Volume 35,Issue 12,2006 Table of Contents
1 Numerical Simulation of Freckle Formation in Directional Solidification of Nickel-Based Superalloy
2006, 35(12):1849-1853.
Abstract:
A mathematical model was built to describe the transportation phenomena and the freckle formation during the solidification process of multicomponent Ni-base superalloy.A set of expressions of coupling liquidus and solid fraction as well as multicomponent concentrations was determined based on the pseudobinary phase diagram.The numerical simulation of Ni-5.8%Al-15.2%Ta(mass fraction)alloy during the vertically unidirectional solidification was performed by this continuum model.The results show that the model is reasonable to describe the formation and evolution of freckle in superalloy ingot.Freckles were significantly induced by the density inversion due to the thermosolutal convection in front of the solid/liquid interface.The solute-rich liquid in the channel flows from mush into liquid.In order to maintain the mass equilibrium in the channels,the fresh liquid may penetrate via the mushy zone from pure liquid region.The plumes appearing at the preliminary solidification stage were unstable and tended to converge.The stable channel was formed at the prior grown solidification front after the plumes were submerged.
A mathematical model was built to describe the transportation phenomena and the freckle formation during the solidification process of multicomponent Ni-base superalloy.A set of expressions of coupling liquidus and solid fraction as well as multicomponent concentrations was determined based on the pseudobinary phase diagram.The numerical simulation of Ni-5.8%Al-15.2%Ta(mass fraction)alloy during the vertically unidirectional solidification was performed by this continuum model.The results show that the model is reasonable to describe the formation and evolution of freckle in superalloy ingot.Freckles were significantly induced by the density inversion due to the thermosolutal convection in front of the solid/liquid interface.The solute-rich liquid in the channel flows from mush into liquid.In order to maintain the mass equilibrium in the channels,the fresh liquid may penetrate via the mushy zone from pure liquid region.The plumes appearing at the preliminary solidification stage were unstable and tended to converge.The stable channel was formed at the prior grown solidification front after the plumes were submerged.
2006, 35(12):1854-1858.
Abstract:
Based on gradient-dependent plasticity where an internal length parameter is included to consider the microstructural effect, the distributions of shear deformation, shear strain and temperature in adiabatic shear band were derived considering the slow and sharp decrease of load-carrying capacity beyond the peak shear stress. For Ti-6Al-4V, the distributions and evolutions of shear deformation, shear strain and temperature in shear band were calculated. In the band, the local plastic shear strain and temperature are highly nonuniform due to interactions and interplay among microstructures. The nonuniformity increases with the increase of imposed plastic shear strain. As flow shear stress decreases, the maximum plastic shear strain in the band linearly increases and the maximum temperature nonlineady increases. The prediction values of shear strain and temperature in shear band based on gradient-dependent plasticity are higher than those by use of classical elastoplastic theory. The present theoretical results on shear deformation and strain in shear band for Ti-6Al-4V are compared with the calculations according to previous high-speed photographs and the same tendencies are found. However, the theoretical prediction value of the maximum shear strain in the band is still lower than experimental measurement value.
Based on gradient-dependent plasticity where an internal length parameter is included to consider the microstructural effect, the distributions of shear deformation, shear strain and temperature in adiabatic shear band were derived considering the slow and sharp decrease of load-carrying capacity beyond the peak shear stress. For Ti-6Al-4V, the distributions and evolutions of shear deformation, shear strain and temperature in shear band were calculated. In the band, the local plastic shear strain and temperature are highly nonuniform due to interactions and interplay among microstructures. The nonuniformity increases with the increase of imposed plastic shear strain. As flow shear stress decreases, the maximum plastic shear strain in the band linearly increases and the maximum temperature nonlineady increases. The prediction values of shear strain and temperature in shear band based on gradient-dependent plasticity are higher than those by use of classical elastoplastic theory. The present theoretical results on shear deformation and strain in shear band for Ti-6Al-4V are compared with the calculations according to previous high-speed photographs and the same tendencies are found. However, the theoretical prediction value of the maximum shear strain in the band is still lower than experimental measurement value.
2006, 35(12):1859-1863.
Abstract:
The composite 85wt.%Mg-5wt.%Ni-10wt.%Ti19Cr50V22Mn9 was successfully prepared by mechanical alloying and its hydriding/dehydriding(H/D)properties were investigated by an isovolumetric method without any activation treatment.The effect of the milling time on the structure of the composite was measured by the X-ray diffraction,microscope and mastersizer technologies.The relationship between the technology and structure and properties was carefully analyzed.The composite can absorb and desorbe 6.70 wt.% and 6.6 wt.%,respectively,within 20 min at 573 K.Its H/D kinetic mechanism was studied and the results indicated that the rate-controlling step of the H/D processes is the diffusion of hydrogen,the very good agreement between the experimental results and calculated curves by a simple new kinetic model was presented.The activation energies were calculated to be 63 kJ?mol-1 for absorption and 69 kJ?mol-1 for desorption.
The composite 85wt.%Mg-5wt.%Ni-10wt.%Ti19Cr50V22Mn9 was successfully prepared by mechanical alloying and its hydriding/dehydriding(H/D)properties were investigated by an isovolumetric method without any activation treatment.The effect of the milling time on the structure of the composite was measured by the X-ray diffraction,microscope and mastersizer technologies.The relationship between the technology and structure and properties was carefully analyzed.The composite can absorb and desorbe 6.70 wt.% and 6.6 wt.%,respectively,within 20 min at 573 K.Its H/D kinetic mechanism was studied and the results indicated that the rate-controlling step of the H/D processes is the diffusion of hydrogen,the very good agreement between the experimental results and calculated curves by a simple new kinetic model was presented.The activation energies were calculated to be 63 kJ?mol-1 for absorption and 69 kJ?mol-1 for desorption.
2006, 35(12):1864-1868.
Abstract:
用压入蠕变的方法研究了AE42合金和在AE41合金中加入0．4％-1．2％Ca的（质量分数，下同）Mg-Al-RE-Ca合金的抗蠕变性能，并利用光学显微镜，XRD和SEM（带EDS）对合金蠕变前后的组织结构进行了分析。结果表明：随着Ca添加量的提高，Mg-Al-RE-Ca合金的压入抗蠕变性能也不断提高，Mg-Al-RE-Ca合金在150℃和175℃时的压入抗蠕变性能优于AE42合金。压入蠕变前后的组织结构分析表明：AE42合金中Al11Nd3相在高温下不稳定会分解，造成抗蠕变性能下降：而在稀土含量相对少的Mg-Al-RE-Ca合金中，形成热稳定性好的Al2Ca，改善了合金的抗蠕变性能。
用压入蠕变的方法研究了AE42合金和在AE41合金中加入0．4％-1．2％Ca的（质量分数，下同）Mg-Al-RE-Ca合金的抗蠕变性能，并利用光学显微镜，XRD和SEM（带EDS）对合金蠕变前后的组织结构进行了分析。结果表明：随着Ca添加量的提高，Mg-Al-RE-Ca合金的压入抗蠕变性能也不断提高，Mg-Al-RE-Ca合金在150℃和175℃时的压入抗蠕变性能优于AE42合金。压入蠕变前后的组织结构分析表明：AE42合金中Al11Nd3相在高温下不稳定会分解，造成抗蠕变性能下降：而在稀土含量相对少的Mg-Al-RE-Ca合金中，形成热稳定性好的Al2Ca，改善了合金的抗蠕变性能。
2006, 35(12):1869-1873.
