Volume 33,Issue 11,2004 Table of Contents
2004, 33(11):1121-1126.
Abstract:
Recent developments in Ceramic Injection Molding (CIM) techniques are reviewed. The influence of the ceramic powder and the formulation of the organic binder (especially the surfactant) on the ceramic feedstock, and the green and sintered parts are discussed in detail. Also, the influence of the mixing sequence, the injection parameters, the debinding methods, and the corresponding debinding rate on the fluidity of feedstock, and the properties of the green and sintered parts are described here.
Recent developments in Ceramic Injection Molding (CIM) techniques are reviewed. The influence of the ceramic powder and the formulation of the organic binder (especially the surfactant) on the ceramic feedstock, and the green and sintered parts are discussed in detail. Also, the influence of the mixing sequence, the injection parameters, the debinding methods, and the corresponding debinding rate on the fluidity of feedstock, and the properties of the green and sintered parts are described here.
2004, 33(11):1127-1131.
Abstract:
以水／环己烷／曲拉通-100／正己醇四元油包水微乳体系中的微乳液滴为纳米微反应器，通过分别增溶在微反应器中的氧氯化锆和沉淀剂(氨水)发生反应，可以制备出粒径分布均匀、球形度较好的纳米级超细氧化锆粉体。实验中采用粒度分析仪，XRD，SEM，TEM，比表面仪等对获得的粉体进行了表征，利用高温综合热分析仪分析了粉体的致密化行为，发现在烧结致密化过程中，无定型态的粉体于475℃左右结晶成为四方相的氧化锆，在1080℃～1280℃范围内完成致密化收缩。干压成型的坯体在1400℃，2h下烧结相对密度达98％以上，烧结体晶相为100％的四方相。
以水／环己烷／曲拉通-100／正己醇四元油包水微乳体系中的微乳液滴为纳米微反应器，通过分别增溶在微反应器中的氧氯化锆和沉淀剂(氨水)发生反应，可以制备出粒径分布均匀、球形度较好的纳米级超细氧化锆粉体。实验中采用粒度分析仪，XRD，SEM，TEM，比表面仪等对获得的粉体进行了表征，利用高温综合热分析仪分析了粉体的致密化行为，发现在烧结致密化过程中，无定型态的粉体于475℃左右结晶成为四方相的氧化锆，在1080℃～1280℃范围内完成致密化收缩。干压成型的坯体在1400℃，2h下烧结相对密度达98％以上，烧结体晶相为100％的四方相。
3 Relationship between Supercooled Liquid Region and Bond Parameters of Pd-Based Bulk Metallic Glasses
2004, 33(11):1132-1135.
Abstract:
通过计算机对Pd基大块金属玻璃的过冷液相区宽度△Tx的表达式进行回归处理分析，得到Pd基大块金属玻璃过冷液相区△Tx与反映合金混合热变化的3个键参数(电负性差△X、原子尺寸差的百分数δ和电子浓度n)之间存在如下关系：△Tx=29．36909 3602．45898(△x)^2 9992．76758δ^2-3．95897n^2/3，相关系数为97．2％。△Tx随多元合金的电负性差和原子尺寸差的百分数的增加而增加，而随电子浓度的增加而略有降低。
通过计算机对Pd基大块金属玻璃的过冷液相区宽度△Tx的表达式进行回归处理分析，得到Pd基大块金属玻璃过冷液相区△Tx与反映合金混合热变化的3个键参数(电负性差△X、原子尺寸差的百分数δ和电子浓度n)之间存在如下关系：△Tx=29．36909 3602．45898(△x)^2 9992．76758δ^2-3．95897n^2/3，相关系数为97．2％。△Tx随多元合金的电负性差和原子尺寸差的百分数的增加而增加，而随电子浓度的增加而略有降低。
2004, 33(11):1136-1139.
