The Experts below are selected from a list of 6636 Experts worldwide ranked by ideXlab platform
Wang Zi-dong - One of the best experts on this subject based on the ideXlab platform.
-
Research on Continuous Unidirectional Solidification Equipment under Conditions of Vacuum Melting and Argon Shield
Research Studies on Foundry Equipment, 2004Co-Authors: Wang Zi-dongAbstract:Continuous unidirectional solidification equipment under conditions of Vacuum Melting and argon shield is designed and made on the basis of original traditional continuous unidirectional solidification equipment and Vacuum system.This paper will discuss especially on the structure and working principle of continuous unidirectional solidification equipment under conditions of Vacuum Melting and argon shield.This equipment is a new one in the field of continuous casting.
-
Vacuum Melting and Argon Protecting Continuous Unidirectional Solidification Technology
Journal of University of Science and Technology Beijing, 2004Co-Authors: Wang Zi-dongAbstract:The Vacuum Melting and argon protecting continuous unidirectional solidification technology was introduced, which combines Vacuum inductive Melting with continuous unidirectional solidification. Integrating Melting, purification and solidification, the system has convenient control, strong ability to mix and oxidize and higher efficiency, and can produce pure and high-class materials with unidirectional microstructure. A Cu bar of 8 m in length with columned crystals, was made with self-made equipment based on the technology and its microstructure and properties were analyzed.
Shu-chao Guo - One of the best experts on this subject based on the ideXlab platform.
-
microstructure and thermoelectric properties of bi 0 5 na 0 02 sb 1 48 x in x te 3 alloys fabricated by Vacuum Melting and hot pressing
Rare Metals, 2015Co-Authors: Xingkai Duan, Wang-nian Zhang, Yuezhen Jiang, Shu-chao GuoAbstract:The Bi0.5Na0.02Sb1.48−x In x Te3 alloys (x = 0.02–0.20) were synthesized by Vacuum Melting and hot pressing methods at 753 K, 60 MPa for 30 min. Effects of Na and In dual partial substitutions for Sb on the thermoelectric properties were investigated from 300 to 500 K. Substituting Sb with Na and In can enhance the Seebeck coefficient effectively near room temperature. The electrical resistivity of the Na and In dual-doping samples is higher within the whole test temperature range. The Bi0.5Na0.02Sb1.48−x In x Te3 samples (x = 0.02, 0.06) play a great role in optimizing the thermal conductivity. As for the Bi0.5 Na0.02Sb1.46In0.02Te3 alloy, the minimum value of thermal conductivity reaches 0.53 W·m−1·K−1 at 320 K. The thermoelectric performance of the Na and In dual-doped samples is greatly improved, and a figure of merit ZT of 1.26 is achieved at 300 K for the Bi0.5Na0.02Sb1.42In0.06Te3, representing 26 % enhancement with respect to ZT = 1.0 of the undoped sample.
-
Microstructure and thermoelectric properties of Bi 0.5 Na 0.02 Sb 1.48−x In x Te 3 alloys fabricated by Vacuum Melting and hot pressing
Rare Metals, 2013Co-Authors: Xingkai Duan, Wang-nian Zhang, Yuezhen Jiang, Shu-chao GuoAbstract:The Bi0.5Na0.02Sb1.48−x In x Te3 alloys (x = 0.02–0.20) were synthesized by Vacuum Melting and hot pressing methods at 753 K, 60 MPa for 30 min. Effects of Na and In dual partial substitutions for Sb on the thermoelectric properties were investigated from 300 to 500 K. Substituting Sb with Na and In can enhance the Seebeck coefficient effectively near room temperature. The electrical resistivity of the Na and In dual-doping samples is higher within the whole test temperature range. The Bi0.5Na0.02Sb1.48−x In x Te3 samples (x = 0.02, 0.06) play a great role in optimizing the thermal conductivity. As for the Bi0.5 Na0.02Sb1.46In0.02Te3 alloy, the minimum value of thermal conductivity reaches 0.53 W·m−1·K−1 at 320 K. The thermoelectric performance of the Na and In dual-doped samples is greatly improved, and a figure of merit ZT of 1.26 is achieved at 300 K for the Bi0.5Na0.02Sb1.42In0.06Te3, representing 26 % enhancement with respect to ZT = 1.0 of the undoped sample.
Seiichi Takaki - One of the best experts on this subject based on the ideXlab platform.