Abstract:
选用0．3μm的Al2O3颗粒，制备了体积分数为30％的Al2O3P／2024Al复合材料。利用硬度测试，DSC测试，透射电镜等手段研究了亚微米Al2O3；2024Al复合材料在160℃，175℃和190℃3种温度下的时效硬化行为。结果表明：亚微米Al2O3颗粒的加入使复合材料的硬度显著提高，但时效前后复合材料硬度提高的幅度较基体合金低得多。利用DSC和TEM对时效过程的综合分析表明，亚微米Al2O3颗粒的加入抑制了GP区的形成，提高了S＇相的热扩散激活能，使S’相析出困难。表现为复合材料析出相的数量较少、尺寸较小。
选用0．3μm的Al2O3颗粒，制备了体积分数为30％的Al2O3P／2024Al复合材料。利用硬度测试，DSC测试，透射电镜等手段研究了亚微米Al2O3；2024Al复合材料在160℃，175℃和190℃3种温度下的时效硬化行为。结果表明：亚微米Al2O3颗粒的加入使复合材料的硬度显著提高，但时效前后复合材料硬度提高的幅度较基体合金低得多。利用DSC和TEM对时效过程的综合分析表明，亚微米Al2O3颗粒的加入抑制了GP区的形成，提高了S＇相的热扩散激活能，使S’相析出困难。表现为复合材料析出相的数量较少、尺寸较小。
2006, 35(12):1874-1878.
Abstract:
Based on Thomas-Fermi model, the effect of external electric field on inner boundary potential was studied and the new atomic potential boundary condition was established. Thomas-Fermi model was extended to solid solution and compound with the volume adding method. The entropy energy of various system was calculated and analyzed taking Al, Mg, Li, Cu, Au, Zn single atoms, Al-Mg solid solution and Mg5Al8 for instances. The results show that the entropy energy decreases first and then increases in the whole electric field; the trendline of entropy energy at the electrode voltage is mainly same as at the boundary potential in each system, but the trendline of entropy energy is different about zero point.
Based on Thomas-Fermi model, the effect of external electric field on inner boundary potential was studied and the new atomic potential boundary condition was established. Thomas-Fermi model was extended to solid solution and compound with the volume adding method. The entropy energy of various system was calculated and analyzed taking Al, Mg, Li, Cu, Au, Zn single atoms, Al-Mg solid solution and Mg5Al8 for instances. The results show that the entropy energy decreases first and then increases in the whole electric field; the trendline of entropy energy at the electrode voltage is mainly same as at the boundary potential in each system, but the trendline of entropy energy is different about zero point.
2006, 35(12):1879-1883.
Abstract:
PPy/rhBMP-2 composite coating on the pure Ti-substrate(Ti/PPy/rhBMP-2)has been successfully electrosynthesized by constant current method in aqueous media.The cyclic voltammetry demonstrated the redox reaction of the composite coating.125I radiolabeling technique was used to measure the amount of rhBMP-2 that was doped into Ti/PPy/rhBMP-2.Goniometer and SEM were used to characterize surface morphology.The effects of Ti/PPy/rhBMP-2 on the proliferation and differentiation of BMSCs were evaluated.The results indicated that rhBMP-2 could be incorporated into Ti/PPy/rhBMP-2 in the stable form of polyelectrolyte anion and the coating showed high roughness and loose structure.The doped rhBMP-2 can still keep the ability of osteoinduction and promote the proliferation and differentiation of BMSCs.
PPy/rhBMP-2 composite coating on the pure Ti-substrate(Ti/PPy/rhBMP-2)has been successfully electrosynthesized by constant current method in aqueous media.The cyclic voltammetry demonstrated the redox reaction of the composite coating.125I radiolabeling technique was used to measure the amount of rhBMP-2 that was doped into Ti/PPy/rhBMP-2.Goniometer and SEM were used to characterize surface morphology.The effects of Ti/PPy/rhBMP-2 on the proliferation and differentiation of BMSCs were evaluated.The results indicated that rhBMP-2 could be incorporated into Ti/PPy/rhBMP-2 in the stable form of polyelectrolyte anion and the coating showed high roughness and loose structure.The doped rhBMP-2 can still keep the ability of osteoinduction and promote the proliferation and differentiation of BMSCs.
2006, 35(12):1884-1887.
Abstract:
Ga base region was formed using low concentration doping-junction depth process-high concentration doping method, and the NPN transistor sample was prepared. The experimental result and the theoretical analysis indicate that the linear slowacting distribution of Ga and diffusion under SiO2 film strongly heighten the withstand voltage level and all round electrical performance; negative-resistance effects in IC-VCE curve is caused by the concentration of Ga of the former surface becoming exhausted state by reoxidation. It can be improved with Si3N4/SiO2/Si composite structure; In brief, tube-open diffusion of Ga is a unexampled new approach to prepare high voltage device.
Ga base region was formed using low concentration doping-junction depth process-high concentration doping method, and the NPN transistor sample was prepared. The experimental result and the theoretical analysis indicate that the linear slowacting distribution of Ga and diffusion under SiO2 film strongly heighten the withstand voltage level and all round electrical performance; negative-resistance effects in IC-VCE curve is caused by the concentration of Ga of the former surface becoming exhausted state by reoxidation. It can be improved with Si3N4/SiO2/Si composite structure; In brief, tube-open diffusion of Ga is a unexampled new approach to prepare high voltage device.
2006, 35(12):1888-1891.
Abstract:
The plastic deformation in tungsten carbide plays an important role in the improvement of toughness of cemented carbide. Twining is one of typical ways of plastic deformation. The microstructure and twin deformation proporties of WC phases were investigated by loading alloy specimen. The results show that when WC phase is pure phase, it can generate twin-slip coordination deformation, thus the alloy exhibits higher toughness. And this kind of alloy is possessed of excellent properties during operation, especially in the fields of rock drilling.
The plastic deformation in tungsten carbide plays an important role in the improvement of toughness of cemented carbide. Twining is one of typical ways of plastic deformation. The microstructure and twin deformation proporties of WC phases were investigated by loading alloy specimen. The results show that when WC phase is pure phase, it can generate twin-slip coordination deformation, thus the alloy exhibits higher toughness. And this kind of alloy is possessed of excellent properties during operation, especially in the fields of rock drilling.
2006, 35(12):1892-1895.
Abstract:
采用热力学计算法、扩散偶法以及差示扫描量热法（DSC）对Mg-B体系成相行为进行了研究。热力学计算显示，Mg-B体系固-固反应在298K-923K温度范围内均可以发生。扩散研究显示，Mg-B之间的固态反应是通过Mg向B扩散实现的。DSC研究表明，Mg-B体系在升温过程中，分别在527．12℃，650．73℃和660．82℃，先后发生了固．固反应，Mg熔化以及液-固反应。在综合考虑扩散研究、热力学研究结果的基础上，提出了MS-B体系反应模型。
采用热力学计算法、扩散偶法以及差示扫描量热法（DSC）对Mg-B体系成相行为进行了研究。热力学计算显示，Mg-B体系固-固反应在298K-923K温度范围内均可以发生。扩散研究显示，Mg-B之间的固态反应是通过Mg向B扩散实现的。DSC研究表明，Mg-B体系在升温过程中，分别在527．12℃，650．73℃和660．82℃，先后发生了固．固反应，Mg熔化以及液-固反应。在综合考虑扩散研究、热力学研究结果的基础上，提出了MS-B体系反应模型。
2006, 35(12):1896-1899.
