Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The ...Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K 2CO 3·3/2H 2O,Li 2 B 4O 7·3H 2O, K 2 B 4O 7 ·4H 2O and Li 2CO 3. The composition of the solution corresponding to E was w(CO 2- 3)=2.27 %, w(B 4O 2- 7) =6.05 %, w(K + ) =4.30%,w(Li + )=0.30 % and the equilibrium solids were Li 2 B 4O 7· 3H 2O+K 2 B 4O 7·4H 2O+Li 2CO 3;The composition of the solution for F was w(CO 2- 3) =22.45%,w(B 4O 2- 7)=1.88%,w(K + )=29.96%,w(Li + )=0.03% and the equilibrium solids were K 2CO 3·3/2H 2O+ K 2 B 4O 7·4H 2O+Li 2CO 3. K 2CO 3 possesses strong salting-out effect on K 2 B 4O 7,Li 2CO 3 and Li 2 B 4O 7.展开更多
To improve the wear resistance and corrosion resistance of magnesium alloys, a 5 kW continuous wave CO2 laser was used to investigate the laser surface cladding on AZ31 B magnesium alloys with Al-Si/Al2O3-TiO2 composi...To improve the wear resistance and corrosion resistance of magnesium alloys, a 5 kW continuous wave CO2 laser was used to investigate the laser surface cladding on AZ31 B magnesium alloys with Al-Si/Al2O3-TiO2 composite powders. A detailed microstructure, chemical composition, and phase analysis of the composite coatings were studied by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, and X-ray diffraction （XRD）. The laser cladding shows good metallurgical bonding with the substrate. The composite coatings are composed of Mgl7Al12, Al3Mg2, Mg2Si, Al2O3, and TiO2 phases. Compared to the average microhardness （50HV0.05） of the AZ3 1 B substrate, that of the composite coatings （230HV0.05） is improved significantly. The wear resistances of the surface layers were evaluated in detail. The results demonstrate that the wear resistances of the laser surface-modified samples are considerably improved compared to the substrate. It also show that the composite coatings exhibit better corrosion resistance than that of the substrate in 3.5wt% NaCI solution.展开更多
文摘Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K 2CO 3·3/2H 2O,Li 2 B 4O 7·3H 2O, K 2 B 4O 7 ·4H 2O and Li 2CO 3. The composition of the solution corresponding to E was w(CO 2- 3)=2.27 %, w(B 4O 2- 7) =6.05 %, w(K + ) =4.30%,w(Li + )=0.30 % and the equilibrium solids were Li 2 B 4O 7· 3H 2O+K 2 B 4O 7·4H 2O+Li 2CO 3;The composition of the solution for F was w(CO 2- 3) =22.45%,w(B 4O 2- 7)=1.88%,w(K + )=29.96%,w(Li + )=0.03% and the equilibrium solids were K 2CO 3·3/2H 2O+ K 2 B 4O 7·4H 2O+Li 2CO 3. K 2CO 3 possesses strong salting-out effect on K 2 B 4O 7,Li 2CO 3 and Li 2 B 4O 7.
基金Funded by the national Natural Science Foundation of China (No. 51075293)the Foundation for Development of Science and Technology of Taiyuan University of Technology,China(No.K201014)
文摘To improve the wear resistance and corrosion resistance of magnesium alloys, a 5 kW continuous wave CO2 laser was used to investigate the laser surface cladding on AZ31 B magnesium alloys with Al-Si/Al2O3-TiO2 composite powders. A detailed microstructure, chemical composition, and phase analysis of the composite coatings were studied by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, and X-ray diffraction （XRD）. The laser cladding shows good metallurgical bonding with the substrate. The composite coatings are composed of Mgl7Al12, Al3Mg2, Mg2Si, Al2O3, and TiO2 phases. Compared to the average microhardness （50HV0.05） of the AZ3 1 B substrate, that of the composite coatings （230HV0.05） is improved significantly. The wear resistances of the surface layers were evaluated in detail. The results demonstrate that the wear resistances of the laser surface-modified samples are considerably improved compared to the substrate. It also show that the composite coatings exhibit better corrosion resistance than that of the substrate in 3.5wt% NaCI solution.
