A novel in situ reaction system Al Zr O was developed. In situ Al 3Zr and Al 2O 3 particulate reinforced A356 alloy matrix composites have been fabricated by direct melt reaction method. The results show that the maxi...A novel in situ reaction system Al Zr O was developed. In situ Al 3Zr and Al 2O 3 particulate reinforced A356 alloy matrix composites have been fabricated by direct melt reaction method. The results show that the maximum sizes of Al 3Zr and Al 2O 3 particulates synthesized in the system ZrOCl 2 A356 are 1 μm and 3 μm respectively, and they are well distributed in the matrix. The investigation shows that the Al 3Zr crystal is in the shape of polyhedron and rectangle. There is a faceted growth phenomenon on Al 3Zr crystal surface. It is firstly found that the Al 3Zr crystal grows in the mechanism of twinning. The twinning plane is (1 1 4), and the twinning direction is [2 2 1] . The crystal morphology of in situ α Al 2O 3 particulate is rectangle or sphere. Furthermore, (Al 3Zr+Al 2O 3) p/A356 composites have not only higher tensile strength at room temperature (376.2 MPa) but also higher yield strength (319.4 MPa) and higher tensile strength at elevated temperature (200 ℃) than those of the A356 alloy. The dry sliding wear test shows that the wear resistance of the (Al 3Zr+Al 2O 3) p/A356 composites is greatly enhanced with increasing particulate volume fraction.展开更多
The influence of rare earth Y on the microstructure and mechanical properties of Al-Zr alloy produced by dynamic ECAE was studied by OLYMPUS-BX51M optical microscope(OM),S4800 energy disperse spectroscopy(EDS)and SANS...The influence of rare earth Y on the microstructure and mechanical properties of Al-Zr alloy produced by dynamic ECAE was studied by OLYMPUS-BX51M optical microscope(OM),S4800 energy disperse spectroscopy(EDS)and SANS CMT5105 electronic universal material testing machine,and the corresponding equivalent conductivity was also investigated by using QJ48 DC electric bridge.The results show that the tensile strength of Al-Zr conductor first increases and then decreases with the increase of the aging time and temperature,and the highest tensile value can be obtained under the aging temperature of 160°C for 4 h.The ductility and the resistivity of the Al-Zr alloy have inverse proportion to the aging time.The rare earth Y has significantly improved the electrical and mechanical properties of Al-0.3%Zr heat-resistant alloy.In this study,the tensile strength and the elongation of the Al-0.3%Zr-0.2%Y alloy,after aging treatment at 220°C for 14 h,are about 278.49 MPa and 6.7%,respectively,and the equivalent conductivity is about 59.6 IACS.Hence the synthetical properties of the Y-containing alloy are significantly improved compared with traditional Al-0.3%Zr alloy.展开更多
文摘A novel in situ reaction system Al Zr O was developed. In situ Al 3Zr and Al 2O 3 particulate reinforced A356 alloy matrix composites have been fabricated by direct melt reaction method. The results show that the maximum sizes of Al 3Zr and Al 2O 3 particulates synthesized in the system ZrOCl 2 A356 are 1 μm and 3 μm respectively, and they are well distributed in the matrix. The investigation shows that the Al 3Zr crystal is in the shape of polyhedron and rectangle. There is a faceted growth phenomenon on Al 3Zr crystal surface. It is firstly found that the Al 3Zr crystal grows in the mechanism of twinning. The twinning plane is (1 1 4), and the twinning direction is [2 2 1] . The crystal morphology of in situ α Al 2O 3 particulate is rectangle or sphere. Furthermore, (Al 3Zr+Al 2O 3) p/A356 composites have not only higher tensile strength at room temperature (376.2 MPa) but also higher yield strength (319.4 MPa) and higher tensile strength at elevated temperature (200 ℃) than those of the A356 alloy. The dry sliding wear test shows that the wear resistance of the (Al 3Zr+Al 2O 3) p/A356 composites is greatly enhanced with increasing particulate volume fraction.
基金Funded by the Science and Research Program of Chongqing Municipal Education Commission(No.KJZD-M201801401)Talent Start Fund of Yangtze Normal University(No.2018KYQD006)
文摘The influence of rare earth Y on the microstructure and mechanical properties of Al-Zr alloy produced by dynamic ECAE was studied by OLYMPUS-BX51M optical microscope(OM),S4800 energy disperse spectroscopy(EDS)and SANS CMT5105 electronic universal material testing machine,and the corresponding equivalent conductivity was also investigated by using QJ48 DC electric bridge.The results show that the tensile strength of Al-Zr conductor first increases and then decreases with the increase of the aging time and temperature,and the highest tensile value can be obtained under the aging temperature of 160°C for 4 h.The ductility and the resistivity of the Al-Zr alloy have inverse proportion to the aging time.The rare earth Y has significantly improved the electrical and mechanical properties of Al-0.3%Zr heat-resistant alloy.In this study,the tensile strength and the elongation of the Al-0.3%Zr-0.2%Y alloy,after aging treatment at 220°C for 14 h,are about 278.49 MPa and 6.7%,respectively,and the equivalent conductivity is about 59.6 IACS.Hence the synthetical properties of the Y-containing alloy are significantly improved compared with traditional Al-0.3%Zr alloy.
