Mechanical properties and microstructures of Al-Li-Cu-Mg-Ag alloy after solution treatments were investigated by means of optical microscopy （OM）, tensile test, hardness measurement and electrical conductivity test,...Mechanical properties and microstructures of Al-Li-Cu-Mg-Ag alloy after solution treatments were investigated by means of optical microscopy （OM）, tensile test, hardness measurement and electrical conductivity test, differential scanning calorimetric （DSC）, energy dispersive X-ray （EDX）, scanning electron microscopy （SEM） and transition electron microscopy （TEM）, respectively The results show that both tensile strength and hardness increase first and then decrease with temperature at constant holding time of 30 min with maximum strength and hardness appearing at 520 ℃. Tensile strength, hardness and elongation of samples treated at 520 ℃ for 30 min are 566 MPa （σb）, 512 MPa （σ0.2）, HB 148 and 8.23% （δ）, respectively. There are certain amount of fine T1 （AI2CuLi） phase dispersing among AI substrates according to TEM images. This may result in mixed fracture morphology with trans-granular and inter-granular delamination cracks observed in SEM images.展开更多
The 800℃ isothermal section in the Al-Zn-Zr system was investigated using the equilibrated alloy method and the solid/liquid diffusion couple approach by means of scanning electron microscopy equipped with energy dis...The 800℃ isothermal section in the Al-Zn-Zr system was investigated using the equilibrated alloy method and the solid/liquid diffusion couple approach by means of scanning electron microscopy equipped with energy dispersive spectroscopy, X-ray powder diffraction and electron probe microanalysis. Thirteen three-phase regions are experimentally confirmed in the ternary system. A ternary compound Zn50Al25Zr25 named as T phase exists stably in the 800℃ isothermal section. Its composition range varies widely (16.84-55.1 at.% Zn, 18.02-56.3 at.% Al and 26.0-28.53 at.% Zr), and it can be in equilibrium with all the binary compounds. The maximum solubilities of Zn in Zr3Al, Zr2Al, Zr3Al2, Zr4Al3, ZrAl, Zr2Al3, ZrAl2 and ZrAl3 are 7.5, 0.84, 0.33, 0.89, 0.91, 1.12, 0.64 and 3.8 at.%, respectively. The maximum solubilities of Al in Zn3Zr, Zn2Zr and ZnZr are 1.6, 1.3 and 13.6 at.%, respectively.展开更多
A simple and practical method to calculate the fractal dimension （FD） of amicron＇s projective surface profile based on fractal theory is proposed. Taking AI（OH）3 material particles as an example, the scanning ele...A simple and practical method to calculate the fractal dimension （FD） of amicron＇s projective surface profile based on fractal theory is proposed. Taking AI（OH）3 material particles as an example, the scanning electron microscope （SEM） photos of particles were processed using an image.processing software （IPS） Photoshop. Taking the pixel as a fixed yardstick with the enlargement of the size of the particle image, the box-dimension and circumference-area （C-S） methods were used to calculate the FD of the surface profile of the particle. The FD of 1.2623 of the classic Koch curve is obtained, which approximates the true value of 1.2628. The complexities of the object＇s boundary and surface micro-topography are simulated successfully by a generator method.展开更多
To solve the problem of swelling and agglomeration of CaCl2 during the process of ammonia adsorption and improve the performance of mass transfer, we present a new method for the preparation of adsorbent. The CaCl2 is...To solve the problem of swelling and agglomeration of CaCl2 during the process of ammonia adsorption and improve the performance of mass transfer, we present a new method for the preparation of adsorbent. The CaCl2 is first immerged into sawdust by soaking method, then the composite adsorbent is prepared by carbonizing the mixture of CaCl2 and sawdust. The SEM image and elements analysis indicated that the new adsorbent has high porosity and uniform distribution of CaCl2 due to carbonization under temperature of 700℃. The performance testing of ammonia adsorption showed that under the conditions of evaporation temperature of -5℃ and condensation temperature of 40℃, the ammonia uptake reaches 0.204, 0.253 and 0.285 kg/kg, the specific cooling power （SCP） is 868.96, 540.02 and 405.16 W/kg, and the average adsorption rate is 6.79×10^-4, 4.22×10^-4 and 3.17×10^-4 kg/kg/s when the adsorption time is 5, 10 and 15 min, respectively. The problems of swelling and agglomeration of CaCl2 are solved.展开更多
In this paper, nano-porous A1N micro-rods were prepared and characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Brunauer-Emett-Teller （BET） met...In this paper, nano-porous A1N micro-rods were prepared and characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Brunauer-Emett-Teller （BET） method of nitrogen adsorption at low temperature, UV-via absorption spectrometry and Raman spectrometry. The SEM images and TEM images showed that the A1N samples were micro-size rods with pores in their surfaces evenly. The length of the rod was in the range of a few mi- crons to tens of micron, the diameter of the rods was about one micron, the diameter of the pore was about hundreds of nano- meter and the wall thickness of the pore about tens of nanometer. The BET surface area of the sample was 41.424 ma/g. The optical spectra showed that the optical properties of the A1N samples almost agreed with that of A1N bulk or film.展开更多
基金Foundation item： Project（6140506） supported by GAD （General Armament Department）, China
文摘Mechanical properties and microstructures of Al-Li-Cu-Mg-Ag alloy after solution treatments were investigated by means of optical microscopy （OM）, tensile test, hardness measurement and electrical conductivity test, differential scanning calorimetric （DSC）, energy dispersive X-ray （EDX）, scanning electron microscopy （SEM） and transition electron microscopy （TEM）, respectively The results show that both tensile strength and hardness increase first and then decrease with temperature at constant holding time of 30 min with maximum strength and hardness appearing at 520 ℃. Tensile strength, hardness and elongation of samples treated at 520 ℃ for 30 min are 566 MPa （σb）, 512 MPa （σ0.2）, HB 148 and 8.23% （δ）, respectively. There are certain amount of fine T1 （AI2CuLi） phase dispersing among AI substrates according to TEM images. This may result in mixed fracture morphology with trans-granular and inter-granular delamination cracks observed in SEM images.
