Al-doped ZnO （AZO） target was prepared by hot pressing using ZnO and Al2O3 powder in mass ratio of 98：2.The effects of hot pressing conditions including temperature,pressure and preserving time on relative density ...Al-doped ZnO （AZO） target was prepared by hot pressing using ZnO and Al2O3 powder in mass ratio of 98：2.The effects of hot pressing conditions including temperature,pressure and preserving time on relative density were investigated.Pore evolution and phase structure change during densification process were studied.The results show that AZO target with super high relative density of 99% was prepared by two-stage hot pressing method under pressure of 35MPa,temperature of 1 050℃ and 1 150℃ with preserving time of 1 h,respectively.At temperature around 1 050℃,the number of isolated pore wasminimum.At temperature lower than 900℃,there existed Al2O3 phase.At temperature higher than 1 000℃,ZnAl2O4 phase was generated and its content was increased with temperature increasing.Hot pressing method had the advantage over pressureless sintering that the content of ZnAl2O4 was lower and sintering temperature could be also lower.With increasing the hot pressing temperature and preserving time,the electric resistivity of AZO target decreased greatly.A low resistivity of 3 10-3 cm was achieved under the temperature of 1 100℃,pressure of 35MPa and preserving time of 10 h.展开更多
Studies of pressure-volume curves have shown that the filter pressing behaviours depend on pH values of the alumina dispersion. Densimetry and porosimetry of the filter cakes have revealed that higher density, smalle...Studies of pressure-volume curves have shown that the filter pressing behaviours depend on pH values of the alumina dispersion. Densimetry and porosimetry of the filter cakes have revealed that higher density, smaller mode pore size and lower specific volume of total pores can be achieved by controlling electrostabilization. (Author abstract) 9 Refs.展开更多
In this paper, a new of oxygen fugaeity controltechnique that can be widely applied to in-situ measurement of the grain interior electrical conductivities of minerals and rocks is presented for high temperature and hi...In this paper, a new of oxygen fugaeity controltechnique that can be widely applied to in-situ measurement of the grain interior electrical conductivities of minerals and rocks is presented for high temperature and high pressure. Inside the sample assembly, a metal and corresponding metal oxide form a solid oxygen buffer. The principle of this technique is to randomly monitor and adjust oxygen fugacity in the large-volume multi-anvil press by changing the types of solid oxygen buffer, metal shielding case and electrodes. At a pressure of up to 5.0 GPa and a temperature of up to 1423 K, the electrical conductivities of the dry peridotite are tested under the conditions of different oxygen fugacities. By virtue of this new technique, more and more reasonable and accurate laboratory electrical property data will be successfully obtained under controlled thermodynamic conditions.展开更多
粉末近净成形(Powder metallurgy near net shaping,PM-NNS)技术能够制备出具有优异综合力学性能的粉末合金复杂部件。介绍了粉末热等静压(Hot isostatic pressing,HIP)近净成形技术原理及优势,综述了近年来国内外粉末近净成形在航天发...粉末近净成形(Powder metallurgy near net shaping,PM-NNS)技术能够制备出具有优异综合力学性能的粉末合金复杂部件。介绍了粉末热等静压(Hot isostatic pressing,HIP)近净成形技术原理及优势,综述了近年来国内外粉末近净成形在航天发动机领域的研究现状,从工艺路线和构件研制两方面展开,简述了构件制备过程的影响因素及缺陷控制,结合中国科学院金属研究所粉末近净成形技术在航天发动机领域的研究及应用情况,总结了粉末近净成形技术当前存在的主要问题及发展方向,以期进一步拓宽该技术的应用范围。展开更多
基金Project(31001) supported by the Technology Development Foundation of Ministry of Science and Technology,China
文摘Al-doped ZnO （AZO） target was prepared by hot pressing using ZnO and Al2O3 powder in mass ratio of 98：2.The effects of hot pressing conditions including temperature,pressure and preserving time on relative density were investigated.Pore evolution and phase structure change during densification process were studied.The results show that AZO target with super high relative density of 99% was prepared by two-stage hot pressing method under pressure of 35MPa,temperature of 1 050℃ and 1 150℃ with preserving time of 1 h,respectively.At temperature around 1 050℃,the number of isolated pore wasminimum.At temperature lower than 900℃,there existed Al2O3 phase.At temperature higher than 1 000℃,ZnAl2O4 phase was generated and its content was increased with temperature increasing.Hot pressing method had the advantage over pressureless sintering that the content of ZnAl2O4 was lower and sintering temperature could be also lower.With increasing the hot pressing temperature and preserving time,the electric resistivity of AZO target decreased greatly.A low resistivity of 3 10-3 cm was achieved under the temperature of 1 100℃,pressure of 35MPa and preserving time of 10 h.
文摘Studies of pressure-volume curves have shown that the filter pressing behaviours depend on pH values of the alumina dispersion. Densimetry and porosimetry of the filter cakes have revealed that higher density, smaller mode pore size and lower specific volume of total pores can be achieved by controlling electrostabilization. (Author abstract) 9 Refs.
基金supported by the Knowledge Innovation Key Orientation Project of the Chinese Academy of Sciences (CAS) (Grant Nos. KZCX2-YW-Q08-3-4,KZCX2-YW-QN110,and KZCX3-SW-124)Large-scale Scientific Apparatus Development Program of CAS (Grant No. YZ200720)+1 种基金the National High Technology Research and Development Program of China (Grant No. 2006AA09Z205)the National Natural Science Foundation of China (Grant Nos. 40974051,40704010 and 40573046)
文摘In this paper, a new of oxygen fugaeity controltechnique that can be widely applied to in-situ measurement of the grain interior electrical conductivities of minerals and rocks is presented for high temperature and high pressure. Inside the sample assembly, a metal and corresponding metal oxide form a solid oxygen buffer. The principle of this technique is to randomly monitor and adjust oxygen fugacity in the large-volume multi-anvil press by changing the types of solid oxygen buffer, metal shielding case and electrodes. At a pressure of up to 5.0 GPa and a temperature of up to 1423 K, the electrical conductivities of the dry peridotite are tested under the conditions of different oxygen fugacities. By virtue of this new technique, more and more reasonable and accurate laboratory electrical property data will be successfully obtained under controlled thermodynamic conditions.
文摘粉末近净成形(Powder metallurgy near net shaping,PM-NNS)技术能够制备出具有优异综合力学性能的粉末合金复杂部件。介绍了粉末热等静压(Hot isostatic pressing,HIP)近净成形技术原理及优势,综述了近年来国内外粉末近净成形在航天发动机领域的研究现状,从工艺路线和构件研制两方面展开,简述了构件制备过程的影响因素及缺陷控制,结合中国科学院金属研究所粉末近净成形技术在航天发动机领域的研究及应用情况,总结了粉末近净成形技术当前存在的主要问题及发展方向,以期进一步拓宽该技术的应用范围。
