Mo fibers were added to RMC with different mass ratios of resin and hardener to improve its mechanical properties. The influences of fiber surface state and hardener content on interface bonding strength and mechanica...Mo fibers were added to RMC with different mass ratios of resin and hardener to improve its mechanical properties. The influences of fiber surface state and hardener content on interface bonding strength and mechanical properties of RMC were studied, respectively. Furthermore, strain values of typical measuring points on samples of Mo fiber reinforced RMC(MFRRMC) under different loads were obtained by experiments and finite element analysis. The experimental results prove that scrap Mo fibers can improve interface bonding strength and mechanical properties of RMC better than new smooth Mo fibers because of the discharge pits randomly distributed on the surface of scrap fibers. With the decrease of hardener content, not only interface bonding strength between fiber and matrix, but also compression and flexural strength of MFRRMC increase firstly and then decrease. The properties are best while the mass ratio of resin and hardener reaches 4:1. It is indicated that finite element calculation data basically agree with experimental data by comparison of strain values on typical measuring points, which can provide an important intuitive reference for successive study on other mechanical properties of MFRRMC, validating the correctness of simulation method as well.展开更多
Composite reinforced with continuous Mo fiber reinforcement was prepared by pre placing fiber and vacuum casting. The microstructure, concentration and hardness profiles across the interface in as cast and HIPed sampl...Composite reinforced with continuous Mo fiber reinforcement was prepared by pre placing fiber and vacuum casting. The microstructure, concentration and hardness profiles across the interface in as cast and HIPed samples were investigated. The results showed that the interfacial phases formed between Mo fiber and TiAl matrix in both materials. These include two intermetallic phases, ρ (Ti, Mo) 3Al and β (Ti, Mo)Al with a sequence of Mo ρ β γ (or γ+α 2). Boundaries of Mo/ ρ , and ρ/β are smooth, while the β/γ+α 2 interfaces are serrated with the serration parallel to the lamellar laths in the casting condition. The serration disappeared after HIPing, and the boundary between β and γ becomes smooth. The area containing ρ (Ti, Mo) 3Al and β (Ti, Mo)Al is harder than the TiAl matrix and the Mo fiber. Mo atoms appear to diffuse faster in α 2 Ti 3Al than in γ TiAl.展开更多
The immobilization of titanium dioxide （TiO2） on activated carbon fiber （ACF）, （TiO2/ACF）, was accomplished by sol-gel-adsorption method followed by calcination at temperatures varying from 300 to 600℃ in an ar...The immobilization of titanium dioxide （TiO2） on activated carbon fiber （ACF）, （TiO2/ACF）, was accomplished by sol-gel-adsorption method followed by calcination at temperatures varying from 300 to 600℃ in an argon atmosphere. The material properties were determined by scanning electron microscope （SEM）, X-ray diffraction （XRD） and nitrogen adsorption. The photodegradation behavior of TiO2 /ACF was investigated in aqueous solutions using phenol and methyl orange （MO） as target pollutants. The effects of calcination temperature, photocatalyst dosage, initial solution pH and radiation time on the degradation of organic pollutants were studied. It was found that organic pollutants could be removed rapidly from water by the TiO2/ACF photocatalyst and the sample calcined at 500℃ exhibited the highest removal efficiency. Kinetics analysis showed that the photocatalytic degradation reaction can be described by a first-order rate equation. In addition, the possibility of cyclic usage of the photocatalyst was also confirmed. Moreover, TiO2 is tightly bound to ACF and can be easily handled and recovered from water. It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.展开更多
基金Funded by the National Natural Science Foundation of China(No.5117 5308)the National Science and Technology Major Project of China(No.2012ZX04010032)
文摘Mo fibers were added to RMC with different mass ratios of resin and hardener to improve its mechanical properties. The influences of fiber surface state and hardener content on interface bonding strength and mechanical properties of RMC were studied, respectively. Furthermore, strain values of typical measuring points on samples of Mo fiber reinforced RMC(MFRRMC) under different loads were obtained by experiments and finite element analysis. The experimental results prove that scrap Mo fibers can improve interface bonding strength and mechanical properties of RMC better than new smooth Mo fibers because of the discharge pits randomly distributed on the surface of scrap fibers. With the decrease of hardener content, not only interface bonding strength between fiber and matrix, but also compression and flexural strength of MFRRMC increase firstly and then decrease. The properties are best while the mass ratio of resin and hardener reaches 4:1. It is indicated that finite element calculation data basically agree with experimental data by comparison of strain values on typical measuring points, which can provide an important intuitive reference for successive study on other mechanical properties of MFRRMC, validating the correctness of simulation method as well.
文摘Composite reinforced with continuous Mo fiber reinforcement was prepared by pre placing fiber and vacuum casting. The microstructure, concentration and hardness profiles across the interface in as cast and HIPed samples were investigated. The results showed that the interfacial phases formed between Mo fiber and TiAl matrix in both materials. These include two intermetallic phases, ρ (Ti, Mo) 3Al and β (Ti, Mo)Al with a sequence of Mo ρ β γ (or γ+α 2). Boundaries of Mo/ ρ , and ρ/β are smooth, while the β/γ+α 2 interfaces are serrated with the serration parallel to the lamellar laths in the casting condition. The serration disappeared after HIPing, and the boundary between β and γ becomes smooth. The area containing ρ (Ti, Mo) 3Al and β (Ti, Mo)Al is harder than the TiAl matrix and the Mo fiber. Mo atoms appear to diffuse faster in α 2 Ti 3Al than in γ TiAl.
基金supported by the Education Bureau Foundationn of Liaoning Province (No. 2008573) the Doctor Foundation of Shenyang Institute of Chemical Technology (No. 20063202)
文摘The immobilization of titanium dioxide （TiO2） on activated carbon fiber （ACF）, （TiO2/ACF）, was accomplished by sol-gel-adsorption method followed by calcination at temperatures varying from 300 to 600℃ in an argon atmosphere. The material properties were determined by scanning electron microscope （SEM）, X-ray diffraction （XRD） and nitrogen adsorption. The photodegradation behavior of TiO2 /ACF was investigated in aqueous solutions using phenol and methyl orange （MO） as target pollutants. The effects of calcination temperature, photocatalyst dosage, initial solution pH and radiation time on the degradation of organic pollutants were studied. It was found that organic pollutants could be removed rapidly from water by the TiO2/ACF photocatalyst and the sample calcined at 500℃ exhibited the highest removal efficiency. Kinetics analysis showed that the photocatalytic degradation reaction can be described by a first-order rate equation. In addition, the possibility of cyclic usage of the photocatalyst was also confirmed. Moreover, TiO2 is tightly bound to ACF and can be easily handled and recovered from water. It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.