Abstract:
用磁控溅射法将NiTi薄膜沉积在纯Cu箔片上，在800℃分别固溶30min，45min，60min和120min：采用X射线傅氏线形分析法计算各固溶时间的位错密度及位错分布参量。随固溶时间的增加，平均位错密度不断下降；亚晶粒尺寸D逐渐增加；平均位错分布参量基本不变。由位错密度及位错分布参量计算得到NiTi薄膜材料的显微硬度值，随固溶时间的增加，显微硬度计算值明显低于测量值。
用磁控溅射法将NiTi薄膜沉积在纯Cu箔片上，在800℃分别固溶30min，45min，60min和120min：采用X射线傅氏线形分析法计算各固溶时间的位错密度及位错分布参量。随固溶时间的增加，平均位错密度不断下降；亚晶粒尺寸D逐渐增加；平均位错分布参量基本不变。由位错密度及位错分布参量计算得到NiTi薄膜材料的显微硬度值，随固溶时间的增加，显微硬度计算值明显低于测量值。
2004, 33(11):1140-1142.
Abstract:
根据1种新的Sol—Gel工艺设计思路，提出了在SiO2-CaO-MgO-P2O5多元体系中制备均匀凝胶的方法，并采用RAMAN，XRD和SEM对制得的凝胶物性进行了分析。结果表明：利用该方法可以成功地制备出均匀的生物凝胶。生物凝胶分子网络呈群聚态，包括架状、层状、链环状、二聚体及单体，以架状为主。随热处理温度升高，生物凝胶的晶化程度增加。生物凝胶干燥试样中有大量微裂纹和孔洞，并含有残余OH基团。试样的这些特性可增加其在溶液中与水和小分子蛋白质键合的能力。
根据1种新的Sol—Gel工艺设计思路，提出了在SiO2-CaO-MgO-P2O5多元体系中制备均匀凝胶的方法，并采用RAMAN，XRD和SEM对制得的凝胶物性进行了分析。结果表明：利用该方法可以成功地制备出均匀的生物凝胶。生物凝胶分子网络呈群聚态，包括架状、层状、链环状、二聚体及单体，以架状为主。随热处理温度升高，生物凝胶的晶化程度增加。生物凝胶干燥试样中有大量微裂纹和孔洞，并含有残余OH基团。试样的这些特性可增加其在溶液中与水和小分子蛋白质键合的能力。
2004, 33(11):1143-1148.
Abstract:
通过对混合元素法Ti-Fe合金烧结过程中的膨胀／收缩行为、淬火态和烧结态显微组织的分析，研究了添加铁对混合元素法Ti—Fe合金的烧结行为和组织演化的影响。结果表明：铁元素对钛粉末的烧结行为的影响可分为2个阶段：(1)铁元素的扩散均匀化；(2)单相的β-Ti(Fe)的烧结致密化。在升温速率为5K／min和铁含量为5w／％的情况下，铁元素在Ti-Fe系的第1共晶点(1085℃)之前就完全固溶到钛基体中，瞬时液相并没有出现。添加铁元素促进了Ti—Fe合金的烧结致密化。随着铁含量的提高，原始β晶粒平均尺寸及片状α晶团(Colony)的平均尺寸略有增加，α片的平均厚度急剧下降。铁的高扩散速率和铁的β相稳定效果是导致这些结果的主要原因。
通过对混合元素法Ti-Fe合金烧结过程中的膨胀／收缩行为、淬火态和烧结态显微组织的分析，研究了添加铁对混合元素法Ti—Fe合金的烧结行为和组织演化的影响。结果表明：铁元素对钛粉末的烧结行为的影响可分为2个阶段：(1)铁元素的扩散均匀化；(2)单相的β-Ti(Fe)的烧结致密化。在升温速率为5K／min和铁含量为5w／％的情况下，铁元素在Ti-Fe系的第1共晶点(1085℃)之前就完全固溶到钛基体中，瞬时液相并没有出现。添加铁元素促进了Ti—Fe合金的烧结致密化。随着铁含量的提高，原始β晶粒平均尺寸及片状α晶团(Colony)的平均尺寸略有增加，α片的平均厚度急剧下降。铁的高扩散速率和铁的β相稳定效果是导致这些结果的主要原因。
2004, 33(11):1149-1152.