-
Ultra-purification of iron by ultra-high Vacuum Melting
Vacuum, 1999Co-Authors: Kenji Abiko, Seiichi TakakiAbstract:The properties of iron and steel have been improved by the development of the processes of refining, the alloying of useful elements and the control of microstructure. For the refining process of iron and steel making, the harmful impurities are removed by the transportation into slag. However, there is a technological limit to making ultra-high purity iron and steel by slag reaction. Consequently, ultra-purification technology is demanded for remarkable development of iron and steel. In the present investigation, a new induction Melting furnace containing a copper-cold-crucible has been designed and constructed using ultra-high Vacuum technology for purification of iron. The main chamber can be evacuated to 6.7 × 10-8Pa as the base pressure. The furnace can melt iron of 10 kg, at most, within 300 s. By Melting under atmosphere of 7.5 × 10-6Pa, the total amount of carbon, nitrogen, oxygen, sulfur and hydrogen in iron of 10 kg is able to be reduced to less than 10 mass ppm. Especially, the Melting process in the atmosphere of ultra-high Vacuum is effective for the reduction of oxygen in iron. It is concluded that ultra-high Vacuum Melting technology is quite useful for ultra-purification of iron, especially the reduction of gaseous impurities.
Lin Chen - One of the best experts on this subject based on the ideXlab platform.
-
Study on fatigue of Vacuum Melting Co base alloy - WC hardening coating
Ordnance Material Science and Engineering, 2005Co-Authors: Lin ChenAbstract:Hardness of substrate was increased with normalizing. The hardness distribution and microstructure of coatings were researched. By means of bend - rotation fatigue tests, fatigue strength of coating and uncoating specimens are compared after the normalizing. The results show that, the hardness of substrate was increased; the hardness and microstructure of coating was hardly changed. In the same lifetime, fatigue strength of coating specimens increased about 60 - 80 MPa.
-
Wear Resistance of Vacuum Melting Co Base Alloy-WC Composite Coating
Materials for Mechanical Engineering, 2003Co-Authors: Lin ChenAbstract:Using fusing sintering method, alloy coatings were covered on the surface of carbon steel. A series of Co base alloyWC coatings have been obtained on the surface of 45 steel with Vacuum Melting method. The microhardness charactersitic of several coatings with different WC contents were observed. Their wear resistance was studied. The relation between microhardness and wear resistance was analyzed. Also chemical composition of WC hard phase was measured with EDS and combination of WC and Co base alloy was anayzed. On the basis of test results, in less 60% content, the more WC, the higher microhardness and wear resistance. The application of composite coatings is suggested.
Jin Haixia - One of the best experts on this subject based on the ideXlab platform.
-
Synthesis of Sb_2Se_3 Thermoelectric Material by Vacuum Melting and Its Microstructure
Hot Working Technology, 2012Co-Authors: Jin HaixiaAbstract:Sb2Se3 powders were fabricated by the methods of sealing high pure Sb and Se in a Vacuum quartz tube and smelt at 800 ℃ for 12h.Sb2Se3 bulk materials were prepared by hot-press sintering at 470 ℃ under 60MPa for 0.5 h in Vacuum.Phase structure and microscopic topography of the samples were characterized by XRD and SEM.The results show that the diffraction peaks of the powders alloyed in Vacuum and the bulk materials by hot-press sintering mainly correspond to the standard Sb2Se3 reference code(01-072-1184).The bulk samples of Sb2Se3 have a plenty of sheet layer structures on the cross section parallel to the hot-press direction,and a few coarse sheet layers.Sheet layer structures about 1 μm in thickness have preferential growth along a certain direction.On the cross section perpendicular to the hot-press direction,the microstructures are mainly sheet layers with a few nearly spherical structure.However,sheet layer structures are short and thin with a few coarseness,and have heterogeneous structures.the atomic percentage of the elements Sb and Se in the bulk materials by hot-press sintering are 40.68% and 59.32%,respectively, approaching 2 ∶ 3.
-
Microstructure of Sb_2Se_3 Thermoelectric Material Prepared by Vacuum Melting and Hot-pressing
Hot Working Technology, 2012Co-Authors: Jin HaixiaAbstract:High pure Sb and Se sealed in a Vacuum quartz tube were smelted at 800℃ for 8 h.Sb2Se3 powders were fabricated by grinding the ingot.Sb2Se3 bulk materials were prepared by hot-press sintering at 470 ℃ under 60 MPa for 0.5 h in Vacuum.The phase structure and microscopic topography of the samples were characterized by XRD and SEM.The results show that the diffraction peaks of powders alloyed and bulk materials by hot-press sintering mainly corresponding to the standard Sb2Se3 reference code(01-072-1184).The bulk samples of Sb2Se3 by hot-press sintering have a plenty of sheet layer structures on the cross section perpendicularing and paralleling the hot-press direction.Preferentially,the oriented sheet layer structures were obtained on the cross section paralleling to the hot-press direction.However,the sheet layer structures on the cross section perpendicularing to the hot-press direction distributes more homogeneously and has fully crystallization than that on the cross section paralleling to the hot-press direction.The atomic percentage of element Sb and Se is 40.68% and 59.32% respectively,approaching to 2 ∶ 3.
