Time filter

Source Type

Hu P.,Xi'an University of Architecture and Technology | Wang K.,Xi'an University of Architecture and Technology | Yang F.,Xi'an University of Architecture and Technology | He H.,Xi'an University of Architecture and Technology | And 4 more authors.
Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering | Year: 2014

Based on TZM molybdenum alloy, powder metallurgy methods were using to prepare La-TZM alloy plates with solid-liquid doped rare earth lanthanum and substitution of organic carbon stearic for traditional graphite by mixing, pressing and sintering, hot-rolling, warm-rolling, and cold rolling. La-TZM alloy plates were heated at 300, 450, 600, 800 and 1000℃ in the furnace to calculate the mass loss of the samples. The oxidation behavior was analyzed by the differential thermal analysis. The results show that the tensile strength and elongation of La-TZM plate are 1361.74 MPa and 8.81%, respectively, higher than those of traditional TZM plate. The fiber of La-TZM alloy plate is slim and homogeneous. The second phase of La-TZM alloy plate is smaller and disperses homogeneously. The La-TZM alloy has a more compact structure due to the lanthanum doping. The minute lanthanum oxide particles are pinned at the grain boundaries and refine the grains. Oxide layer generated on the matrix surface can form a compact coating, which effectively blocks the surface from being corroded by oxidation. The oxidation resistance of La-TZM alloys is enhanced, expanding its application range. Copyright © 2014, Northwest Institute for Nonferrous Metal Research. Published by Elsevier BV. All rights reserved


Hu P.,Xi'an University of Architecture and Technology | Wang K.,Xi'an University of Architecture and Technology | Yang F.,Xi'an University of Architecture and Technology | He H.,Xi'an University of Architecture and Technology | And 4 more authors.
Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering | Year: 2014

Using the stearic acid as carbon source to replace graphite, TZM alloy was doped with carbon by a solid-liquid mixing method. The TZM sheet was prepared by hot-rolling, warm-rolling, cold rolling and other techniques. The mechanical properties and metallographic structure of the TZM sheet were analyzed. The results show that the TZM alloy powder is mixed more evenly using stearic acid as carbon source than using graphite as carbon source. The second phase is more and smaller. The second phase particles take a pinning effect on the dislocation, hinder the slip of the grain boundaries, and thus increase the tensile strength of TZM alloy, which is 1168 MPa and improved by 15.3%, and the elongation is 7.66%.


Yang F.,Xi'an University of Architecture and Technology | Wang K.-S.,Xi'an University of Architecture and Technology | Hu P.,Xi'an University of Architecture and Technology | He H.-C.,Xi'an University of Architecture and Technology | And 5 more authors.
Journal of Alloys and Compounds | Year: 2014

Powder metallurgy methods were utilized to prepare lanthanum-doped (La-TZM) and traditional TZM alloy plates. High temperature oxidation experiments along with the differential thermal analysis were employed to study the oxidation behavior of the two kinds of TZM alloys. An extremely volatile oxide layer was generated on the surface of traditional TZM alloy plates when the oxidation started. Molybdenum oxide volatilization exposed the alloy matrix, which was gradually corroded by oxygen, losing its quality with serious surface degradation. The La-TZM alloy has a more compact structure due to the lanthanum doping. The minute lanthanum oxide particles are pinned at the grain boundaries and refine the grains. Oxide layer generated on the matrix surface can form a compact coating, which effectively blocks the surface from being corroded by oxidation. The oxidation resistance of La-TZM alloys has been enhanced, expanding its application range. © 2014 Elsevier B.V. All rights reserved.


Hu P.,China University of Technology | Wang K.-S.,China University of Technology | He H.-C.,China University of Technology | Kang X.-Q.,China University of Technology | And 2 more authors.
Applied Mechanics and Materials | Year: 2013

The conventional TZM alloy plates have limited manufacture and application due to the lacking of enough mechanical property. To resolve this question, La doped TZM alloy plate was made by the powder metallurgy. With solid-solid rare La2O3 doping, sintering, hot rolling, warm rolling and cold rolling, the molybdenum alloy La-TZM plates were got. This kind of TZM alloy has better properties in both strength and elongation. The tensile strength of La-TZM alloy is 1038 MPa, and the elongation is 10.4%. Metallography test and scanning electron microscopy (SEM) are used to examine the microstructure of the La-TZM alloy plate specimen. © (2013) Trans Tech Publications, Switzerland.