Abstract:
The electromagnetic force of electromagnetic casting induced in cylindrical molten metal was analyzed by mathematical method and experiment research. It can be concluded that where is the electromagnetic force impose on and what is the direction of the force, and the electromagnetic force was concerned not only with the magnetic flux density but also with the grads of the magnetic flux density. Furthermore, it can be summarized that the nonconservative component of the force was brought by the asymmetry of the distribution of the electromagnetic field. Some experiments are taken to research the influence of the parameters (inductor current, inductor shape etc.) on the distribution of the electromagnetic fields.
The electromagnetic force of electromagnetic casting induced in cylindrical molten metal was analyzed by mathematical method and experiment research. It can be concluded that where is the electromagnetic force impose on and what is the direction of the force, and the electromagnetic force was concerned not only with the magnetic flux density but also with the grads of the magnetic flux density. Furthermore, it can be summarized that the nonconservative component of the force was brought by the asymmetry of the distribution of the electromagnetic field. Some experiments are taken to research the influence of the parameters (inductor current, inductor shape etc.) on the distribution of the electromagnetic fields.
2004, 33(11):1157-1160.
Abstract:
在 SPF-430H 溅射系统上采用不加偏压的射频磁控溅射法制备了 TbCo 非晶垂直磁化膜, 并就 Cr 底层对 TbCo 非晶垂直磁化膜磁性能的影响进行了研究。结果表明,Cr 底层的存在能够增强 TbCo 非晶垂直磁化膜的磁各向异性,并使得其矫顽力增加。分别采用 VTBH-1 型高感度振动样品磁强计和 MTL-1 磁转矩系统测量了 TbCo薄膜的磁滞回线和磁转矩曲线。结果发现,厚度为 120 nm,并带有 180 nm 厚度 Cr 底层的 Tb31C69 薄膜的矫顽力和磁各向异性能分别高达 51.2×104 A/m 和 0.457 J/cm3;没有带 Cr 底层的同样厚度的 Tb31C69 薄膜的矫顽力和磁各向异性能分别只有 35.2×104 A/m 和 0.324 J/cm3。Hitachi X-650 型扫描电镜的观测结果表明,带有 Cr 底层的TbCo 薄膜具有柱状结构,这一柱状结构导致了磁各向异性能的增强以及矫顽力的提高。
在 SPF-430H 溅射系统上采用不加偏压的射频磁控溅射法制备了 TbCo 非晶垂直磁化膜, 并就 Cr 底层对 TbCo 非晶垂直磁化膜磁性能的影响进行了研究。结果表明,Cr 底层的存在能够增强 TbCo 非晶垂直磁化膜的磁各向异性,并使得其矫顽力增加。分别采用 VTBH-1 型高感度振动样品磁强计和 MTL-1 磁转矩系统测量了 TbCo薄膜的磁滞回线和磁转矩曲线。结果发现,厚度为 120 nm,并带有 180 nm 厚度 Cr 底层的 Tb31C69 薄膜的矫顽力和磁各向异性能分别高达 51.2×104 A/m 和 0.457 J/cm3;没有带 Cr 底层的同样厚度的 Tb31C69 薄膜的矫顽力和磁各向异性能分别只有 35.2×104 A/m 和 0.324 J/cm3。Hitachi X-650 型扫描电镜的观测结果表明,带有 Cr 底层的TbCo 薄膜具有柱状结构,这一柱状结构导致了磁各向异性能的增强以及矫顽力的提高。
2004, 33(11):1161-1164.
Abstract:
The crystal loops of Gallium nitride (GaN) were deposited on silicon (111) substrate by using hot-wall chemical vapor deposition and thermal treatment. Scanning electron microscopy (SEM), selected area electron diffraction (SAED), x-ray diffraction (XRD), photoluminescence (PL) and Fourier Transform Infrared transmission (FTIR) Spectroscopy were employed to analyze the surface morphology, structure and optical properties of GaN layer. SEM image shows five half-loops attached to a crystal string side by side in the uniform films. XRD, SAED patterns reveal that the formed loops are polycrystalline hexagonal gallium nitride. FTIR pattern shows the main composition of the film is GaN and it contains trifle carbon contamination. New feature is found in PL pattern of the crystal loops, which is different from the bulk GaN films.
