Volume 0,Issue 3,2002 Table of Contents
2002(3):161-166.
Abstract:
It is pointed out that the images obtained by high-resolution electron microscopes is not always reflect the crystal structure directly, and the resolution of the structure image taken under a certain defocus condition is limited by the resolution of the electron microscope. The structure image with atomic resolution can be directly obtained only with the high-voltage high-resolution electron microscopes. The advantage of introducing diffraction analysis into high-resolution electron microscopy (HREM) is clarified,and an electron crystallographic image processing technique set up by combining the diffraction crystallography with HREM is introduced in the present paper. This technique makes realizable the ab initio crystal structure determination by HREM. It is shown that the resolution of the structure image obtained with a medium-voltage electron microscope can be enhanced up to the atomic resolution.Examples of applying this technique to the study of crystal structures and defects are given.
It is pointed out that the images obtained by high-resolution electron microscopes is not always reflect the crystal structure directly, and the resolution of the structure image taken under a certain defocus condition is limited by the resolution of the electron microscope. The structure image with atomic resolution can be directly obtained only with the high-voltage high-resolution electron microscopes. The advantage of introducing diffraction analysis into high-resolution electron microscopy (HREM) is clarified,and an electron crystallographic image processing technique set up by combining the diffraction crystallography with HREM is introduced in the present paper. This technique makes realizable the ab initio crystal structure determination by HREM. It is shown that the resolution of the structure image obtained with a medium-voltage electron microscope can be enhanced up to the atomic resolution.Examples of applying this technique to the study of crystal structures and defects are given.
2002(3):167-170.
Abstract:
研究了添加微量Sc，Zr的Al-Mg合金的再结晶行为，结果表明：Al-Mg-Sc-Zr合金的再结晶起始温度为400℃，细小、弥散基体共格的析出相对位错和亚昌的钉扎作用是合金再结晶温度大幅度提高的主要原因，再结晶形核机制为亚聚合机制。
研究了添加微量Sc，Zr的Al-Mg合金的再结晶行为，结果表明：Al-Mg-Sc-Zr合金的再结晶起始温度为400℃，细小、弥散基体共格的析出相对位错和亚昌的钉扎作用是合金再结晶温度大幅度提高的主要原因，再结晶形核机制为亚聚合机制。
2002(3):171-174.
Abstract:
The characteristics of the desorption process of the hydrogenation disproportionation product of NdFeB alloy were investigated. Nd Fe B alloy was melted in a vacuum mild frequency induction furnace. The sample was prepared by a hydrogenation disproportionation desorption recombination process. The mechanism of the recombination Nd 2Fe 14 B type hard magnetic material by a desorption of hydrogenation disproportionation product of NdFeB alloy was established by the comparison of the microstructures, X-ray diffraction patterns and magnetic properties.
The characteristics of the desorption process of the hydrogenation disproportionation product of NdFeB alloy were investigated. Nd Fe B alloy was melted in a vacuum mild frequency induction furnace. The sample was prepared by a hydrogenation disproportionation desorption recombination process. The mechanism of the recombination Nd 2Fe 14 B type hard magnetic material by a desorption of hydrogenation disproportionation product of NdFeB alloy was established by the comparison of the microstructures, X-ray diffraction patterns and magnetic properties.
2002(3):175-178.
Abstract:
研究了用能量为3．0keV－4．0keV，束流为80mA－200mA的低能氮和氩离子束对Ti膜进行轰击的作用以及用低能氮离子束对真空电弧沉积Ti－N膜层辅助沉积作用。结果表明：用低能氮离子束对Ti膜进行轰击可以形成Ti2N相，在（204）晶面出现一定的择优取向，并对Ti膜层有一定的强化作用；在低能氮离子束对真空电弧辅助沉积过程中，膜层表现为较高的显微硬度；随低能离子束能量的增大，真空电弧沉积膜层中Ti2N相增多，在（002）晶面出现择优取向，膜层晶粒有粗化的趋势，但显微硬度却增加，这与Hall-Petch公式不符。
研究了用能量为3．0keV－4．0keV，束流为80mA－200mA的低能氮和氩离子束对Ti膜进行轰击的作用以及用低能氮离子束对真空电弧沉积Ti－N膜层辅助沉积作用。结果表明：用低能氮离子束对Ti膜进行轰击可以形成Ti2N相，在（204）晶面出现一定的择优取向，并对Ti膜层有一定的强化作用；在低能氮离子束对真空电弧辅助沉积过程中，膜层表现为较高的显微硬度；随低能离子束能量的增大，真空电弧沉积膜层中Ti2N相增多，在（002）晶面出现择优取向，膜层晶粒有粗化的趋势，但显微硬度却增加，这与Hall-Petch公式不符。
2002(3):179-182.
