Fujian Longxi Bearing Group Corporation

Zhangzhou, China

Fujian Longxi Bearing Group Corporation

Zhangzhou, China
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Liu B.,Fujian Longxi Bearing Group Corporation Ltd. | Liu B.,Central South University | Zeng F.,Fujian Longxi Bearing Group Corporation Ltd. | Lu J.,Fujian Longxi Bearing Group Corporation Ltd. | And 3 more authors.
Fenmo Yejin Cailiao Kexue yu Gongcheng/Materials Science and Engineering of Powder Metallurgy | Year: 2016

Ti-45Al-7Nb-1B alloy reinforced by nano TiB wiskers was synthesized through spark plasma sintering (SPS) using Ti-45Al, Nb, Al and TiB2 powders as raw materials. The deformation behavior of the Ti-45Al-7Nb-1B alloy was studied in the temperature range of 900-1 200℃ and strain rate range of 0.001-1 s-1. A constitutive equation was derived using the Arrhenius hyperbolic sine function, and a processing map was constructed. The results show that the arrhenius hyperbolic sine function can well describe the deformation behavior of the Ti-45Al-7Nb-1B alloy. The activation energy is 497.95 kJ/mol. The material shows unstable flow when the strain rate is higher than 0.1 s-1, and the best processing window is 1 000-1 130℃/0.001-0.01 s-1. © 2016, Editorial Office of Materials Science and Engineering of Powder Metallurgy. All right reserved.


Cao Y.,Central South University | Zeng F.,Fujian Longxi Bearing Group Corporation | Lu J.,Fujian Longxi Bearing Group Corporation | Liu B.,Central South University | And 3 more authors.
Materials Transactions | Year: 2015

Titanium matrix composites reinforced with TiB whiskers were in situ synthesized by spark plasma sintering (SPS) at a temperature range of 11731473 K, using a mixture of 6.2 mass% TiB2, 4.1 mass% Ti, and 89.7 mass% Ti6Al4V powders. The in-situ synthesis mechanism and the effect of sintering temperature on the sintering microstructure were investigated. The results show that an increase of the sintering temperature causes the relative densities of the composites to increase and the reaction between Ti and TiB2 to be more complete. Nano-sized TiB reinforcements with a diameter of around 80 nm and fine-grained matrix with an average grain size of 12μm are obtained after SPSed at 1373 K. Clean and perfect TiB/matrix interfaces without debonding or cracks are obtained during SPS process. Low sintering temperature and short sintering time are believed to be the main reasons for the improved fine-grained microstructure. © 2015 The Japan Institute of Metals and Materials.


Patent
Xiamen University and Fujian Longxi Bearing Group Corporation | Date: 2014-11-05

A new approach for preparation and use of adhesive for metal and fabric bonding is proposed in this invention. Generally, 80-120 g of epoxy resin, 10-30 g of reactive diluent, 0.5-5 g siliane coupling agent, 0.5-5 g metallic oxide nanopowder and 35-60 g curing agent are applied in the formula. With the treatment of silane coupling agent and the mixture of phosphoric acid and nitric acid respectively, the active groups are introduced onto the surface of the metal and the fabric, which enhanced the adhesive strength of metal/fabric interface. Simultaneously, the brittleness, poor cracking and impact resistance of the traditional epoxy adhesive are also optimized by using the method of this invention, which is easy to operate and widely used.


Wang Y.,National University of Defense Technology | Fang X.,National University of Defense Technology | Zhang C.,Hunan Institute of Technology | Chen X.,National University of Defense Technology | Lu J.,Fujian Longxi Bearing Group Corporation Ltd
Eksploatacja i Niezawodnosc | Year: 2016

Due to small friction coefficient and no need for lubrication during operation, self-lubricating spherical plain bearings (SSPBs) have been widely used in operation and transmission systems in aerospace, nuclear power plants, and ship equipment and they are key components of these systems. SSPBs failure will directly affect the operational reliability and safety of the equipment; therefore, it is necessary to accurately predict the service life of SSPBs to define reasonable maintenance plans and replacement cycles and to ensure reliability and safety of vital equipment. So far, lifetime prediction of SSPB has been primarily based on empirical formulae established by most important bearing manufacturers. However, these formulae are lack of strong theoretical basis; the correction coefficients are difficult to determine, resulting in low accuracy of lifetime prediction. In an accelerated degradation test (ADT), the load is increased to accelerate the SSPB wear process. ADT provides a feasible way for accurate lifetime prediction of SSPB in a short period. In this paper, wear patterns are studied and methods of wear analysis are presented. Then, physics-offailure model which considers SSPB wear characteristics, structure parameters and operation parameters is established. Moreover, ADT method for SSPB is studied. Finally, lifetime prediction method of SSPBs based on physics-of-failure model and ADT is established to provide a theoretical method for quick and accurate lifetime prediction of SSPBs. © 2016, Polish Academy of Sciences Branch Lublin. All rights reserved.