The crystal loops of Gallium nitride (GaN) were deposited on silicon (111) substrate by using hot-wall chemical vapor deposition and thermal treatment. Scanning electron microscopy (SEM), selected area electron diffraction (SAED), x-ray diffraction (XRD), photoluminescence (PL) and Fourier Transform Infrared transmission (FTIR) Spectroscopy were employed to analyze the surface morphology, structure and optical properties of GaN layer. SEM image shows five half-loops attached to a crystal string side by side in the uniform films. XRD, SAED patterns reveal that the formed loops are polycrystalline hexagonal gallium nitride. FTIR pattern shows the main composition of the film is GaN and it contains trifle carbon contamination. New feature is found in PL pattern of the crystal loops, which is different from the bulk GaN films.
2004, 33(11):1165-1169.
Abstract:
利用溶胶-凝胶自燃烧高温合成法制备了稀土La掺杂钡铁氧体BaLa0.3Fe11.7O19纳米粉末.用X射线衍射仪、振动样品磁强计和透射电镜对不同溶胶组成下合成的粉末的结构、磁学性能、粒度及形貌进行了研究.试验表明用氨水调节溶液起始pH值以及加入适量的柠檬酸和乙二醇是合成结构纯净、性能优异的BaLa0.3Fe11.7O19纳米粉末的2个关键步骤.在溶液起始pH值呈弱酸性(7.0左右)、柠檬酸/硝酸盐=3、煅烧温度为850℃,保温1 h的条件下,利用溶胶-凝胶自燃烧高温合成法可以制备出粒径为36nm的磁铅石结构的BaLa0.3Fe11.7O19粉末,其磁学性能优异,比饱和磁化强度可达65.54 A·m2/kg,矫顽力可达433 kA/m.
利用溶胶-凝胶自燃烧高温合成法制备了稀土La掺杂钡铁氧体BaLa0.3Fe11.7O19纳米粉末.用X射线衍射仪、振动样品磁强计和透射电镜对不同溶胶组成下合成的粉末的结构、磁学性能、粒度及形貌进行了研究.试验表明用氨水调节溶液起始pH值以及加入适量的柠檬酸和乙二醇是合成结构纯净、性能优异的BaLa0.3Fe11.7O19纳米粉末的2个关键步骤.在溶液起始pH值呈弱酸性(7.0左右)、柠檬酸/硝酸盐=3、煅烧温度为850℃,保温1 h的条件下,利用溶胶-凝胶自燃烧高温合成法可以制备出粒径为36nm的磁铅石结构的BaLa0.3Fe11.7O19粉末,其磁学性能优异,比饱和磁化强度可达65.54 A·m2/kg,矫顽力可达433 kA/m.
2004, 33(11):1170-1173.
Abstract:
通过X射线衍射(XRD)、金相显微镜、扫描电镜(SEM)、能谱分析(EDS)及压痕技术研究了Er对Mo5Si3基合金(钼硅质量比5：1)室温组织与性能的影响。研究结果表明：Er的添加导致了三元化合物相Mo3Er2Si4的形成：合金的组织形貌随Er含量不同有所差异，且随Er含量增加，组织中MoSi2相逐渐减少，三元化合物的含量则逐渐增加：过渡族元素Er在MoSi2中不固溶，在Mo5Si3中的溶解度也极小：Er含量为1wt％时得到略高的室温硬度值。Er难以明显改善室温断裂韧性。
通过X射线衍射(XRD)、金相显微镜、扫描电镜(SEM)、能谱分析(EDS)及压痕技术研究了Er对Mo5Si3基合金(钼硅质量比5：1)室温组织与性能的影响。研究结果表明：Er的添加导致了三元化合物相Mo3Er2Si4的形成：合金的组织形貌随Er含量不同有所差异，且随Er含量增加，组织中MoSi2相逐渐减少，三元化合物的含量则逐渐增加：过渡族元素Er在MoSi2中不固溶，在Mo5Si3中的溶解度也极小：Er含量为1wt％时得到略高的室温硬度值。Er难以明显改善室温断裂韧性。
2004, 33(11):1174-1177.