Abstract:
A model of electrical conductivity of CuW composite and a model of CuW/CrCu solid material were established on the basis of physics in this paper,and the models were proved and corrected by experimental results subsequently.
A model of electrical conductivity of CuW composite and a model of CuW/CrCu solid material were established on the basis of physics in this paper,and the models were proved and corrected by experimental results subsequently.
6 Mechanical Properties of Coated Particulates Reinforced Heat Resistance Aluminium Matrix Composites
2002(3):183-186.
Abstract:
应用新型化学涂层工艺（置换法），成功地制备出结合紧密、光滑的Ni涂SiC粉末；分析对比了2种不同涂层工艺原理及涂层效果；分析了不同SiC增强Al-Fe-V-Si（0812）复合材料物理和力学性能，结果表明：由于涂覆SiC与基体的结合更加牢固，较软的基体合金与过渡层Ni的结合而降低了增强体与基体合金之间的孔隙率，从而使10％SiC（Ni）/Al-Fe-V-Si（0812）（质量分数，下同）复合材料在室温的断裂强度分别比基体和10％SiCp/Al-Fe-V-Si（0812）复合材料增加了62．15％和2．82％，在400℃时分别增加了55．3％，28．6％。
应用新型化学涂层工艺（置换法），成功地制备出结合紧密、光滑的Ni涂SiC粉末；分析对比了2种不同涂层工艺原理及涂层效果；分析了不同SiC增强Al-Fe-V-Si（0812）复合材料物理和力学性能，结果表明：由于涂覆SiC与基体的结合更加牢固，较软的基体合金与过渡层Ni的结合而降低了增强体与基体合金之间的孔隙率，从而使10％SiC（Ni）/Al-Fe-V-Si（0812）（质量分数，下同）复合材料在室温的断裂强度分别比基体和10％SiCp/Al-Fe-V-Si（0812）复合材料增加了62．15％和2．82％，在400℃时分别增加了55．3％，28．6％。
2002(3):187-191.
Abstract:
Base on the theory of electromagnetic field and magneto hydrodynamic, an apparatus of double-driving by magnetic force media with permanent magnet has been designed and manufactured. The characteristics analyzed from theory and experiment show that the apparatus can drive and stir molten metal without any directly contact; the shape and wave of meniscus can be controlled by the apparatus. When velocity of down driver is 35 turns per second, the upper is 20 turns per second, surface of metal liquid is more straight with little wave. That is like-stabilization state of meniscus; under this condition solidification structure of continuously casting is100% fine equiaxed structure, initial solidification point is descended and the solidification shell become thinner and uniformity.
Base on the theory of electromagnetic field and magneto hydrodynamic, an apparatus of double-driving by magnetic force media with permanent magnet has been designed and manufactured. The characteristics analyzed from theory and experiment show that the apparatus can drive and stir molten metal without any directly contact; the shape and wave of meniscus can be controlled by the apparatus. When velocity of down driver is 35 turns per second, the upper is 20 turns per second, surface of metal liquid is more straight with little wave. That is like-stabilization state of meniscus; under this condition solidification structure of continuously casting is100% fine equiaxed structure, initial solidification point is descended and the solidification shell become thinner and uniformity.
2002(3):192-196.
Abstract:
在研究Ti－Al二元相图及合金元素的影响、TiAl基合金显微组织类型与连续冷却转变、热处理实践及效果的基础上，提出了快速加热循环热处理新工艺，该工艺的特点是：加热速度快，单相构保温，保温时间短，冷却速度相对较慢。分析了该工艺的优点和缺点。
在研究Ti－Al二元相图及合金元素的影响、TiAl基合金显微组织类型与连续冷却转变、热处理实践及效果的基础上，提出了快速加热循环热处理新工艺，该工艺的特点是：加热速度快，单相构保温，保温时间短，冷却速度相对较慢。分析了该工艺的优点和缺点。
2002(3):197-200.