Zhou C.,Central South University | Zeng F.P.,Fujian Longxi Bearing Group Corporation | Liu B.,Central South University | Liu Y.,Central South University | And 5 more authors.
Materials Transactions | Year: 2016

The effects of Si addition on microstructures, high temperature compressive properties and creep properties of the β-stabilized Ti-45Al-3Fe-2Mo alloy have been studied in this work. The results show that the Si addition decreases the volume fraction of β phase and precipitates particulate Ti5Si3 phase. At the same time, the Si addition improves the high temperature strength of the Ti-45Al-3Fe-2Mo alloy for about 200 MPa at 800°C and decreases the creep strain for about 35% at 800°C under an applied stress of 150 MPa. The decrease in volume fraction of β phase and precipitation of Ti5Si3 particles are believed to be the dominant mechanisms for the improvement of the high temperature properties of the Si-doped TiAl alloy. © 2016 The Japan Institute of Metals and Materials.


Liu B.,Fujian Longxi Bearing Group Corporation Ltd. | Liu B.,Central South University | Zeng F.-P.,Fujian Longxi Bearing Group Corporation Ltd. | Lu J.-Z.,Fujian Longxi Bearing Group Corporation Ltd. | And 2 more authors.
Fenmo Yejin Cailiao Kexue yu Gongcheng/Materials Science and Engineering of Powder Metallurgy | Year: 2015

Deformation behavior of the P/M pure titanium was studied in a temperature range of 400~700 ℃ and a strain rate range of 0.001~1 s-1. A constitutive equation was derived with arrhenius hyperbolic sine function and a processing map was constructed. The results show that arrhenius hyperbolic sine function can well describe the constitutive equation of the powder metallurgy (P/M) pure titanium. The activation energy is 221.23 kJ/mol. The material shows unstable flow when strain rate is higher than 0.1 s-1, and the best processing regions are 450~550 ℃/0.001~0.01 s-1 and 625~700 ℃/0.001~0.01 s-1. ©, 2015, Central South University. All right reserved.


Cao Y.,Central South University | Zeng F.,Fujian Longxi Bearing Group Corporation | Liu B.,Central South University | Liu B.,Fujian Longxi Bearing Group Corporation | And 4 more authors.
Materials Science and Engineering A | Year: 2016

The fatigue characteristics of powder metallurgy (P/M) Ti6Al4V (wt%) alloys prepared by powder sintering and hot rolling were studied under tension-tension loading conditions at R=0.1 and 25Hz in air, where R=σmin/σmax (σmin and σmax are the applied minimum and maximum stresses, respectively). The results show that for the as-sintered Ti6Al4V alloy the fatigue limit is about 325MPa, and the fatigue cracks initiate from the residual pores open to the surface of the gauge area and propagate along the α/β interfaces. Hot rolling markedly enhances the fatigue properties, and the fatigue limit increases to about 430MPa. The reducing of porosity and refining of grain size through hot rolling are the dominant mechanisms for the improvement of fatigue properties. In addition, the microstructure of α/β interfaces//RD and the texture of <0001>α//RD formed during hot rolling act as barriers for the fatigue crack propagation, which partly attributes to the improvement of the fatigue properties. © 2015 Elsevier B.V.


Chen Z.-X.,Central South University | Liu B.,Central South University | Liu B.,Fujian Longxi Bearing Group Corporation | Liu Y.,Central South University | And 2 more authors.
Journal of Central South University | Year: 2016

A titanium alloy containing continuous oxygen gradient was prepared by powder metallurgy (P/M) and the composition–property relationship was studied on a single sample. The alloy was sintered with layered powder of different oxygen contents via vacuum sintering and spark plasma sintering (SPS), respectively. After subsequent heat treatments, high-throughput characterizations of the microstructures and mechanical properties by localized measurements were conducted. The Ti-7% Mo (molar fraction) alloy with an oxygen content ranging from 1.3×10−3 to 6.2×10−5 (mass fraction) was obtained, and the effects of oxygen on the microstructural evolution and mechanical properties were studied. The results show that SPS is an effective way for fabricating fully dense Ti alloy with a compositional gradient. The average width of α′ phase coarsens with the increase of the content of oxygen. The content of α″ martensitic phase also increases with the content of oxygen. At oxygen contents of 3×10−3 and 4×10−3 (mass fraction), the Ti alloys present the lowest microhardness and the lowest elastic modulus, respectively. The results also indicate that the martensitic phases actually decrease the hardness of Ti-7Mo alloy, and oxygen effectively hardens the alloy by solid solution strengthening. Therefore, the high-throughput characterization on a microstructure with a gradient content of oxygen is an effective method for rapidly evaluating the composition–property relationship of titanium alloys. © 2016, Central South University Press and Springer-Verlag Berlin Heidelberg.

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