Two types of alumina dispersion-strengthened copper（ADSC） alloys were fabricated by a novel in-situ reactive synthesis（IRS） and a traditional internal oxidation（IO） process. The features of alumina dispersoids i...Two types of alumina dispersion-strengthened copper（ADSC） alloys were fabricated by a novel in-situ reactive synthesis（IRS） and a traditional internal oxidation（IO） process. The features of alumina dispersoids in these ADSC alloys were investigated by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. It is found that nano-sized γ-Al2O3 particles of approximately 10 nm in diameter are homogeneously distributed in the IRS-ADSC composites. Meanwhile, larger-sized, mixed crystal structure alumina with rod-shaped morphology is embedded in the IO-ADSC alloy. The IRS-ADSC composites can obtain better mechanical and physical properties than the IO-ADSC composites; the tensile strength of the IRS-ADSC alloy can reach 570 MPa at room temperature, its electrical conductivity is 85% IACS, and the Rockwell hardness can reach 86 HRB.展开更多
Three different castables based on the Al_2O_3–MgO –CaO system were prepared as steel-ladle purging plug refractories： corundum-based low-cement castable（C-LCC）, corundum-spinel-based low-cement castable（C-S-LCC...Three different castables based on the Al_2O_3–MgO –CaO system were prepared as steel-ladle purging plug refractories： corundum-based low-cement castable（C-LCC）, corundum-spinel-based low-cement castable（C-S-LCC）, and corundum-spinel no-cement castable（C-S-NCC）（hydratable alumina（ρ-Al_2O_3） bonded）. The fracture behavior at room temperature was tested by the method of ＂wedge-splitting＂ on samples pre-fired at different temperatures; the specific fracture energy G′f and notched tensile strength σNT were obtained from these tests. In addition, the Young＇s modulus E was measured by the method of resonance frequency of damping analysis（RFDA）. The thermal stress resistance parameter R′′′′ calculated using the values of G′f, σNT, and E was used to evaluate the thermal shock resistance of the materials. According to the microstructure analysis results, the sintering effect and the bonding type of the matrix material were different among these three castables, which explains their different fracture behaviors.展开更多
基金financially supported by the National Natural Science Foundation of China(NO.51464013)the Dr.Initialization Fund of Jiangxi University of Science and Technology(No.jxxjbs14013)
文摘Two types of alumina dispersion-strengthened copper（ADSC） alloys were fabricated by a novel in-situ reactive synthesis（IRS） and a traditional internal oxidation（IO） process. The features of alumina dispersoids in these ADSC alloys were investigated by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. It is found that nano-sized γ-Al2O3 particles of approximately 10 nm in diameter are homogeneously distributed in the IRS-ADSC composites. Meanwhile, larger-sized, mixed crystal structure alumina with rod-shaped morphology is embedded in the IO-ADSC alloy. The IRS-ADSC composites can obtain better mechanical and physical properties than the IO-ADSC composites; the tensile strength of the IRS-ADSC alloy can reach 570 MPa at room temperature, its electrical conductivity is 85% IACS, and the Rockwell hardness can reach 86 HRB.
文摘Three different castables based on the Al_2O_3–MgO –CaO system were prepared as steel-ladle purging plug refractories： corundum-based low-cement castable（C-LCC）, corundum-spinel-based low-cement castable（C-S-LCC）, and corundum-spinel no-cement castable（C-S-NCC）（hydratable alumina（ρ-Al_2O_3） bonded）. The fracture behavior at room temperature was tested by the method of ＂wedge-splitting＂ on samples pre-fired at different temperatures; the specific fracture energy G′f and notched tensile strength σNT were obtained from these tests. In addition, the Young＇s modulus E was measured by the method of resonance frequency of damping analysis（RFDA）. The thermal stress resistance parameter R′′′′ calculated using the values of G′f, σNT, and E was used to evaluate the thermal shock resistance of the materials. According to the microstructure analysis results, the sintering effect and the bonding type of the matrix material were different among these three castables, which explains their different fracture behaviors.
