Ti-47Al-2Nb-2Cr-0.15B(mole fraction,%)alloy was vacuum brazed with amorphous and crystalline Ti.25Zr-12.5Cu-12.5Ni-3.0Co-2.0Mo(mass fraction,%)filler alloys,and the melting,spreading and gap filling behaviors of the a...Ti-47Al-2Nb-2Cr-0.15B(mole fraction,%)alloy was vacuum brazed with amorphous and crystalline Ti.25Zr-12.5Cu-12.5Ni-3.0Co-2.0Mo(mass fraction,%)filler alloys,and the melting,spreading and gap filling behaviors of the amorphous and crystalline filler alloys as well as the joints brazed with them were investigated in details.Results showed that the amorphous filler alloy possessed narrower melting temperature interval,lower liquidus temperature and melting active energy compared with the crystalline filler alloy,and it also exhibited better brazeability on the surface of the Ti.47Al.2Nb.2Cr.0.15B alloy.The TiAl joints brazed with crystalline and amorphous filler alloys were composed of two interfacial reaction layers and a central brazed layer.Under the same conditions,the tensile strength of the joint brazed with the amorphous filler alloy was always higher than that with the crystalline filler alloy.The maxmium tensile strength of the joint brazed at 1273 K with the amorphous filler alloy reached 254 MPa.展开更多
Finite element analysis has been carried out to understand the effect of various processing routes and condition on the microscale deformation behavior of Al–4.5 Cu–2 Mg alloy. The alloy has been developed through f...Finite element analysis has been carried out to understand the effect of various processing routes and condition on the microscale deformation behavior of Al–4.5 Cu–2 Mg alloy. The alloy has been developed through four different routes and condition, i.e. conventional gravity casting with and without refiner, rheocasting and SIMA process. The optical microstructures of the alloy have been used to develop representative volume elements（RVEs）. Two different boundary conditions have been employed to simulate the deformation behavior of the alloy under uniaxial loading. Finally, the simulated stress-strain behavior of the alloy is compared with the experimental result. It is found that the microstructural morphology has a significant impact on stress and strain distribution and load carrying capacity. The eutectic phase always carries a higher load than the α（Al） phase. The globular α（Al） grains with thinner and uniformly distributed eutectic network provide a better stress and strain distribution. Owing to this, SIMA processed alloy has better stress and strain distribution than other processes. Finally, the simulated yield strength of the alloy is verified by experiment and they have great agreement.展开更多
Al-4. 5Cu-5Pb alloy was prepared by sand and chill casting. The same alloy was also spray deposited at a gas pressure of 1.6 MPa. The microstructural features exhibit a coarse to fine dendritic morphology for sand ...Al-4. 5Cu-5Pb alloy was prepared by sand and chill casting. The same alloy was also spray deposited at a gas pressure of 1.6 MPa. The microstructural features exhibit a coarse to fine dendritic morphology for sand and chill cast alloys. Equiaxed grains were observed for spray formed alloys. Wear testing employing a pin-on-disc type set-up, reveals considerably lower wear of spray deposited alloy compared to that of chill and sand cast alloys. The morphological features of wear track on specimen and debris indicated a mixed oxidative-cum-adhesive wear mechanisms for these alloys tested in the present investigation. (Edited author abstract) 36 Refs.展开更多
In this research the effect of cerium dopingon corrosion behavior of Ni-10 Cu-11 Fe-6 Al(wt%) alloy as a novel inert anode in titanium electrolytic production was investigated. The samples, including un-doped and Ce-d...In this research the effect of cerium dopingon corrosion behavior of Ni-10 Cu-11 Fe-6 Al(wt%) alloy as a novel inert anode in titanium electrolytic production was investigated. The samples, including un-doped and Ce-doped nickel-based alloys, were prepared using vacuum induction melting(VIM) process and then exposed to the electrolysis in molten calcium chloride at 900C at à1.6 V versus graphite reference electrode for different immersion time. The surface and cross-section of the samples were characterized using scanning electron microscopy(SEM), and their electrochemical behavior was investigated by electrochemical impedance spectroscopy(EIS). The results show that the un-doped samples have greater number of voids and porosities as compared to that of the 0.0064 wt% Ce-doped samples(as the optimum content of cerium in the alloy). Thus, the nickel-based alloy becomes less sensitive to the pitting by addition of cerium. The corrosion penetration depth reaches about 244 mm after 16 h of electrolysis in the un-doped sample, while was approximately 103 mm for the 0.0064 wt% Ce-doped sample, which is an indication that the corrosion penetration depth decreases by adding small amounts of Ce.展开更多
