In this investigation, the Gleeble 1500 test simulator was used for carrying out experiments of joining by the pressurized combustion synthesis (PCS). The intermetallic compound Ni3Al was bonded by us- ing the exothe...In this investigation, the Gleeble 1500 test simulator was used for carrying out experiments of joining by the pressurized combustion synthesis (PCS). The intermetallic compound Ni3Al was bonded by us- ing the exothermic synthesis reaction of a mixture of element Ni and Al poweders pre - compacted as the interlayer material.Effects of the key process parameters, such as the heating rate and joining tem- perature as well as the hold time, on the joint formation and microstructural homogeneity were studied. The feasibility of the addition of Al2O3 particles in the joint interlayer for producing intermetallic -ma- trix composite joints are also explored. Results show that the microstructrual homogeneity in the synthe- sized joint interlayer was significantly influenced by the joining process paramenters.The fully synthesized Ni2Al joints exhibited an average tensile strength of 486MPa at R. T. With the addition of Al2O3 ce- ramic particles in the reactants, joints with reighrced Ni3Al - matrix composite interlayer were ob- tained.展开更多
In this paper, the half-strong endomorphisms of the join of split graphs are investigated. We give the conditions under which the half-strong endomorphisms of the join of split graphs form a monoid.
A novel Ag-SiO_(2) braze for Solid Oxide Cells was successfully developed and applied to join Co coated AISI 441 ferritic stainless steel to YSZ-NiO half cells.The braze showed an improved wettability on the coated st...A novel Ag-SiO_(2) braze for Solid Oxide Cells was successfully developed and applied to join Co coated AISI 441 ferritic stainless steel to YSZ-NiO half cells.The braze showed an improved wettability on the coated steel and the YSZ compared to pure Ag.A defect-free steel/YSZ joint was obtained using an Ag-1SiO_(2) braze jointed at 1000℃for 30 min in air.The microstructure of the joints was characterized by scanning electron microscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopy.Furthermore,a Co-Si-O_(2)phase diagram was calculated and used to explain the experimental results and formulate a reaction mechanism.It was found,that during the air brazing process,Co_(3)O_(4)and(Co,Fe)_(3)O_(4)are formed by the oxidation of the prefabricated Co coating.The growth of Cr_(2)O_(3)was effectively impeded by the formed Co-based spinels.In a second step,Co_(2)O_(3)reacts with the SiOpresent in braze.The CoSiOformed by the reaction ensures a firm bonding between the steel and Ag-SiObraze.展开更多
文摘In this investigation, the Gleeble 1500 test simulator was used for carrying out experiments of joining by the pressurized combustion synthesis (PCS). The intermetallic compound Ni3Al was bonded by us- ing the exothermic synthesis reaction of a mixture of element Ni and Al poweders pre - compacted as the interlayer material.Effects of the key process parameters, such as the heating rate and joining tem- perature as well as the hold time, on the joint formation and microstructural homogeneity were studied. The feasibility of the addition of Al2O3 particles in the joint interlayer for producing intermetallic -ma- trix composite joints are also explored. Results show that the microstructrual homogeneity in the synthe- sized joint interlayer was significantly influenced by the joining process paramenters.The fully synthesized Ni2Al joints exhibited an average tensile strength of 486MPa at R. T. With the addition of Al2O3 ce- ramic particles in the reactants, joints with reighrced Ni3Al - matrix composite interlayer were ob- tained.
基金Supported by National Natural Science Foundation of China (Grant Nos. 10571077 and 10971053)
文摘In this paper, the half-strong endomorphisms of the join of split graphs are investigated. We give the conditions under which the half-strong endomorphisms of the join of split graphs form a monoid.
基金the National Natural Science Foundation of China(nos.51805114,52005131,and U1737205)。
文摘A novel Ag-SiO_(2) braze for Solid Oxide Cells was successfully developed and applied to join Co coated AISI 441 ferritic stainless steel to YSZ-NiO half cells.The braze showed an improved wettability on the coated steel and the YSZ compared to pure Ag.A defect-free steel/YSZ joint was obtained using an Ag-1SiO_(2) braze jointed at 1000℃for 30 min in air.The microstructure of the joints was characterized by scanning electron microscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopy.Furthermore,a Co-Si-O_(2)phase diagram was calculated and used to explain the experimental results and formulate a reaction mechanism.It was found,that during the air brazing process,Co_(3)O_(4)and(Co,Fe)_(3)O_(4)are formed by the oxidation of the prefabricated Co coating.The growth of Cr_(2)O_(3)was effectively impeded by the formed Co-based spinels.In a second step,Co_(2)O_(3)reacts with the SiOpresent in braze.The CoSiOformed by the reaction ensures a firm bonding between the steel and Ag-SiObraze.
