Xian Super Crystal Science and Technology Development Co.

Fengcheng, China

Xian Super Crystal Science and Technology Development Co.

Fengcheng, China
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Cao F.,Northeastern University China | Xue G.,Northeastern University China | Xue G.,Xian Supercrystal Science and Technology Development Co. | Xu G.,Northeastern University China
Materials Science and Engineering A | Year: 2017

The microstructures, mechanical properties, deformation mechanism and cavitation growth of Mg-10.2Li-2.1Al-2.23Zn-0.2Sr alloy subjected to multidirectional forging and rolling (MDFR) were studied to examine the deformability of the Mg-Li alloy. X-ray diffraction (XRD) results confirm the existence of α (Mg) and β (Li) phases and Mg17Al12, Al4Sr and LiMgAl2 intermetallic compounds. Studies of the microstructures reveal that a thin banded-grained microstructure with a grain size less than 3.75 µm is obtained via MDFR and annealing at 523 K for 1 h. There were significant grain refinements. The maximum elongation to failure was 712.1%, and this was obtained in the current alloy at 623 K with a strain rate of 1.67 × 10−3 s−1. The strain rate sensitivity exponent and the activation energy for deformation were estimated to be 0.884 and 91.9 kJ/mol, respectively. This indicates that the rate-controlling deformation mechanism under the aforementioned condition is grain boundary sliding controlled by lattice diffusion. Experimental cavity observations show the existence of cavity interlinkage or stringers. A new plasticity-controlled cavity growth rate equation considering cavity interlinkage was established, and a cavity growth diagram was constructed. The diagram prediction is consistent with the experimental results. In addition, fractographs show that the intergranular fracture is a ductile fracture mechanism. At room temperature, the ultimate tensile strength of 242 MPa and the elongation of 23.59% were obtained in the present alloy. © 2017 Elsevier B.V.


Li X.,Polytechnic University of Mozambique | Wang J.,Polytechnic University of Mozambique | Liu J.,Polytechnic University of Mozambique | Zhou Z.,Xian Supercrystal Science and Technology Development Co. | And 2 more authors.
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2016

The investment casting of complex multi-hole thin-wall structure parts of 00Cr18Ni10N alloy was simulated by using ProCAST software. The possible defects in filling and solidification process were predicted. The optimized parameters of investment casting are presented as follows: shell preheating at 800℃, pouring at 1 650℃, filling pressure of 0.4 Pa and filling velocity of 0.8 m/s. Optimized heat treatment parameters are presented as follows: solid solution at 1 020℃ for 2.5 h and air-cooled, and then annealing at 900℃ for 1.5 h +air-cooled. The results reveal that the investment castings exhibit desirable appearance with uniform chemical composition and absence of obvious defects such as porosity and shrinkage. Tensile strength, yield strength and elongation of the investment castings are increased technical requirements by 8.29%, 3.86% and 80%, respectively. © 2016, Journal Office of Special Casting and Nonferrous Alloys. All right reserved.


Zhou Z.,Xian supercrystal science and technology development Co. | Kou H.,Northwestern Polytechnical University | Xue X.,Xian supercrystal science and technology development Co. | Xue X.,Northwestern Polytechnical University | And 4 more authors.
Advanced Materials Research | Year: 2013

The energetic and electronic structure of α-type Ti1-xXx(X=Al and Zr, x=0.0625, 0.125, 0.185, 0.250, 0.3125and 0.375) binary alloys were calculated by the method of supercell and augmented plane waves plus local orbitals within generalized gradient approximation. The results show that the formation energy decreases with the composition of Al, while increases with composition of Zr, which indicate that α phase can be enhanced by increasing the Al contents while weaken by increasing Zr contents. The DOS results shows that the Fermi levels of Ti1-xAlxand Ti1-xZrxfall on a dip of a DOS curve, which means the α structure of these alloys is stable. When the Al content is increased, the charge transfer between the Al and its neighbors becomes more evident, and enhance the stability of the α phase. With an increase of Zr content, repulsive interaction between two Ti atoms strengthen, which result in the α phase stability decrease. © (2013) Trans Tech Publications, Switzerland.


Zhang L.-J.,Xian Super Crystal Science and Technology Development Co. | Zhou Z.-B.,Xian Super Crystal Science and Technology Development Co. | Chang H.,Xian Super Crystal Science and Technology Development Co. | Chang H.,Northwestern Polytechnical University | And 5 more authors.
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals | Year: 2013

The radiographic test, OM, SEM and EDS were adopted to study the segregation behavior of the β titanium alloy which possesses high molybdenum content. The results show that, the black spots in the ingot and rolling bar from 1/2 radius to the central regions are α flecks. The EDS results shows that the α flecks are lack of Mo element. The standard microstructure of the rolling bar after solution heat treatment is single β phase. A lot of unchanged fine α phase particles gather in the grey black segregation zone, so, the spot shows grey black under low magnification inspection.