Abstract:
研究了低氧分压气氛中，不同熔化处理温度下单芯银包套带材（Bi，Pb）-2223（以下称Bi-2223）芯部熔化分解及随后的缓慢冷却阶段，淬火试样中Bi-2223，Bi-2201和Bi-2212相之间的演变关系。结果显示，在Tp=855℃-865℃范围内，随着熔化处理温度（Tp）的升高，淬火带材中Bi-2223相相对含量逐渐减少，而Bi-2201相含量则明显增加。Tp=855℃-860℃时，Bi-2223相发生部分分解，其淬火后的主要产物为Bi-2201，（Sr,Ca）2CuO3（2：1AEC）和（Sr,Ca）14Cu24O41（14：24AEC）。经过随后的缓慢冷却，部分分解的Bi-2223相可以直接从液相中再形成。在所有熔化试样及部分熔化后慢冷所得的试样中均未发现Bi-2212相。当Tp=865℃时，Bi-2223相则全部分解，在同样冷却条件下，其回复过程经历了两个不同的途径，一是少量Bi-2223相直接从液相中生成，二是先从液相中析出Bi-2212相，在随后继续冷却过程中再转变为Bi-2223相。由于Bi-2212转变为Bi-2223所固有的迟缓特性，以致在本实验的冷却条件下，完全分解的Bi-2223相只能部分得到回复。
研究了低氧分压气氛中，不同熔化处理温度下单芯银包套带材（Bi，Pb）-2223（以下称Bi-2223）芯部熔化分解及随后的缓慢冷却阶段，淬火试样中Bi-2223，Bi-2201和Bi-2212相之间的演变关系。结果显示，在Tp=855℃-865℃范围内，随着熔化处理温度（Tp）的升高，淬火带材中Bi-2223相相对含量逐渐减少，而Bi-2201相含量则明显增加。Tp=855℃-860℃时，Bi-2223相发生部分分解，其淬火后的主要产物为Bi-2201，（Sr,Ca）2CuO3（2：1AEC）和（Sr,Ca）14Cu24O41（14：24AEC）。经过随后的缓慢冷却，部分分解的Bi-2223相可以直接从液相中再形成。在所有熔化试样及部分熔化后慢冷所得的试样中均未发现Bi-2212相。当Tp=865℃时，Bi-2223相则全部分解，在同样冷却条件下，其回复过程经历了两个不同的途径，一是少量Bi-2223相直接从液相中生成，二是先从液相中析出Bi-2212相，在随后继续冷却过程中再转变为Bi-2223相。由于Bi-2212转变为Bi-2223所固有的迟缓特性，以致在本实验的冷却条件下，完全分解的Bi-2223相只能部分得到回复。
2006, 35(12):1900-1903.
Abstract:
Ti40 burn resistant titanium alloy shows excellent burn-resistance performance and good mechanical properties at room temperature. However, it is easy to crack because of low ductility at high temperature, especially during the ingot cogging procedure. An important concern in forming is whether or not the desired deformation can be accomplished without failure of this alloy. This paper described the utilization of ductile fracture criteria in conjunction with the finite element method for predicting failures in hot forming processes of Ti40 alloy. Cylindrical specimens under compression tests at different deformed temperatures and strain rates were experimentally investigated. It is found that the alloy exhibited longitudinal cracking and shear cracking at some conditions of deformation. Subsequently, the finite element numerical simulation of the tests obtained local stress-strain history, which was used to evaluate six previously published ductile fracture criteria for predicting the accuracies of the fracture initiation locations of Ti40 alloy in hot forming. It is proved that only Oyane et al. ductile fracture criteria can accurately predict the initial location of fracture and the damage of Ti40 alloy for all the tests performed in this work.
Ti40 burn resistant titanium alloy shows excellent burn-resistance performance and good mechanical properties at room temperature. However, it is easy to crack because of low ductility at high temperature, especially during the ingot cogging procedure. An important concern in forming is whether or not the desired deformation can be accomplished without failure of this alloy. This paper described the utilization of ductile fracture criteria in conjunction with the finite element method for predicting failures in hot forming processes of Ti40 alloy. Cylindrical specimens under compression tests at different deformed temperatures and strain rates were experimentally investigated. It is found that the alloy exhibited longitudinal cracking and shear cracking at some conditions of deformation. Subsequently, the finite element numerical simulation of the tests obtained local stress-strain history, which was used to evaluate six previously published ductile fracture criteria for predicting the accuracies of the fracture initiation locations of Ti40 alloy in hot forming. It is proved that only Oyane et al. ductile fracture criteria can accurately predict the initial location of fracture and the damage of Ti40 alloy for all the tests performed in this work.
2006, 35(12):1904-1907.
Abstract:
Strengthening mechanism of Au990-Ti jewelry alloys has been studied systematically bY means of tensile test, hardness test, optical microscopic analysis. Results show that strengthening modes of Au990-Ti jewelry alloys mainly cover grain refining strengthening, work hardening and aging strengthening, and that their mechanical properties are superior to those of standard An917 jewelry alloys, that is, An917Ag55Cu28 and Au917Ag32Cu51. In addition, Au990-Ti jewelry alloys are of better cold workability than pure gold, because of high hardness and strength, good ductility in the solid solution state.
Strengthening mechanism of Au990-Ti jewelry alloys has been studied systematically bY means of tensile test, hardness test, optical microscopic analysis. Results show that strengthening modes of Au990-Ti jewelry alloys mainly cover grain refining strengthening, work hardening and aging strengthening, and that their mechanical properties are superior to those of standard An917 jewelry alloys, that is, An917Ag55Cu28 and Au917Ag32Cu51. In addition, Au990-Ti jewelry alloys are of better cold workability than pure gold, because of high hardness and strength, good ductility in the solid solution state.
2006, 35(12):1908-1911.
Abstract:
采用静态高压釜实验研究了NZ2合金在360℃，18．6MPa含Li水和400℃，10．3MPa蒸汽中的腐蚀动力学，通过X射线衍射法研究了NZ2合金在两种介质中腐蚀不同时间后氧化膜的晶体结构。结果表明：NZ2合金在360℃含Li水中腐蚀速率较400℃蒸汽中的低；随着腐蚀时间的延长，氧化膜中四方氧化锆含量逐渐降低，单斜氧化锆含量逐渐增高，四方氧化锆向单斜氧化锆转变。腐蚀转折时，氧化膜中出现了立方氧化锆，随后氧化膜中立方相含量明显增多，说明四方相向单斜相转变过程中，立方相是作为过渡相存在。氧化膜中四方相含量越高，腐蚀速率越低。
采用静态高压釜实验研究了NZ2合金在360℃，18．6MPa含Li水和400℃，10．3MPa蒸汽中的腐蚀动力学，通过X射线衍射法研究了NZ2合金在两种介质中腐蚀不同时间后氧化膜的晶体结构。结果表明：NZ2合金在360℃含Li水中腐蚀速率较400℃蒸汽中的低；随着腐蚀时间的延长，氧化膜中四方氧化锆含量逐渐降低，单斜氧化锆含量逐渐增高，四方氧化锆向单斜氧化锆转变。腐蚀转折时，氧化膜中出现了立方氧化锆，随后氧化膜中立方相含量明显增多，说明四方相向单斜相转变过程中，立方相是作为过渡相存在。氧化膜中四方相含量越高，腐蚀速率越低。
2006, 35(12):1912-1915.