Abstract:
A computer automatic data acquisition and control system which can be used for data acquisition and reduction of temperature field during high rate directional solidification(HRS) process has been developed. The system has been applied to the investigation of DD98 single crystal superalloy solidification process. The result shows that the data are stable and the problem of interference at workshop is resolved, the solidification parameters, such as temperature gradient, width of mushy zone, are variable with the stationary heating temperature and withdrawal rate. The temperature gradient is highest in the starting stage and becomes stable during the late stage of solidification. The width of mush zone is increased in the solidification process.
A computer automatic data acquisition and control system which can be used for data acquisition and reduction of temperature field during high rate directional solidification(HRS) process has been developed. The system has been applied to the investigation of DD98 single crystal superalloy solidification process. The result shows that the data are stable and the problem of interference at workshop is resolved, the solidification parameters, such as temperature gradient, width of mushy zone, are variable with the stationary heating temperature and withdrawal rate. The temperature gradient is highest in the starting stage and becomes stable during the late stage of solidification. The width of mush zone is increased in the solidification process.
2002(3):201-204.
Abstract:
SCS-6 SiC/Ti matrix composite was prepared by a method of matrix coated fiber with magnetron sputtering and hot isostatic pressing. The tensile strength of the composite in as-processed condition was measured and the effects on the property were discussed. It is shown that the chemical concentration of the alloying elements in the coating is nearly the same as that in the target material. It was pointed out that the uniformity of the fiber distribution in the composite, the content of oxygen in the coating and the diffusion and reaction of elements at the fiber/matrix interface are the main factors for the property degradation of the composite.
SCS-6 SiC/Ti matrix composite was prepared by a method of matrix coated fiber with magnetron sputtering and hot isostatic pressing. The tensile strength of the composite in as-processed condition was measured and the effects on the property were discussed. It is shown that the chemical concentration of the alloying elements in the coating is nearly the same as that in the target material. It was pointed out that the uniformity of the fiber distribution in the composite, the content of oxygen in the coating and the diffusion and reaction of elements at the fiber/matrix interface are the main factors for the property degradation of the composite.
2002(3):205-208.
Abstract:
Titanium nitride films were deposited by ion beam assisted deposition, magnetron sputtering and ion-beam assisted magnetron sputtering deposition on GCr15 and Si substrate. The structure and mechanical properties such as micro-hardness, bonding strength, wear resistance were studied as well as the corrosion resistance. The results show that the hardness, bonding strength and wear resistance of the titanium nitride films deposited by ion-beam assisted magnetron sputtering are increased greatly and the corrosion resistance of films is also improved.
Titanium nitride films were deposited by ion beam assisted deposition, magnetron sputtering and ion-beam assisted magnetron sputtering deposition on GCr15 and Si substrate. The structure and mechanical properties such as micro-hardness, bonding strength, wear resistance were studied as well as the corrosion resistance. The results show that the hardness, bonding strength and wear resistance of the titanium nitride films deposited by ion-beam assisted magnetron sputtering are increased greatly and the corrosion resistance of films is also improved.
2002(3):209-212.
Abstract:
By studying the bright discharge phenomenon in the sputtering process and the deposition rate of the AlN films, it was found that an instable AlN layer was formed on the target surface with increasing the N 2 concentration. Since the sputtering rate of AlN target was very lower than that of the Al target, the deposition rate of AlN films was decreased rapidly. At the meantime, the effects of other experimental parameters on the deposition rate have been studied. The results shown that the deposition rate decreased with increasing the distance ( D ) from target to substrate and decreasing target power, whereas the deposition rate reached a extremum with increasing sputtering pressure from 03 Pa to 12 Pa.
By studying the bright discharge phenomenon in the sputtering process and the deposition rate of the AlN films, it was found that an instable AlN layer was formed on the target surface with increasing the N 2 concentration. Since the sputtering rate of AlN target was very lower than that of the Al target, the deposition rate of AlN films was decreased rapidly. At the meantime, the effects of other experimental parameters on the deposition rate have been studied. The results shown that the deposition rate decreased with increasing the distance ( D ) from target to substrate and decreasing target power, whereas the deposition rate reached a extremum with increasing sputtering pressure from 03 Pa to 12 Pa.
Wang Yizhong~
,
Zhang Maocai~
,
Jao Yi~
,
Han Baoshan~
,
Zhang Zhenrong~
,
Liang Bingqing~
,
Wang Yinjun~
,
Shen Baogen~
2002(3):213-216.