Zhang L.,Xian Super Crystal Science and Technology Development Co. | Xue X.,Xian Super Crystal Science and Technology Development Co. | Xue X.,Northwestern Polytechnical University | Zheng Y.,Xian Super Crystal Science and Technology Development Co. | And 4 more authors.
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2013

Dissimilar metal composite 316L stainless steel/copper composites joint was prepared by a high-temperature vacuum dipping preparation, and the microstructures, tensile properties at room and low temperature, thermal fatigue properties of the copper dissimilar metals composite joints prepared were investigated. The results show that the 316L stainless steel/copper dissimilar metals composite joints prepared exhibit excellent room and low temperature performance as well as desirable thermal fatigue resistant property.


Wang L.,Chongqing University | Zhang X.,Chongqing University | Xue X.,Xian Supercrystal Science and Technology Development Co. | Wen H.,Xian Supercrystal Science and Technology Development Co. | Li Z.,Northwest Institute for Nonferrous Metal Research
Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering | Year: 2013

The microstructure and texture evolution of Zirconium tubes extruded at different temperatures have been investigated using X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) technology. The results show that dynamic recovery and recrystallization occurred in the hot-extruded tubes. The microstructure consists of sub-grains containing small angle boundary and equiaxed grains. The temperature has no effect on the mean size of equiaxed grains. However, there is wide difference in texture at different temperatures. The texture component of the tube extruded at 650°C consists of <101̄0> fiber and {0001}<101̄0>, while the texture component is <112̄0> fiber and {0001}<112̄0> with more basal poles in the tangential direction for the tube extruded at 630°C. Copyright © 2013, Northwest Institute for Nonferrous Metal Research. Published by Elsevier BV. All rights reserved.


Zhou Z.,Northwestern Polytechnical University | Zhang L.,Xian Supercrystal Science and Technology Development Co. | Chen Y.,Northwestern Polytechnical University | Kou H.,Northwestern Polytechnical University | And 3 more authors.
Ti 2011 - Proceedings of the 12th World Conference on Titanium | Year: 2012

Certain applications may require high-strength titanium fastener with a combination of high tensile strength,shear strength and fatigue strength. Over the past few years, the study of the relationship between the heat treatment parameter and the tension strength or fatigue strength in titanium alloy has achieved a strong development But there has little information on the shear strength. In this work,β21s titanium alloy has been adopted to investigate the characteristics of aging treatment on the shear strength. The results show that the longer the aging holding time is, the lesser of α phase amount becomes. Hence, the higher aging temperature results in a decrease in shear strength. The SEM images reveal that the a precipitates were slightly coarser after long holding times during aging treatment. As a result, the shear strength increases. An additional investigation in this study is about the effect of the specimen's dimension on the shear strength. It is showed that with the increase of the specimen' s dimension, the double-shear strength decreases.


Zhu L.,Army Air Force Stationed in Zhengzhou Representative Office | Zhang L.,Xian Super Crystal Science and Technology Development Co. | Guo K.,Xian Super Crystal Science and Technology Development Co. | Shao B.,Xian Super Crystal Science and Technology Development Co.
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2015

The effects of heat treatment on the microstructure and mechanical properties of β21s alloy sheets were investigated by using optical microscope and tensile tester. The results show that the alloy after solution treatment at 815~845 ℃ has a moderate strength and an excellent ductility at the room temperature, and with the increase of solution temperature, strength is decreased and plasticity is increased. After aging treatment, alloy exhibits high strength and good plasticity, and with the increase of aging temperature, the strength is decreased with the increase of plasticity. ©, 2015, Journal Office of Special Casting and Nonferrous Alloys. All right reserved.


Zhang L.,XiAn Super Crystal Science and Technology Development Co. | Bai Y.,XiAn Super Crystal Science and Technology Development Co. | Zhou Z.,XiAn Super Crystal Science and Technology Development Co. | Zhou Z.,Northwestern University | And 6 more authors.
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2011

New VAR process for preparing TB8 Ti alloy with high molybdenum content was presented. Firstly, commercial pure Mo powder was directly added into the alloy to prepare TB8 alloy ingot, and then based on using proper raw material and optimized VAR parameters, TB8 alloy ingot with high Mo content was prepared successfully. The alloy ingot was examined at different locations by composition testing and microstructure observation as well as XRD analysis. The results show that the alloy ingot exhibits homogeneous composition distribution, and the absence of inclusion and segregation of Mo element can be observed. The new VAR process is greatly superior to conventional process in raw material cost, quality cost and product cost.


Zhang L.,Xian Super Crystal Science and Technology Development Co. | Wang X.,Xian Super Crystal Science and Technology Development Co. | Chang H.,Xian Super Crystal Science and Technology Development Co. | Chang H.,Northwestern Polytechnical University | And 3 more authors.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2013

Effects of solution temperature on microstructure and mechanical properties of TB8 titanium alloy were studied. The results show that, with solution temperature increasing, β grains grow up obviously, strength decreases slightly and plastic gradually increases. After solutiong and aging treatment, a lot of α phase is homogeneous precipitated from the grain boundary and grain interior of β, strength increases and plasticity decreases. The alloy has high strength and good plasticity after soulationed at 770-830°C, and aged at 520°C, comprehensive properties of the alloy is excellent, σb>1300 MPa, δ>15%, Ψ>55%.

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