Abstract:
The effects of zirconium on the microstructure and mechanical properties of Mg-5Sn alloys were studied. It can be found that the grain of alloy is obviously refined with the addition of Zr. The mechanical properties experiments indicate that the tensile strength and especially the elongation of the alloys are improved gradually with rising of Zr content. The main reason is attributed to the grain refinement. The micro-hardness of the alloy changes little after the addition of Zr, which is due to no obvious appearance of the second hardening phases in the alloys.
The effects of zirconium on the microstructure and mechanical properties of Mg-5Sn alloys were studied. It can be found that the grain of alloy is obviously refined with the addition of Zr. The mechanical properties experiments indicate that the tensile strength and especially the elongation of the alloys are improved gradually with rising of Zr content. The main reason is attributed to the grain refinement. The micro-hardness of the alloy changes little after the addition of Zr, which is due to no obvious appearance of the second hardening phases in the alloys.
2006, 35(12):1916-1919.
Abstract:
The surface morphology,elements distribution at he interface between coating and matrix,accelerated life time test and failure mechanism were discussed under the conditions of different sublayer surface modifications for Ti/(IrO2+Ta2O5)anodes such as special surface treatment(SST),metal Ta and Pt modification.The results show that Ti based surface modification has no basal influence on the surface morphology,the anodes have very long term accelerated life time at the flat stage with different surface modifications.Electrolysis dissolve of oxides is the main failure mechanism for the anode at the flat stage starting from island banks.
The surface morphology,elements distribution at he interface between coating and matrix,accelerated life time test and failure mechanism were discussed under the conditions of different sublayer surface modifications for Ti/(IrO2+Ta2O5)anodes such as special surface treatment(SST),metal Ta and Pt modification.The results show that Ti based surface modification has no basal influence on the surface morphology,the anodes have very long term accelerated life time at the flat stage with different surface modifications.Electrolysis dissolve of oxides is the main failure mechanism for the anode at the flat stage starting from island banks.
2006, 35(12):1920-1923.
Abstract:
采用电弧熔炼法制备了4种不同成分的Mo-Si-B合金，利用XRD和SEM-BSE对其显微组织进行了分析，以及利用TGA，XRD和SEM-BSE对其在1200℃的氧化行为进行了研究。显微组织分析表明：4种合金均由Mo，Mo5SiB2（T2），Mo3Si三相组成。氧化结果显示：死相含量最多的合金有最好的抗氧化性；在Si含量相同的条件下，具有共晶组织的合金抗氧化性最好。氧化后的合金由表面氧化层、中间层和基体组成。对表面氧化层的相结构进行了XRD和BSE分析，发现表面氧化层主要由非晶SiO2组成。
采用电弧熔炼法制备了4种不同成分的Mo-Si-B合金，利用XRD和SEM-BSE对其显微组织进行了分析，以及利用TGA，XRD和SEM-BSE对其在1200℃的氧化行为进行了研究。显微组织分析表明：4种合金均由Mo，Mo5SiB2（T2），Mo3Si三相组成。氧化结果显示：死相含量最多的合金有最好的抗氧化性；在Si含量相同的条件下，具有共晶组织的合金抗氧化性最好。氧化后的合金由表面氧化层、中间层和基体组成。对表面氧化层的相结构进行了XRD和BSE分析，发现表面氧化层主要由非晶SiO2组成。
2006, 35(12):1924-1927.
Abstract:
The fracture characteristics of laser welded BT20 titanium alloy joints have been investigated through in-situ tensile tests in scanning electron microscope using a single-edge notched specimen. For as-welded specimens, they would fracture as soon as the crack initiated. The specimen after post-weld heat treatment experienced a long metastable stage before fracture. Microcrack initiated along slip band under the combination action of shear stress and normal stress. The crack would deflect when it came across slip bands. New microcrack would initiate at the position of slip bands intersecting each other ahead of the main crack, and converged with the main crack subsequently. Post-weld heat treatment can improve the toughness and plasticity of laser welded joints markedly.
The fracture characteristics of laser welded BT20 titanium alloy joints have been investigated through in-situ tensile tests in scanning electron microscope using a single-edge notched specimen. For as-welded specimens, they would fracture as soon as the crack initiated. The specimen after post-weld heat treatment experienced a long metastable stage before fracture. Microcrack initiated along slip band under the combination action of shear stress and normal stress. The crack would deflect when it came across slip bands. New microcrack would initiate at the position of slip bands intersecting each other ahead of the main crack, and converged with the main crack subsequently. Post-weld heat treatment can improve the toughness and plasticity of laser welded joints markedly.
19 Study on Adsorption Property of Rare Earth Elements by Myrtan Tannins Immodilized on Collagen Fiber
2006, 35(12):1928-1931.
Abstract:
以胶原纤维为基质，通过醛交联剂将杨梅单宁固化在胶原纤维上制备吸附材料。研究了该吸附材料对稀土元素Pr^3＋，Nd^3＋的吸附性能。结果表明：温度在293K～323K的范围内，Pr^3＋，Nd^3＋的吸附平衡量随温度的升高略有增加。pH值对吸附平衡量影响较大，在pH值为3．5-5．0范围内，吸附量随pH值升高而增加。当pH≥5．0时，吸附量开始逐渐下降。吸附动力学可用拟二级速率方程来描述，由拟二级速率方程计算所得到的吸附平衡量与实测值的偏差在6％以内。该吸附材料适合柱上操作，吸附柱也易于再生。
以胶原纤维为基质，通过醛交联剂将杨梅单宁固化在胶原纤维上制备吸附材料。研究了该吸附材料对稀土元素Pr^3＋，Nd^3＋的吸附性能。结果表明：温度在293K～323K的范围内，Pr^3＋，Nd^3＋的吸附平衡量随温度的升高略有增加。pH值对吸附平衡量影响较大，在pH值为3．5-5．0范围内，吸附量随pH值升高而增加。当pH≥5．0时，吸附量开始逐渐下降。吸附动力学可用拟二级速率方程来描述，由拟二级速率方程计算所得到的吸附平衡量与实测值的偏差在6％以内。该吸附材料适合柱上操作，吸附柱也易于再生。
2006, 35(12):1932-1935.
Abstract:
The effects of molybdenum addition on the sintering densification and mechanic properties of Ti-Mo alloy were investigated.The expansion/shrinkage characteristic of the alloy was analyzed by a dilatometer.The microstructure and mechanical properties of the alloy were studied by SEM and mechanical property measurement and test.The results show that the addition of Mo can't accelerate the sintering densification,but is beneficial to microstructure refining of Ti-Mo alloy.With increasing of Mo content,the microstructure refining is more and more obvious,resulting in great improving the ambient temperature plasticity of the alloy,the elongation of as-sintered Ti-Mo alloy can reach 23%.
