A heat resistant gradient composite was synthesized in situ on steel with the self-propagating high temperature synthesis （SHS） reaction of 3Ni-Al-Ti-C system during casting. The phases, microstructure, and composit...A heat resistant gradient composite was synthesized in situ on steel with the self-propagating high temperature synthesis （SHS） reaction of 3Ni-Al-Ti-C system during casting. The phases, microstructure, and composition of the composite were analyzed by using an X-ray diffractometer （XRD）, and a scanning electron microscope （SEM） coupled with an energy-dispersive X-ray spectroscope （EDS）. The formation mechanism of the composite is also discussed. TiC/Ni3 Al/steel gradient composite is achieved by forming the gradient distributions of Fe, Ni, and Al, accompanied with the gradient variation of the microstructure from TiC/Nia A1, to TiC/Ni3 Al/steel, and to steel. The composite is in situ synthesized through whole reaction of 3Ni-Al-Ti-C system in liquid steel and densification procedure, and the liquid steel infiltrates into pores in the SHS product and forces liquid Ni3Al to form self-compaction further.展开更多
The characteristics of microstructures and mechanical properties of the multi-layer spray deposited SiCP/Al-6.5Fe-0.6V-1.3Si,SiCP/Al-8.5Fe-1.3V-1.7Si and SiCP/Al-10Fe-1.3V-2Si composite sheets obtained by rolling afte...The characteristics of microstructures and mechanical properties of the multi-layer spray deposited SiCP/Al-6.5Fe-0.6V-1.3Si,SiCP/Al-8.5Fe-1.3V-1.7Si and SiCP/Al-10Fe-1.3V-2Si composite sheets obtained by rolling after extruding were investigated. The evolution of the grain and phases of these composites during processing were examined,and the influence of the microstructures on the mechanical properties was analyzed. The experimental results show that the ultimate tensile strengths σb of the three kinds of composite sheets are 420,535,470 MPa respectively at room temperature,and 232,285,300 MPa at 315 ℃ and 148,180,200 MPa at 400 ℃. The excellent mechanical properties can be attributed to the high solid solubility,fine grain size,Al12(Fe,V)3Si precipitation particles and the SiC particles. And the composition of the matrix alloy has an obvious effect on the mechanical properties of the as-rolled sheets.展开更多
基金Item Sponsored by National High-Tech Research and Development Programof China (2002AA331180)High Education Council of Jiangsu Province for Key-Lab Project (Kjsmcx 04004)
文摘A heat resistant gradient composite was synthesized in situ on steel with the self-propagating high temperature synthesis （SHS） reaction of 3Ni-Al-Ti-C system during casting. The phases, microstructure, and composition of the composite were analyzed by using an X-ray diffractometer （XRD）, and a scanning electron microscope （SEM） coupled with an energy-dispersive X-ray spectroscope （EDS）. The formation mechanism of the composite is also discussed. TiC/Ni3 Al/steel gradient composite is achieved by forming the gradient distributions of Fe, Ni, and Al, accompanied with the gradient variation of the microstructure from TiC/Nia A1, to TiC/Ni3 Al/steel, and to steel. The composite is in situ synthesized through whole reaction of 3Ni-Al-Ti-C system in liquid steel and densification procedure, and the liquid steel infiltrates into pores in the SHS product and forces liquid Ni3Al to form self-compaction further.
基金Projects(50304008) supported by the National Natural Science Foundation of China
文摘The characteristics of microstructures and mechanical properties of the multi-layer spray deposited SiCP/Al-6.5Fe-0.6V-1.3Si,SiCP/Al-8.5Fe-1.3V-1.7Si and SiCP/Al-10Fe-1.3V-2Si composite sheets obtained by rolling after extruding were investigated. The evolution of the grain and phases of these composites during processing were examined,and the influence of the microstructures on the mechanical properties was analyzed. The experimental results show that the ultimate tensile strengths σb of the three kinds of composite sheets are 420,535,470 MPa respectively at room temperature,and 232,285,300 MPa at 315 ℃ and 148,180,200 MPa at 400 ℃. The excellent mechanical properties can be attributed to the high solid solubility,fine grain size,Al12(Fe,V)3Si precipitation particles and the SiC particles. And the composition of the matrix alloy has an obvious effect on the mechanical properties of the as-rolled sheets.