Abstract:
采用双层辉光离子渗碳技术在本底真空度为 5×10-3Pa 的高真空下,用 99.999%的高纯氩气进行无氢渗碳。在整个工艺过程中,没有涉及到氢元素,实现了无氢渗碳。试样材质为 TA1 工业纯钛,用透射电镜(TEM)观察渗层结构;X 射线衍射(XRD)测定渗层的相组成;用 M200 耐磨试验机测定渗碳试样的耐磨性能;渗碳试样的磨痕表面状态用 TR240型粗糙度仪测定。渗碳层厚度大于 100 μm。表面层生成的是 TiC,基体仍为 α-Ti。近表面渗层维氏硬度为 6 000 MPa,表面的硬度远大于此值。摩擦系数 0.11。纯钛经过无氢渗碳后,与未经过处理的纯钛相比磨损量仅为纯钛试样的1/1 592.5。研究得出:钛材经过双辉等离子无氢渗碳后,不仅提高了表面的硬度,同时降低了摩擦系数,因而使耐磨性能得到了大幅度的提高。
采用双层辉光离子渗碳技术在本底真空度为 5×10-3Pa 的高真空下,用 99.999%的高纯氩气进行无氢渗碳。在整个工艺过程中,没有涉及到氢元素,实现了无氢渗碳。试样材质为 TA1 工业纯钛,用透射电镜(TEM)观察渗层结构;X 射线衍射(XRD)测定渗层的相组成;用 M200 耐磨试验机测定渗碳试样的耐磨性能;渗碳试样的磨痕表面状态用 TR240型粗糙度仪测定。渗碳层厚度大于 100 μm。表面层生成的是 TiC,基体仍为 α-Ti。近表面渗层维氏硬度为 6 000 MPa,表面的硬度远大于此值。摩擦系数 0.11。纯钛经过无氢渗碳后,与未经过处理的纯钛相比磨损量仅为纯钛试样的1/1 592.5。研究得出:钛材经过双辉等离子无氢渗碳后,不仅提高了表面的硬度,同时降低了摩擦系数,因而使耐磨性能得到了大幅度的提高。
2004, 33(11):1178-1181.
Abstract:
通过力学性能、电学性能测量和金相、电镜观察对Cu-Al2O3弥散强化铜合金的冷加工及退火后性能和组织的变化进行了系统研究。结果表明：挤压态合金随冷拉拔变形量增大，σb和σ0.2逐渐升高，δ逐渐下降，电导率则变化甚微。合金经92％的变形后，σb，σ0.2,δ和电导率分别为490MPa，485MPa，10％和91．4％IACS，其在400℃～1000℃温度范围退火后性能有不同程度的回复。不同变形量的合金样品900℃ 1h退火后性能均回复至挤压态水平，且未见再结晶现象。冷拉拔有利于粉末颗粒间进一步冶金化结合。
通过力学性能、电学性能测量和金相、电镜观察对Cu-Al2O3弥散强化铜合金的冷加工及退火后性能和组织的变化进行了系统研究。结果表明：挤压态合金随冷拉拔变形量增大，σb和σ0.2逐渐升高，δ逐渐下降，电导率则变化甚微。合金经92％的变形后，σb，σ0.2,δ和电导率分别为490MPa，485MPa，10％和91．4％IACS，其在400℃～1000℃温度范围退火后性能有不同程度的回复。不同变形量的合金样品900℃ 1h退火后性能均回复至挤压态水平，且未见再结晶现象。冷拉拔有利于粉末颗粒间进一步冶金化结合。
2004, 33(11):1182-1185.