Abstract:
采用直流溅射多层结合退火技术，制备了不同富铁量的各向同性Fe－Pt纳米晶永磁薄膜。对这些永磁薄膜的研究表明：在500℃退火3min－10min得到的所有不同富Fe量的Fe－Pt永磁薄膜是各向同性的；它们的磁滞回线都显现单相的硬磁行为；所有的薄膜显示出剩磁增强效应，其剩磁随富Fe含量的增加而增大。磁力显微镜观测表明，在热退磁状态下Fe－Pt薄膜显现出不规则的模跨数个晶凿的岛状畴，其大小是平均晶粒尺寸的7倍－10倍。
采用直流溅射多层结合退火技术，制备了不同富铁量的各向同性Fe－Pt纳米晶永磁薄膜。对这些永磁薄膜的研究表明：在500℃退火3min－10min得到的所有不同富Fe量的Fe－Pt永磁薄膜是各向同性的；它们的磁滞回线都显现单相的硬磁行为；所有的薄膜显示出剩磁增强效应，其剩磁随富Fe含量的增加而增大。磁力显微镜观测表明，在热退磁状态下Fe－Pt薄膜显现出不规则的模跨数个晶凿的岛状畴，其大小是平均晶粒尺寸的7倍－10倍。
2002(3):217-220.
Abstract:
In this paper, the microstructure and the electrochemical properties of RE(NiCoMnAl) 5 hydride alloy with different composition of rare earth have been investigated. The results show that, for all the samples studied, the crystalline structure is CaCu 5 type hexagonal structure and the metallographic structure is dendrite, while, the unit-cell volume decreases after being substituted part La by other rare earth elements. The effect of the composition of rare earth on the electrochemical properties of RE(NiCoMnAl) 5 alloy is marked. As compared with La(NiCoMnAl) 5 alloy, the electrochemical capacity of RE(NiCoMnAl) 5 alloy decreases, the high-rate dischargeability improves and the cycling life enhances, where La is part substituted by others rare earth including Ce, Pr, Nd. The effect of the composition of rare earth on the electrochemical properties is related to the change of the microstructure of RE(NiCoMnAl) 5 alloy.
In this paper, the microstructure and the electrochemical properties of RE(NiCoMnAl) 5 hydride alloy with different composition of rare earth have been investigated. The results show that, for all the samples studied, the crystalline structure is CaCu 5 type hexagonal structure and the metallographic structure is dendrite, while, the unit-cell volume decreases after being substituted part La by other rare earth elements. The effect of the composition of rare earth on the electrochemical properties of RE(NiCoMnAl) 5 alloy is marked. As compared with La(NiCoMnAl) 5 alloy, the electrochemical capacity of RE(NiCoMnAl) 5 alloy decreases, the high-rate dischargeability improves and the cycling life enhances, where La is part substituted by others rare earth including Ce, Pr, Nd. The effect of the composition of rare earth on the electrochemical properties is related to the change of the microstructure of RE(NiCoMnAl) 5 alloy.
2002(3):221-224.
Abstract:
以Ce为主研究了元素对起燃温度的影响并与国外研究较多的钙元素的作用进行了对比，认为Ce与Ca同样对镁合金的阻燃具有显著作用，添加1％的Ce，起燃温度提高约180℃，而添加1％的Ca，起燃温度提高约280℃。可直接暴露在大气中熔炼镁合金。研究表明：添加稀土Ce的镁合金的表面膜基休币原来的MgO疏松结构转变为由MgO，Ce2O3，Al2O3及Mg17Al2组成的复合致密结构，具有很好的阻燃效果。
以Ce为主研究了元素对起燃温度的影响并与国外研究较多的钙元素的作用进行了对比，认为Ce与Ca同样对镁合金的阻燃具有显著作用，添加1％的Ce，起燃温度提高约180℃，而添加1％的Ca，起燃温度提高约280℃。可直接暴露在大气中熔炼镁合金。研究表明：添加稀土Ce的镁合金的表面膜基休币原来的MgO疏松结构转变为由MgO，Ce2O3，Al2O3及Mg17Al2组成的复合致密结构，具有很好的阻燃效果。
2002(3):225-228.
Abstract:
A kind of binder technology for extrusion molding of hardmetal powder has been developed. By optimizing the binder formulation design and its fabrication method and technical conditions, the novel binders, with excellent properties and uniform distribution, were manufactured. The thermal debinding processes and its mechanism of binder and feedstock have been studied. It is found that the thermal debinding can be divided into two stages, egthe low temperature stage and the high temperature stage. And their thermal debinding mechanism is the mechanism of thermal diffusion, but the thermal debinding activation energies are different in the two stages. The results show that adding of other components acted as a catalyzeing in either binder or feedstock, and can decrease effectively the activation energy of thermal debinding processes.