The effects of molybdenum addition on the sintering densification and mechanic properties of Ti-Mo alloy were investigated.The expansion/shrinkage characteristic of the alloy was analyzed by a dilatometer.The microstructure and mechanical properties of the alloy were studied by SEM and mechanical property measurement and test.The results show that the addition of Mo can't accelerate the sintering densification,but is beneficial to microstructure refining of Ti-Mo alloy.With increasing of Mo content,the microstructure refining is more and more obvious,resulting in great improving the ambient temperature plasticity of the alloy,the elongation of as-sintered Ti-Mo alloy can reach 23%.
2006, 35(12):1936-1939.
Abstract:
采用硝酸盐热分解法合成了CaLa1-xAl3O7：xEu^3＋（0≤x≤1）粉末样品，研究了其在紫外和真空紫外激发下的发光特性及Eu^3＋掺杂量对CaLa1-xAl3O7：xEu^3＋发光强度的影响。XRD分析结果表明，当0≤x≤1时体系都能形成很好的单相。在254nm紫外（UV）激发下，其发射光谱由位于550nm～710nm几条锐线发射峰组成，以616nm处发射为主，当x=0．2时发射强度最高。在147nm真空紫外,（VUV）激发下，CaLa1-xAl3O7：xEu^3＋的发射光谱峰形与254nm（UV）激发下一致，当x=0．2时发射强度最高，但是强度较254nm（UV）激发下弱，表明UV和VUV激发下荧光体的发光机理不同。
采用硝酸盐热分解法合成了CaLa1-xAl3O7：xEu^3＋（0≤x≤1）粉末样品，研究了其在紫外和真空紫外激发下的发光特性及Eu^3＋掺杂量对CaLa1-xAl3O7：xEu^3＋发光强度的影响。XRD分析结果表明，当0≤x≤1时体系都能形成很好的单相。在254nm紫外（UV）激发下，其发射光谱由位于550nm～710nm几条锐线发射峰组成，以616nm处发射为主，当x=0．2时发射强度最高。在147nm真空紫外,（VUV）激发下，CaLa1-xAl3O7：xEu^3＋的发射光谱峰形与254nm（UV）激发下一致，当x=0．2时发射强度最高，但是强度较254nm（UV）激发下弱，表明UV和VUV激发下荧光体的发光机理不同。
2006, 35(12):1940-1942.
Abstract:
The isothermal section of Nb-Ti-Co ternary system rich in Co and Ti at 1173 K was determined by means of diffusion triple and electron microprobe analysis.The results indicate that there are six binary intermediate compounds formed:NbCo3,NbCo2,TiCo3,TiCo2,TiCo and Ti2Co.In this diffusion triple,Nb and Ti formed continuous solid solution,and no ternary compound was formed.There are six three-phase regions found at this temperature:(Co)+TiCo3+NbCo3,NbCo3+TiCo3+NbCo2,NbCo2+TiCo3+TiCo2,TiCo2+NbCo2+TiCo,NbCo2+TiCo+Ti2Co and NbCo2+Ti2Co+(Nb,Ti).
The isothermal section of Nb-Ti-Co ternary system rich in Co and Ti at 1173 K was determined by means of diffusion triple and electron microprobe analysis.The results indicate that there are six binary intermediate compounds formed:NbCo3,NbCo2,TiCo3,TiCo2,TiCo and Ti2Co.In this diffusion triple,Nb and Ti formed continuous solid solution,and no ternary compound was formed.There are six three-phase regions found at this temperature:(Co)+TiCo3+NbCo3,NbCo3+TiCo3+NbCo2,NbCo2+TiCo3+TiCo2,TiCo2+NbCo2+TiCo,NbCo2+TiCo+Ti2Co and NbCo2+Ti2Co+(Nb,Ti).
2006, 35(12):1943-1948.
Abstract:
研究了高温预析出对7A52合金组织、时效硬化和应力腐蚀断裂的影响。结果表明：高温预析出处理在保持7A52合金强度、塑性的同时，可提高合金抗应力腐蚀性能。480℃固溶处理条件下，经过预析出处理后，合金应力腐蚀开裂界限应力强度因子局KISCC由7．6MPa．m^1/2。提高至9．1MPa．m^1/2，475℃固溶处理条件下，经过预析出处理后，KISCC由8．9MPa．m^1/2。提高至11．1MPa．m^1/2;未经预析出处理的7A52合金应力腐蚀断裂区发生严重的阳极溶解腐蚀，晶界和亚晶界均发生断裂，经高温预析出处理后，应力腐蚀裂纹仅沿平行晶界扩展；高温预析出处理使晶界析出相粗化显著、离散度增大且晶界析出相Cu含量提高，这是合金抗应力腐蚀性能得到显著改善的重要原因。
研究了高温预析出对7A52合金组织、时效硬化和应力腐蚀断裂的影响。结果表明：高温预析出处理在保持7A52合金强度、塑性的同时，可提高合金抗应力腐蚀性能。480℃固溶处理条件下，经过预析出处理后，合金应力腐蚀开裂界限应力强度因子局KISCC由7．6MPa．m^1/2。提高至9．1MPa．m^1/2，475℃固溶处理条件下，经过预析出处理后，KISCC由8．9MPa．m^1/2。提高至11．1MPa．m^1/2;未经预析出处理的7A52合金应力腐蚀断裂区发生严重的阳极溶解腐蚀，晶界和亚晶界均发生断裂，经高温预析出处理后，应力腐蚀裂纹仅沿平行晶界扩展；高温预析出处理使晶界析出相粗化显著、离散度增大且晶界析出相Cu含量提高，这是合金抗应力腐蚀性能得到显著改善的重要原因。
2006, 35(12):1949-1953.
Abstract:
采用有机羟基酸络合-浸渍法制备了稀土钙钛矿型复合氧化物降氦助燃剂FP-DN，对其活性组分、载体进行了筛选，研究了过渡元素Cu的用量、活性组分负载量、以及焙烧温度对其催化性能的影响。实验结果表明，LSCMCx／γ-Al2O3系列催化剂，多余Cu量为0．2mol--0．5mol，负载量为10％--15％，焙烧温度为550℃--650℃时，催化剂对CO氧化，NO＋CO反应的综合催化性能最佳。稀土钙钛矿型复合氧化物降氮助燃剂在锦西重油催化裂化装置上的工业试验表明，其对二再烟气中NOx的脱除率可以达到92．01％。
采用有机羟基酸络合-浸渍法制备了稀土钙钛矿型复合氧化物降氦助燃剂FP-DN，对其活性组分、载体进行了筛选，研究了过渡元素Cu的用量、活性组分负载量、以及焙烧温度对其催化性能的影响。实验结果表明，LSCMCx／γ-Al2O3系列催化剂，多余Cu量为0．2mol--0．5mol，负载量为10％--15％，焙烧温度为550℃--650℃时，催化剂对CO氧化，NO＋CO反应的综合催化性能最佳。稀土钙钛矿型复合氧化物降氮助燃剂在锦西重油催化裂化装置上的工业试验表明，其对二再烟气中NOx的脱除率可以达到92．01％。
2006, 35(12):1954-1958.