Hu P.,Xi'an University of Architecture and Technology | Wang K.,Xi'an University of Architecture and Technology | He H.,Xi'an University of Architecture and Technology | Yang F.,Xi'an University of Architecture and Technology | And 3 more authors.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2013

The TZM alloy plates were prepared by powder metallurgy and rolling method. The microstructure of TZM alloy sintered blank and sheet were observed by metallographic microscope and scanning electron microscope. The results show that sintered blank density is 9.94 g/cm3, the Rockwell hardness is 65 HRC, the microstructure of sintered blank is equiaxed grain, grain uniform distribution, the average grain size is 10 μm and has clear outline of the grain boundary. The density of TZM alloy sheet is 10 g/cm3 after rolling, the tensile strength is 914 MPa and the elongation is 4.6%. Analysis and comparison of the microstructure for the annealed sample under 1000, 1100, 1200, 1300, 1400, 1500 and 1600°C show that the TZM alloy sheet is in the recovery stage at 1000°C, 1100°C, and in start recrystallization state at 1200°C, and fully recrystallized at 1600°C.


Hu P.,Xi'an University of Architecture and Technology | Wang K.,Xi'an University of Architecture and Technology | Wang H.,Xian Electrical Furnace Institute Co. | He H.,Xi'an University of Architecture and Technology | And 3 more authors.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2013

Nanocrystalline Mn-Zn ferrite powder was prepared by nitrate-citrate auto-combustion synthetic method and subsequently annealed at different temperatures in muffle furnace without protective atmosphere. The effects of heat treatment temperature on crystalline phase formation, microstructure and magnetic properties of the Mn-Zn ferrite were investigated by FTIR, TG-DTA, XRD, SEM and VSM. The results show that when annealed above 550°C in air, the ferrite decomposes to Fe2O3 and Mn2O3, and has poor magnetic properties, when annealed above 1100°C, Fe2O3 and Mn2O3 are dissolved, and the sample annealed at 1200°C is composed of pure ferrite phase with good crystallinity and uniform grain and has larger saturation magnetization (Ms=48.15 emu·g-1) compared with that of the auto-combusted ferrite powder.


Hu P.,Xi'an University of Architecture and Technology | Yang F.,Xi'an University of Architecture and Technology | Wang K.-S.,Xi'an University of Architecture and Technology | Yu Z.-T.,Xi'an University of Architecture and Technology | And 6 more authors.
International Journal of Refractory Metals and Hard Materials | Year: 2015

Abstract Powder metallurgy methods were utilized to prepare lanthanum-doped titanium-zirconium-molybdenum (La-TZM) and traditional TZM alloy plates. Tensile and Charpy impact tests were employed to study the room temperature and cryogenic mechanical properties of the two kinds of TZM alloys. For the same process conditions, the lanthanum doping has significantly improved the tensile strength and elongation, which increased by 28.2% and 32.8%, respectively. For these process conditions, the La-TZM has higher density and smaller evenly distributed secondary phases. Compared with TZM, the secondary phase in La-TZM is finer, and hinders the spreading of cracks. This is why the La-TZM alloy plates have higher strength and elongation. By doping lanthanum, the ductile-to-brittle transition temperature of the TZM alloy decreased from - 80 °C to - 120°C. The secondary phase La particles refine the grain and hinder fracture expansion across the grains during the impact fracture of the La-TZM alloy. TZM alloy improved room temperature and cryogenic mechanical properties significantly expand its application range. © 2015 Elsevier Ltd.


Hu P.,Xi'an University of Architecture and Technology | Wang K.,Xi'an University of Architecture and Technology | Kang X.,Xi'an University of Architecture and Technology | He H.,Xi'an University of Architecture and Technology | And 3 more authors.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2013

The La-TZM alloy plates were prepared by powder metallurgy, and the effect of rolling ways on mechanical properties of plates was studied. The results show that the plates made by cross rolling method can obtain more uniform deformation, less anisotropy, and the mechanical properties of the longitudinal and lateral directions are about equal. Under different temperatures annealing state, the room temperature tensile strength and yield strength of the cross rolling plate are higher than that of the one-way rolling plate, but the elongation is improved greatly. The recrystallization temperature of the cross rolling plate is lower than that of the one-way rolling plate.

Loading XiAn Electrical Furnace Institute Co. collaborators
Loading XiAn Electrical Furnace Institute Co. collaborators