基金Foundation item:Project(51865012)supported by the National Natural Science Foundation of ChinaProject(2016005)supported by the Open Foundation of National Engineering Research Center of Near-net-shape Forming for Metallic Materials,China+2 种基金Project(GJJ170372)supported by the Science Foundation of Educational Department of Jiangxi Province,ChinaProject(JCKY2016603C003)supported by the GF Basic Research Project,ChinaProject(JPPT125GH038)supported by the Research Project of Special Furnishment and Part,China
文摘Ti-47Al-2Nb-2Cr-0.15B(mole fraction,%)alloy was vacuum brazed with amorphous and crystalline Ti.25Zr-12.5Cu-12.5Ni-3.0Co-2.0Mo(mass fraction,%)filler alloys,and the melting,spreading and gap filling behaviors of the amorphous and crystalline filler alloys as well as the joints brazed with them were investigated in details.Results showed that the amorphous filler alloy possessed narrower melting temperature interval,lower liquidus temperature and melting active energy compared with the crystalline filler alloy,and it also exhibited better brazeability on the surface of the Ti.47Al.2Nb.2Cr.0.15B alloy.The TiAl joints brazed with crystalline and amorphous filler alloys were composed of two interfacial reaction layers and a central brazed layer.Under the same conditions,the tensile strength of the joint brazed with the amorphous filler alloy was always higher than that with the crystalline filler alloy.The maxmium tensile strength of the joint brazed at 1273 K with the amorphous filler alloy reached 254 MPa.
文摘Finite element analysis has been carried out to understand the effect of various processing routes and condition on the microscale deformation behavior of Al–4.5 Cu–2 Mg alloy. The alloy has been developed through four different routes and condition, i.e. conventional gravity casting with and without refiner, rheocasting and SIMA process. The optical microstructures of the alloy have been used to develop representative volume elements（RVEs）. Two different boundary conditions have been employed to simulate the deformation behavior of the alloy under uniaxial loading. Finally, the simulated stress-strain behavior of the alloy is compared with the experimental result. It is found that the microstructural morphology has a significant impact on stress and strain distribution and load carrying capacity. The eutectic phase always carries a higher load than the α（Al） phase. The globular α（Al） grains with thinner and uniformly distributed eutectic network provide a better stress and strain distribution. Owing to this, SIMA processed alloy has better stress and strain distribution than other processes. Finally, the simulated yield strength of the alloy is verified by experiment and they have great agreement.
文摘Al-4. 5Cu-5Pb alloy was prepared by sand and chill casting. The same alloy was also spray deposited at a gas pressure of 1.6 MPa. The microstructural features exhibit a coarse to fine dendritic morphology for sand and chill cast alloys. Equiaxed grains were observed for spray formed alloys. Wear testing employing a pin-on-disc type set-up, reveals considerably lower wear of spray deposited alloy compared to that of chill and sand cast alloys. The morphological features of wear track on specimen and debris indicated a mixed oxidative-cum-adhesive wear mechanisms for these alloys tested in the present investigation. (Edited author abstract) 36 Refs.
文摘In this research the effect of cerium dopingon corrosion behavior of Ni-10 Cu-11 Fe-6 Al(wt%) alloy as a novel inert anode in titanium electrolytic production was investigated. The samples, including un-doped and Ce-doped nickel-based alloys, were prepared using vacuum induction melting(VIM) process and then exposed to the electrolysis in molten calcium chloride at 900C at à1.6 V versus graphite reference electrode for different immersion time. The surface and cross-section of the samples were characterized using scanning electron microscopy(SEM), and their electrochemical behavior was investigated by electrochemical impedance spectroscopy(EIS). The results show that the un-doped samples have greater number of voids and porosities as compared to that of the 0.0064 wt% Ce-doped samples(as the optimum content of cerium in the alloy). Thus, the nickel-based alloy becomes less sensitive to the pitting by addition of cerium. The corrosion penetration depth reaches about 244 mm after 16 h of electrolysis in the un-doped sample, while was approximately 103 mm for the 0.0064 wt% Ce-doped sample, which is an indication that the corrosion penetration depth decreases by adding small amounts of Ce.