Abstract:
The arc evolution and cathode spots of nanocomposite Ag-SnO2,Fe-doped nanocomposite Ag-SnO2 and commercial Ag-SnO2-In2O3 contact alloys were researched by high-speed camera and scanning electron microscopy(SEM).Experimental results show that the evolution of arc discharge in air can be divided into three stages:arc forming,steady burning of arc and attenuation.Compared with commercial Ag-SnO2-In2O3,after Fe doping,nanocomposite Ag-SnO2 contact has double time of arc forming and shorter time of steady burning.It also has more cathode spots corresponding arc roots which jump fast and have a larger motion region on the contact surfaces,as a result of the time of arc roots stay on the contact surfaces is shorter,and therefore the heat stream input cathode spots is decreased.After arc burning,the cathode spots are dispersive and melt is lighter,showing better characteristic of erosion resistant to arc.
The arc evolution and cathode spots of nanocomposite Ag-SnO2,Fe-doped nanocomposite Ag-SnO2 and commercial Ag-SnO2-In2O3 contact alloys were researched by high-speed camera and scanning electron microscopy(SEM).Experimental results show that the evolution of arc discharge in air can be divided into three stages:arc forming,steady burning of arc and attenuation.Compared with commercial Ag-SnO2-In2O3,after Fe doping,nanocomposite Ag-SnO2 contact has double time of arc forming and shorter time of steady burning.It also has more cathode spots corresponding arc roots which jump fast and have a larger motion region on the contact surfaces,as a result of the time of arc roots stay on the contact surfaces is shorter,and therefore the heat stream input cathode spots is decreased.After arc burning,the cathode spots are dispersive and melt is lighter,showing better characteristic of erosion resistant to arc.
2006, 35(12):1963-1966.
Abstract:
The Mg2Ni-1.0%Pd(mass fraction)alloy power was prepared by mechanical alloying.XRD and AFM analysis were used to identify the phase and microstructure of the powder milled for 20 h.The P-C-T curves and kinetics curves of Mg2Ni-1.0%Pd-H2/D2 system were measured.The results show that the particle size of Mg2Ni-1.0%Pd alloy powder prepared by mechanical alloying was between 10 nm~50 nm.Compared with the Mg2Ni alloy prepared by melting,the enthalpy of nanocrystalline Mg2Ni-1.0%Pd alloy decreased upon hydrogen absorption and increased upon hydrogen desorption.The alloy had a reversible storage capacity as high as 1.06(H/M,atom ratio).Compared with absorbing-desorbing H2,the plateaus pressure under the same temperature increased and the enthalpy decreased on the P-C-T curves of the alloy absorbing-desorbing D2.The isotope effects in nanocrystalline Mg2Ni-1.0%Pd-H2 and D2 interaction were noticeable.The rate curves of absorbing H2 and D2 were measured at different temperatures,and the relationship of the rate and temperature changed around 573 K.
The Mg2Ni-1.0%Pd(mass fraction)alloy power was prepared by mechanical alloying.XRD and AFM analysis were used to identify the phase and microstructure of the powder milled for 20 h.The P-C-T curves and kinetics curves of Mg2Ni-1.0%Pd-H2/D2 system were measured.The results show that the particle size of Mg2Ni-1.0%Pd alloy powder prepared by mechanical alloying was between 10 nm~50 nm.Compared with the Mg2Ni alloy prepared by melting,the enthalpy of nanocrystalline Mg2Ni-1.0%Pd alloy decreased upon hydrogen absorption and increased upon hydrogen desorption.The alloy had a reversible storage capacity as high as 1.06(H/M,atom ratio).Compared with absorbing-desorbing H2,the plateaus pressure under the same temperature increased and the enthalpy decreased on the P-C-T curves of the alloy absorbing-desorbing D2.The isotope effects in nanocrystalline Mg2Ni-1.0%Pd-H2 and D2 interaction were noticeable.The rate curves of absorbing H2 and D2 were measured at different temperatures,and the relationship of the rate and temperature changed around 573 K.
2006, 35(12):1967-1970.
Abstract:
Novel wear resistant alloys with metal silicide Ti5Si3 used as the reinforcing phase and intermetallic NiTi as the matrix were designed and fabricated by the laser melting process with different compositions of Ti-Ni-Si alloy powders. Microstructure, Vickers microhardness and dry-sliding wear resistance as a function of Ti5Si3 content were investigated. The results indicate that the as-solidified microstructure of the alloys transforms from hypoeutectic to eutectic and hypereutectic, respectively as the Ti5Si3 content increases. The reinforcing phase Ti5Si3 has a significant effect on the microhardness and the wear resistance of the alloys. The laser melted Ti5Si3/NiTi intermetallic alloys have excellent wear resistance under dry-sliding wear test conditions. Wear resistance of the intermetallic alloys is up to 40--90 times higher than the hardened ball-bearing steel GCr15 and increases noticeably with increasing of content of Ti5Si3 reinforceing phase. The excellent wear resistance of Ti5Si3/NiTi intermetallic alloys is attributed to the effective reinforcement of Ti5Si3 phase and the excellent toughness and pseudo-elasticity of NiTi phase.
Novel wear resistant alloys with metal silicide Ti5Si3 used as the reinforcing phase and intermetallic NiTi as the matrix were designed and fabricated by the laser melting process with different compositions of Ti-Ni-Si alloy powders. Microstructure, Vickers microhardness and dry-sliding wear resistance as a function of Ti5Si3 content were investigated. The results indicate that the as-solidified microstructure of the alloys transforms from hypoeutectic to eutectic and hypereutectic, respectively as the Ti5Si3 content increases. The reinforcing phase Ti5Si3 has a significant effect on the microhardness and the wear resistance of the alloys. The laser melted Ti5Si3/NiTi intermetallic alloys have excellent wear resistance under dry-sliding wear test conditions. Wear resistance of the intermetallic alloys is up to 40--90 times higher than the hardened ball-bearing steel GCr15 and increases noticeably with increasing of content of Ti5Si3 reinforceing phase. The excellent wear resistance of Ti5Si3/NiTi intermetallic alloys is attributed to the effective reinforcement of Ti5Si3 phase and the excellent toughness and pseudo-elasticity of NiTi phase.
28 Structures and Mechanical Properties of Ni-Co-Cr Based Superalloy Prepared by Technique of EB-PVD
2006, 35(12):1971-1974.
Abstract:
采用电子束物理气相沉积（EB-PVD）技术制备出厚度为0．3mm的Ni-Co-Cr基高温合金薄板，并用X射线衍射仪、光学显微镜、扫描电镜和拉伸设备研究了该合金热处理前后的显微组织及力学性能。结果表明，制备态合金为微晶结构，缺陷相对较多；热处理后晶粒迅速长大，缺陷密度大幅下降，并在晶粒内部形成了主要的沉淀强化相γ’相。与制备态合金相比，热处理后合金的力学性能得到明显改善，说明EB-PVD技术可以为制备性能优良的高温合金薄板提供一条新途径。
采用电子束物理气相沉积（EB-PVD）技术制备出厚度为0．3mm的Ni-Co-Cr基高温合金薄板，并用X射线衍射仪、光学显微镜、扫描电镜和拉伸设备研究了该合金热处理前后的显微组织及力学性能。结果表明，制备态合金为微晶结构，缺陷相对较多；热处理后晶粒迅速长大，缺陷密度大幅下降，并在晶粒内部形成了主要的沉淀强化相γ’相。与制备态合金相比，热处理后合金的力学性能得到明显改善，说明EB-PVD技术可以为制备性能优良的高温合金薄板提供一条新途径。
2006, 35(12):1975-1978.
