ during the Brazing process. The apparent shear strength of the joints is 38 ± 2 MPa using 1 wt.% CNTs in TiCuZrNi Brazing Alloy, which is 73% higher than that of the joints without CNTs. An improvement of the mechanical properties was ascribed to the in situ formation of TiC particles which induced the reinforced effects such as crack deflection, interface debonding and particle fracture. When the CNTs content in the Brazing Alloy increased to 3 wt.%, the joints strength dramatically decreased. This is the result of the insufficient reaction between the C/C composites and the braze. Moreover, the high content of CNTs make negative effects on the wettability and penetrability of the Brazing Alloy.
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microstructure and mechanical properties of c c composite ti6al4v joints with a cu ticuzrni composite Brazing Alloy
Ceramics International, 2016Co-Authors: Xin-rui Song, Valentina Casalegno, Milena Salvo, Monica Ferraris, Xierong ZengAbstract:Abstract C/C composites and Ti 6 Al 4 V sheets were joined using a novel Cu/TiCuZrNi composite braze and the effect of Cu foil thickness on the microstructure and mechanical properties of the joints were investigated. A composite joining material, consisting of a TiC particle reinforced Brazing Alloy formed in situ during the Brazing process was obtained. Before the joining process, the C/C composite surface was modified by solid state reaction with chromium to form a chromium carbide coating. This carbide reaction layer can react with the Ti-based Brazing Alloy and form evenly distributed TiC particles. The maximum apparent shear strength of as-received joint was 39±8.5 MPa obtained by using a 40 μm thick Cu foil together with the TiCuZrNi Alloy; this value was 70% higher than the mechanical strength obtained for joints brazed with the TiCuZrNi Alloy only.
Xiaoguo Song - One of the best experts on this subject based on the ideXlab platform.
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Vacuum Brazing high Nb-containing TiAl Alloy to Ti60 Alloy using Ti-28Ni eutectic Brazing Alloy
Journal of Alloys and Compounds, 2017Co-Authors: Xiaoguo Song, Ji Cai Feng, Boyi Ben, Shengpeng Hu, Dongyan TangAbstract:High Nb-containing TiAl Alloy and Ti60 Alloy was brazed successfully by vacuum Brazing using Ti-28Ni eutectic Brazing Alloy. The effect of Brazing temperature on interfacial microstructure and mechanical properties of the joints was investigated. The interfacial microstructure of the joint brazed at low temperature was Ti60 substrate/Lamellar (α+β) microstructure/Ti2Ni phase layer + α-Ti/α-Ti layer + Ti2Ni/Ti3Al layer/B2 phase layer/TAN substrate, and the presence of Ti2Ni phase in the joints deteriorated the joining properties. The increasing Brazing temperature accelerated the diffusion of Ni atoms into the substrates, leading to the disappearance of Ti2Ni and Ti3Al phase and the growth of B2 phase. The maximum joining strength of ∼140 MPa was obtained when Brazing at 1080 °C for 10 min.