A kind of binder technology for extrusion molding of hardmetal powder has been developed. By optimizing the binder formulation design and its fabrication method and technical conditions, the novel binders, with excellent properties and uniform distribution, were manufactured. The thermal debinding processes and its mechanism of binder and feedstock have been studied. It is found that the thermal debinding can be divided into two stages, egthe low temperature stage and the high temperature stage. And their thermal debinding mechanism is the mechanism of thermal diffusion, but the thermal debinding activation energies are different in the two stages. The results show that adding of other components acted as a catalyzeing in either binder or feedstock, and can decrease effectively the activation energy of thermal debinding processes.
2002(3):229-231.
Abstract:
CeO 2 nanoparticles hydrosol was synthesized by colloidal chemical method. The optimum experiment conditions for the preparation of CeO 2 nanoparticles hydrosol were discussed. The effects of pH values, the reactant concentration and temperature on peptization process were studied. TEM photos showed that the CeO 2 nanoparticles were spherical in shape and the size was about 3nm. Particle size distribution was in narrow range, and no agglomerates were observed. ED images indicated that the CeO 2 nanoparticles were polycrystalline structure, and some of CeO 2 were monocrystal particles.
CeO 2 nanoparticles hydrosol was synthesized by colloidal chemical method. The optimum experiment conditions for the preparation of CeO 2 nanoparticles hydrosol were discussed. The effects of pH values, the reactant concentration and temperature on peptization process were studied. TEM photos showed that the CeO 2 nanoparticles were spherical in shape and the size was about 3nm. Particle size distribution was in narrow range, and no agglomerates were observed. ED images indicated that the CeO 2 nanoparticles were polycrystalline structure, and some of CeO 2 were monocrystal particles.
2002(3):232-235.
Abstract:
采用正交实验设计的方法 ,系统的研究了注射压力、注射温度、注射速度、模具温度及其交互作用对注射成形生坯质量的影响 ,通过直观分析和方差分析 ,评价了各参数影响生坯质量的显著程度 ,优化了注射成形参数。结果表明 :注射温度、注射压力及注射温度与模具温度的交互作用对生坯强度影响显著 ,注射温度和注射压力对生坯密度影响显著 ;注射压力增加 ,生坯密度和抗弯强度都增高 ;注射温度增高 ,生坯密度降低 ,注射温度在 165℃～ 170℃之间时 ,成形坯抗弯强度变化不大 ,175℃时明显下降 ;模具温度和注射速度分别为 3 0℃和 60 %时 ,生坯密度、抗弯强度达到最高值 ;尺寸为 6mm× 6mm× 42mm矩形生坯的最佳注射参数为 :注射压力 14 4MPa ;注射温度165℃ ;注射速度 60 % ;模具温度 3 0℃。
采用正交实验设计的方法 ,系统的研究了注射压力、注射温度、注射速度、模具温度及其交互作用对注射成形生坯质量的影响 ,通过直观分析和方差分析 ,评价了各参数影响生坯质量的显著程度 ,优化了注射成形参数。结果表明 :注射温度、注射压力及注射温度与模具温度的交互作用对生坯强度影响显著 ,注射温度和注射压力对生坯密度影响显著 ;注射压力增加 ,生坯密度和抗弯强度都增高 ;注射温度增高 ,生坯密度降低 ,注射温度在 165℃～ 170℃之间时 ,成形坯抗弯强度变化不大 ,175℃时明显下降 ;模具温度和注射速度分别为 3 0℃和 60 %时 ,生坯密度、抗弯强度达到最高值 ;尺寸为 6mm× 6mm× 42mm矩形生坯的最佳注射参数为 :注射压力 14 4MPa ;注射温度165℃ ;注射速度 60 % ;模具温度 3 0℃。
2002(3):236-239.
Abstract:
The paper introduced the use of the simplex optimization method to search the best for parameters for measurement of Fe, Cu, K, Mg, Zn, Mn, As, Pb, Sb and Bi in biololgical samples by using a atomic absorption spectrophotometer. The method has the advantages of quickness and accuracy. The results were satisfied.
The paper introduced the use of the simplex optimization method to search the best for parameters for measurement of Fe, Cu, K, Mg, Zn, Mn, As, Pb, Sb and Bi in biololgical samples by using a atomic absorption spectrophotometer. The method has the advantages of quickness and accuracy. The results were satisfied.