Abstract:
通过XRD，SEM，EDX等手段研究了Sm-Fe合金的凝固和均匀化热处理过程中合金的相及微观结构的变化。结果表明：Sm-Fe合金在凝固中由于包晶反应不完全，母合金中不可避免地含有α-Fe，富Sm相等杂相：1050℃，24h的热处理能有效地消除合金中的杂相和残余应力，成功地制备出成分均一的单相2：17母合金。通过实验观测和分析，建立了Sm-Fe合金凝固过程中微观结构演变的物理模型。
通过XRD，SEM，EDX等手段研究了Sm-Fe合金的凝固和均匀化热处理过程中合金的相及微观结构的变化。结果表明：Sm-Fe合金在凝固中由于包晶反应不完全，母合金中不可避免地含有α-Fe，富Sm相等杂相：1050℃，24h的热处理能有效地消除合金中的杂相和残余应力，成功地制备出成分均一的单相2：17母合金。通过实验观测和分析，建立了Sm-Fe合金凝固过程中微观结构演变的物理模型。
2006, 35(12):1979-1982.
Abstract:
Effects of trace Er and Mn on the microstructures and mechanical properties of as-cast, homogenized, hot-rolled and cold-rolled alloys were investigated. Their existing forms and interactions with each other Were studied. The results showed that the element erbium and manganese had good effect on improving the Al-Mg alloy mechanical properties, but the strengthening effect would be weakened when they were added together, and influenced the function of individual element.
Effects of trace Er and Mn on the microstructures and mechanical properties of as-cast, homogenized, hot-rolled and cold-rolled alloys were investigated. Their existing forms and interactions with each other Were studied. The results showed that the element erbium and manganese had good effect on improving the Al-Mg alloy mechanical properties, but the strengthening effect would be weakened when they were added together, and influenced the function of individual element.
2006, 35(12):1983-1986.
Abstract:
In order to improve the electrochemical properties of Ti-based hydrogen storage alloys,the phase structures of Ti0.3Zr0.225V0.25Mn0.3-xNi0.45+x(x=0~0.25)hydrogen storage alloys were analyzed by XRD,SEM and EDS.The electrochemical properties of alloys were investigated.The results show that these alloys are composed of C14 Laves phase matrix with hexagonal structure and C15 Laves second phase with cubic structure.With the increase of x,the activation properties of alloys are decreased,while the cycle stabilities are improved.When x=0.05,the maximum discharge capacity of the alloy reaches to 426 mAh/g.These alloys show a great potential as negative electrode materials.
In order to improve the electrochemical properties of Ti-based hydrogen storage alloys,the phase structures of Ti0.3Zr0.225V0.25Mn0.3-xNi0.45+x(x=0~0.25)hydrogen storage alloys were analyzed by XRD,SEM and EDS.The electrochemical properties of alloys were investigated.The results show that these alloys are composed of C14 Laves phase matrix with hexagonal structure and C15 Laves second phase with cubic structure.With the increase of x,the activation properties of alloys are decreased,while the cycle stabilities are improved.When x=0.05,the maximum discharge capacity of the alloy reaches to 426 mAh/g.These alloys show a great potential as negative electrode materials.
2006, 35(12):1987-1990.
Abstract:
采用控制结晶工艺合成了球形Mn3O4，通过在球形Mn3O4的表面包覆Al（OH）3，然后与LiOH一起混合焙烧制备了表面掺杂Al的尖晶石LiMn2O4。采用SEM，XRD，EDS以及电池系统测试等方法，研究了所制备材料的结构和性能。SEM分析表明：表面掺杂后，Al（OH）3均匀地包覆在颗粒表面。XRD和EDS分析表明：焙烧后，Al元素占据了Mn的位置，且颗粒表面的Al含量高于其总体的平均含量，说明Al只是在表面富集，即表面掺杂。电池测试表明：表面掺杂后，尖晶石LiMn2O4的初始充放电容量有所下降，但在高温55℃下的循环性能有显著的提高，表面掺杂6％Al的尖晶石LiMn2O4 50次循环的容量保持率从68．3％提高到79．0％。说明以Al^3＋作为掺杂离子通过表面掺杂来改善LiMn2O4的高温循环性能是有效的。
采用控制结晶工艺合成了球形Mn3O4，通过在球形Mn3O4的表面包覆Al（OH）3，然后与LiOH一起混合焙烧制备了表面掺杂Al的尖晶石LiMn2O4。采用SEM，XRD，EDS以及电池系统测试等方法，研究了所制备材料的结构和性能。SEM分析表明：表面掺杂后，Al（OH）3均匀地包覆在颗粒表面。XRD和EDS分析表明：焙烧后，Al元素占据了Mn的位置，且颗粒表面的Al含量高于其总体的平均含量，说明Al只是在表面富集，即表面掺杂。电池测试表明：表面掺杂后，尖晶石LiMn2O4的初始充放电容量有所下降，但在高温55℃下的循环性能有显著的提高，表面掺杂6％Al的尖晶石LiMn2O4 50次循环的容量保持率从68．3％提高到79．0％。说明以Al^3＋作为掺杂离子通过表面掺杂来改善LiMn2O4的高温循环性能是有效的。
2006, 35(12):1991-1994.
Abstract:
The La1+xMg2-xNi9(x=0,0.5,1.0,1.5)alloys were prepared in high frequency induction furnace under Ar atmosphere.The compositions and phase structures of the prepared alloys were analyzed by XRD method,and their hydrogen storage capacities and electrochemical performances were investigated.The results show that with La content increasing,LaNi5 and(La,Mg)Ni3 phases are transferred to LaNi3 phase,Mg2Ni phase appears,the cell volume increases,and the hydrogen storage capacity and electrochemical performance are improved.While x=1.5,Mg2Ni phase disappears,the hydrogen storage properties of La2.5Mg0.5Ni9 alloy are impaired.The hydrogen storage capacity and electrochemical performance of La2MgNi9 alloy are better than those of the other three alloys.
The La1+xMg2-xNi9(x=0,0.5,1.0,1.5)alloys were prepared in high frequency induction furnace under Ar atmosphere.The compositions and phase structures of the prepared alloys were analyzed by XRD method,and their hydrogen storage capacities and electrochemical performances were investigated.The results show that with La content increasing,LaNi5 and(La,Mg)Ni3 phases are transferred to LaNi3 phase,Mg2Ni phase appears,the cell volume increases,and the hydrogen storage capacity and electrochemical performance are improved.While x=1.5,Mg2Ni phase disappears,the hydrogen storage properties of La2.5Mg0.5Ni9 alloy are impaired.The hydrogen storage capacity and electrochemical performance of La2MgNi9 alloy are better than those of the other three alloys.
2006, 35(12):1995-1998.
Abstract:
The PS304 powders were prepared by mechanical alloying(MA)using Ni,Cr,Cr2O3,Ag and BaF2/CaF2 powders.The influence of different milling time on powders characteristics was investigated.The results showed that the grain sizes were reduced during mechanical alloying,and the grain sizes of Cr2O3 and Ag were less than 50 nm after 15 h milling.Furthermore,with increase of milling time,the peaks of BaF2/CaF2 in XRD patterns weakened or disappeared,and no new phase was found.So BaF2/CaF2 maybe used to form supersaturated solid solution.EDX analysis showed that the final powder was composite powders.