基金Projects(51771160,51471140)supported by the National Natural Science Foundation of China
文摘The 800℃ isothermal section in the Al-Zn-Zr system was investigated using the equilibrated alloy method and the solid/liquid diffusion couple approach by means of scanning electron microscopy equipped with energy dispersive spectroscopy, X-ray powder diffraction and electron probe microanalysis. Thirteen three-phase regions are experimentally confirmed in the ternary system. A ternary compound Zn50Al25Zr25 named as T phase exists stably in the 800℃ isothermal section. Its composition range varies widely (16.84-55.1 at.% Zn, 18.02-56.3 at.% Al and 26.0-28.53 at.% Zr), and it can be in equilibrium with all the binary compounds. The maximum solubilities of Zn in Zr3Al, Zr2Al, Zr3Al2, Zr4Al3, ZrAl, Zr2Al3, ZrAl2 and ZrAl3 are 7.5, 0.84, 0.33, 0.89, 0.91, 1.12, 0.64 and 3.8 at.%, respectively. The maximum solubilities of Al in Zn3Zr, Zn2Zr and ZnZr are 1.6, 1.3 and 13.6 at.%, respectively.
基金Project 50474003 supported by the National Natural Science Foundation of China
文摘A simple and practical method to calculate the fractal dimension （FD） of amicron＇s projective surface profile based on fractal theory is proposed. Taking AI（OH）3 material particles as an example, the scanning electron microscope （SEM） photos of particles were processed using an image.processing software （IPS） Photoshop. Taking the pixel as a fixed yardstick with the enlargement of the size of the particle image, the box-dimension and circumference-area （C-S） methods were used to calculate the FD of the surface profile of the particle. The FD of 1.2623 of the classic Koch curve is obtained, which approximates the true value of 1.2628. The complexities of the object＇s boundary and surface micro-topography are simulated successfully by a generator method.
基金supported by the Chinese Academy of Sciences and Foreign Experts Bureau of Guangdong under the Adsorption Refrigeration Program (Grant nos. y007y51001 and 2010004)The structure and preparation process of the new adsorbent has a patent (China Patent 20111015-1114.2)
文摘To solve the problem of swelling and agglomeration of CaCl2 during the process of ammonia adsorption and improve the performance of mass transfer, we present a new method for the preparation of adsorbent. The CaCl2 is first immerged into sawdust by soaking method, then the composite adsorbent is prepared by carbonizing the mixture of CaCl2 and sawdust. The SEM image and elements analysis indicated that the new adsorbent has high porosity and uniform distribution of CaCl2 due to carbonization under temperature of 700℃. The performance testing of ammonia adsorption showed that under the conditions of evaporation temperature of -5℃ and condensation temperature of 40℃, the ammonia uptake reaches 0.204, 0.253 and 0.285 kg/kg, the specific cooling power （SCP） is 868.96, 540.02 and 405.16 W/kg, and the average adsorption rate is 6.79×10^-4, 4.22×10^-4 and 3.17×10^-4 kg/kg/s when the adsorption time is 5, 10 and 15 min, respectively. The problems of swelling and agglomeration of CaCl2 are solved.
基金supported by the National Natural Science Foundation of Shanxi Provincial Department of Education (Grant No. 2010JK744)the Key Academic Discipline Project of Shaanxi Province
文摘In this paper, nano-porous A1N micro-rods were prepared and characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Brunauer-Emett-Teller （BET） method of nitrogen adsorption at low temperature, UV-via absorption spectrometry and Raman spectrometry. The SEM images and TEM images showed that the A1N samples were micro-size rods with pores in their surfaces evenly. The length of the rod was in the range of a few mi- crons to tens of micron, the diameter of the rods was about one micron, the diameter of the pore was about hundreds of nano- meter and the wall thickness of the pore about tens of nanometer. The BET surface area of the sample was 41.424 ma/g. The optical spectra showed that the optical properties of the A1N samples almost agreed with that of A1N bulk or film.
