The ultrafine crystalline CuCr50（Cr 50 wt%） alloys were fabricated by a combination of mechanical alloying and spark plasma sintering process. The effects of milling time on crystallite size and solid solubility of ...The ultrafine crystalline CuCr50（Cr 50 wt%） alloys were fabricated by a combination of mechanical alloying and spark plasma sintering process. The effects of milling time on crystallite size and solid solubility of the CuCr50 composite powders were investigated. The results showed that crystallite size of powders decreases gradually and solid solubility of Cr in Cu was extended with increasing milling time. The minimal crystallite size about 10 nm and the maximum solid solubility about 8.4 at%（i e, 7 wt%） were obtained at 60 h. The microstructure of ultrafine crystalline CuCr50 alloy was analyzed by SEM and TEM, which contains two kinds of size scale Cr particles of 2 μm and 50-150 nm, distributing homogeneously in matrix, respectively. The arc erosion characteristics of ultrafine crystalline CuCr50 alloy were investigated by the vacuum contact simulation test device in low D.C. voltage and low current（24 V/10 A）. A commercial microcrystalline CuCr50 alloy was also investigated for comparison. Experiments indicate that the cathode mass loss of ultrafine crystalline CuCr50 contact material is higher than that of microcrystalline CuCr50 material, but its eroded surface morphology by the arc is uniform without obvious erosion pits. While the surface of microcrystalline CuCr50 contact is seriously eroded in local area by the arc, an obvious erosion pit occurred in the core part. Therefore, the ability of arc erosion resistance of ultrafine crystalline CuCr50 alloy is improved compared to that of microcrystalline CuCr50 material.展开更多
This article is presenting history of stone casting and analysis of basalt raw materials assessment from other countries for stone casting technology and various basalts compositions were considered. Analytical method...This article is presenting history of stone casting and analysis of basalt raw materials assessment from other countries for stone casting technology and various basalts compositions were considered. Analytical methods for calculating composition of charge require a long calculation time and plotting diagrams, each method has its own advantages and disadvantages. As a research significance, we have proposed an experimental calculation method for calculating raw materials after charging. Analysis of the composition, structure of basalts and charging materials were used in the stone casting technology. According to the comparison method, the required amount of charging materials was calculated for the Suluu-Terek 1, Suluu-Terek 2 and Berestovetsk deposits. The calculated data was confirmed by experimental melts in the process of stone casting.展开更多
基金Funded by the National Natural Science Foundation of China(No.51575406)the Science Research Foundation for Wuhan Institute of Technology(No.K201519)
文摘The ultrafine crystalline CuCr50（Cr 50 wt%） alloys were fabricated by a combination of mechanical alloying and spark plasma sintering process. The effects of milling time on crystallite size and solid solubility of the CuCr50 composite powders were investigated. The results showed that crystallite size of powders decreases gradually and solid solubility of Cr in Cu was extended with increasing milling time. The minimal crystallite size about 10 nm and the maximum solid solubility about 8.4 at%（i e, 7 wt%） were obtained at 60 h. The microstructure of ultrafine crystalline CuCr50 alloy was analyzed by SEM and TEM, which contains two kinds of size scale Cr particles of 2 μm and 50-150 nm, distributing homogeneously in matrix, respectively. The arc erosion characteristics of ultrafine crystalline CuCr50 alloy were investigated by the vacuum contact simulation test device in low D.C. voltage and low current（24 V/10 A）. A commercial microcrystalline CuCr50 alloy was also investigated for comparison. Experiments indicate that the cathode mass loss of ultrafine crystalline CuCr50 contact material is higher than that of microcrystalline CuCr50 material, but its eroded surface morphology by the arc is uniform without obvious erosion pits. While the surface of microcrystalline CuCr50 contact is seriously eroded in local area by the arc, an obvious erosion pit occurred in the core part. Therefore, the ability of arc erosion resistance of ultrafine crystalline CuCr50 alloy is improved compared to that of microcrystalline CuCr50 material.
文摘This article is presenting history of stone casting and analysis of basalt raw materials assessment from other countries for stone casting technology and various basalts compositions were considered. Analytical methods for calculating composition of charge require a long calculation time and plotting diagrams, each method has its own advantages and disadvantages. As a research significance, we have proposed an experimental calculation method for calculating raw materials after charging. Analysis of the composition, structure of basalts and charging materials were used in the stone casting technology. According to the comparison method, the required amount of charging materials was calculated for the Suluu-Terek 1, Suluu-Terek 2 and Berestovetsk deposits. The calculated data was confirmed by experimental melts in the process of stone casting.