The PS304 powders were prepared by mechanical alloying(MA)using Ni,Cr,Cr2O3,Ag and BaF2/CaF2 powders.The influence of different milling time on powders characteristics was investigated.The results showed that the grain sizes were reduced during mechanical alloying,and the grain sizes of Cr2O3 and Ag were less than 50 nm after 15 h milling.Furthermore,with increase of milling time,the peaks of BaF2/CaF2 in XRD patterns weakened or disappeared,and no new phase was found.So BaF2/CaF2 maybe used to form supersaturated solid solution.EDX analysis showed that the final powder was composite powders.
2006, 35(12):1999-2001.
Abstract:
以阳离子交换树脂为模板，以四氯化钛为原料采用溶胶．凝胶法制备了TiO2微球，并通过X射线衍射（XRD），红外光谱（FTIR），扫描电子显微镜（SEM）等手段对样品进行了表征。结果表明：制备的多层结构的TiO2微球直径在300μm-700μm之间，微球主要组分为锐钛矿晶型的TiO2，晶粒粒度约为16．3nm。分别以300W高压汞灯和太阳光为光源进行光催化实验，研究了样品对10mg／L甲基橙溶液光催化氧化的效果，结果表明此种TiO2微球具有很好的光催化性能。
以阳离子交换树脂为模板，以四氯化钛为原料采用溶胶．凝胶法制备了TiO2微球，并通过X射线衍射（XRD），红外光谱（FTIR），扫描电子显微镜（SEM）等手段对样品进行了表征。结果表明：制备的多层结构的TiO2微球直径在300μm-700μm之间，微球主要组分为锐钛矿晶型的TiO2，晶粒粒度约为16．3nm。分别以300W高压汞灯和太阳光为光源进行光催化实验，研究了样品对10mg／L甲基橙溶液光催化氧化的效果，结果表明此种TiO2微球具有很好的光催化性能。
2006, 35(12):2002-2004.
Abstract:
The influences of aging method on the shape memory effect and low temperature relaxation of the FeMnSiCrNi based alloy were studied. The results show that the separated carbide on the condition of aging after deforming has the features of smaller size, more amount and homogeneous distribution compared to that on the condition of undeformed aging, it is benefit to improve the matrix strength and to suppress the occurrence of nonreversible plastic deformation, thus the shape memory effect and recovery stress of the alloy are improved remarkably. The recovery strain and the recovery stress of the alloy with 10% deformation increase by 38% -139% and 12%-22%, respectively, compared to that with no deformation. The low temperature relaxations of different aging methods are not too obvious, it is about 16% at 213 K. Nevertheless, the improvement of recovery stress after deforming aging will increase the low temperature relaxation, but not remarkably, it is only about 0%-3.0% .
The influences of aging method on the shape memory effect and low temperature relaxation of the FeMnSiCrNi based alloy were studied. The results show that the separated carbide on the condition of aging after deforming has the features of smaller size, more amount and homogeneous distribution compared to that on the condition of undeformed aging, it is benefit to improve the matrix strength and to suppress the occurrence of nonreversible plastic deformation, thus the shape memory effect and recovery stress of the alloy are improved remarkably. The recovery strain and the recovery stress of the alloy with 10% deformation increase by 38% -139% and 12%-22%, respectively, compared to that with no deformation. The low temperature relaxations of different aging methods are not too obvious, it is about 16% at 213 K. Nevertheless, the improvement of recovery stress after deforming aging will increase the low temperature relaxation, but not remarkably, it is only about 0%-3.0% .
2006, 35(12):2005-2007.
Abstract:
用熔融快淬法制备了FeCuNbSiB非晶纤维，分别在300℃，400℃，450℃，500℃进行了1h退火处理。用扫描电镜分析了退火前后的纤维表面形貌。用X射线衍射分析了纤维在此温度段的晶化行为，估算其晶粒尺寸约为37nm。用差示扫描量热仪分析了纤维的晶化温度在530℃左右。若退火温度升高到约700℃时则有其它相析出，使软磁性能恶化。随退火温度的升高，纤维的比饱和磁化强度减小，纳米晶相体积分数增大，非晶相减少。对饱和磁化强度的影响占主导地位的是纳米晶相。
用熔融快淬法制备了FeCuNbSiB非晶纤维，分别在300℃，400℃，450℃，500℃进行了1h退火处理。用扫描电镜分析了退火前后的纤维表面形貌。用X射线衍射分析了纤维在此温度段的晶化行为，估算其晶粒尺寸约为37nm。用差示扫描量热仪分析了纤维的晶化温度在530℃左右。若退火温度升高到约700℃时则有其它相析出，使软磁性能恶化。随退火温度的升高，纤维的比饱和磁化强度减小，纳米晶相体积分数增大，非晶相减少。对饱和磁化强度的影响占主导地位的是纳米晶相。
2006, 35(12):2008-2010.
Abstract:
Au alloy/19Ni fiber composite was prepared by a special technology. The influence of heat treatment temperature and time on properties and structure of the composite was investigated. The results showed that the influence of heat treatment temperature on properties of Au alloy/19Ni fiber composite is larger than that of heat treatment time.
Au alloy/19Ni fiber composite was prepared by a special technology. The influence of heat treatment temperature and time on properties and structure of the composite was investigated. The results showed that the influence of heat treatment temperature on properties of Au alloy/19Ni fiber composite is larger than that of heat treatment time.
2006, 35(12):2011-2013.
Abstract:
采用X射线衍射（XRD），扫描电子显微镜（SEM）和差热分析仪（DTA）等研究了Al65Fe25Ni10元素混合粉末在机械合金化过程中的结构演变及热稳定性。结果表明：球磨5h后的粉末样品退火处理后生成Al5Fe2和Al3Ni2金属间化合物。球磨500h后得到纳米尺寸的Al（Fe，Ni）无序相。
采用X射线衍射（XRD），扫描电子显微镜（SEM）和差热分析仪（DTA）等研究了Al65Fe25Ni10元素混合粉末在机械合金化过程中的结构演变及热稳定性。结果表明：球磨5h后的粉末样品退火处理后生成Al5Fe2和Al3Ni2金属间化合物。球磨500h后得到纳米尺寸的Al（Fe，Ni）无序相。
2006, 35(12):2014-2016.
Abstract:
对一种实验镁锂新合金进行了室温轧制，轧出厚度为1．0mm的薄板，并对其进行了拉伸性能和残余应力测试。结果表明，随轧制变形量的增加，板材强度增加，塑性降低；经过适当退火处理后，板材延伸率可达到39％，强度保持在180MPa。冷轧板材残余应力值为-3．8MPa，对合金强度基本没有影响。
对一种实验镁锂新合金进行了室温轧制，轧出厚度为1．0mm的薄板，并对其进行了拉伸性能和残余应力测试。结果表明，随轧制变形量的增加，板材强度增加，塑性降低；经过适当退火处理后，板材延伸率可达到39％，强度保持在180MPa。冷轧板材残余应力值为-3．8MPa，对合金强度基本没有影响。