Abstract:
采用 PHI-650 型扫描俄歇电子能谱(SAM)研究金属铀在超高真空原位断裂后断面在不同氧气暴露量和温度下的氧化规律和杂质元素在表面的扩散行为。实验中采用在主真空室内的装置在超高真空中打断铀样品,然后在 1×10-5 Pa的压力下充入暴露量为 5 L、20 L、70 L、170 L 和 270 L 的高纯氧气进行氧化实验并获取 U,O,S 和 C 的俄歇电子谱。实验结果表明:在 5 L 和 20 L 的氧气暴露量下表面形成 UO2 和金属 U 的混合物,在大于 70 L 情况下只形成 UO2。 在1×10-7 Pa 的真空中将 UO2 加热到 100℃,150℃,200℃和 300℃并进行 SAM 分析,结果显示:随温度的升高,尤其是在 300℃时元素 S 向表面扩散,形成明显的富集,且表面氧和铀的原子浓度比明显下降。
采用 PHI-650 型扫描俄歇电子能谱(SAM)研究金属铀在超高真空原位断裂后断面在不同氧气暴露量和温度下的氧化规律和杂质元素在表面的扩散行为。实验中采用在主真空室内的装置在超高真空中打断铀样品,然后在 1×10-5 Pa的压力下充入暴露量为 5 L、20 L、70 L、170 L 和 270 L 的高纯氧气进行氧化实验并获取 U,O,S 和 C 的俄歇电子谱。实验结果表明:在 5 L 和 20 L 的氧气暴露量下表面形成 UO2 和金属 U 的混合物,在大于 70 L 情况下只形成 UO2。 在1×10-7 Pa 的真空中将 UO2 加热到 100℃,150℃,200℃和 300℃并进行 SAM 分析,结果显示:随温度的升高,尤其是在 300℃时元素 S 向表面扩散,形成明显的富集,且表面氧和铀的原子浓度比明显下降。
2004, 33(11):1186-1190.
Abstract:
AlN-15BN composite ceramics were produced via pressureless sintering process with BN powders bought from market and AlN powders synthesized by carbothermal reduction method as starting materials, and Y2O3 as sintering aids. The effects of sintering temperature on the phases, density, microstructure of AlN-BN ceramics were studied. The results showed that Y2O3 reacted with Al2O3 presenting on the surfaces of AlN particles and formed liquid phases to promote the densification. The density, thermal conductivity and hardness increased with the increas of sintering temperature, and the plate-like BN crystalline could form a card-house structure which hampers the densification of composite ceramics. AlN-BN composite ceramics with thermal conductivity 104.2 W?m-1?K-1, relative density 86.4% and HRA hardness 562 MPa were produced after being sintering at 1 850 for 3 h.
AlN-15BN composite ceramics were produced via pressureless sintering process with BN powders bought from market and AlN powders synthesized by carbothermal reduction method as starting materials, and Y2O3 as sintering aids. The effects of sintering temperature on the phases, density, microstructure of AlN-BN ceramics were studied. The results showed that Y2O3 reacted with Al2O3 presenting on the surfaces of AlN particles and formed liquid phases to promote the densification. The density, thermal conductivity and hardness increased with the increas of sintering temperature, and the plate-like BN crystalline could form a card-house structure which hampers the densification of composite ceramics. AlN-BN composite ceramics with thermal conductivity 104.2 W?m-1?K-1, relative density 86.4% and HRA hardness 562 MPa were produced after being sintering at 1 850 for 3 h.
16 Effect of Surface Oxide Layer on the Activation Behavior of TiMn1.25Cr0.25 Hydrogen Storage Alloy
2004, 33(11):1191-1194.
Abstract:
The effect of surface oxide layer on the activation behavior of TiMn1.25Cr0.25 alloy is discussed through different exposure time to air prior to activation. The activation results imply that activation of TiMn1.25Cr0.25 alloy becomes more difficult with the time of exposure to air prolonging. The auger Electron Spectroscopy (AES) results present that an about 6 nm~10 nm thick oxide layer is formed on the surface of TiMn1.25Cr0.25 alloy, which is a important factor of effect the activation behavior of this alloy. The scanning electron microcopy (SEM) result show that the activation process of TiMn1.25Cr0.25 alloy is closely related with alloy grain fragmentation.
The effect of surface oxide layer on the activation behavior of TiMn1.25Cr0.25 alloy is discussed through different exposure time to air prior to activation. The activation results imply that activation of TiMn1.25Cr0.25 alloy becomes more difficult with the time of exposure to air prolonging. The auger Electron Spectroscopy (AES) results present that an about 6 nm~10 nm thick oxide layer is formed on the surface of TiMn1.25Cr0.25 alloy, which is a important factor of effect the activation behavior of this alloy. The scanning electron microcopy (SEM) result show that the activation process of TiMn1.25Cr0.25 alloy is closely related with alloy grain fragmentation.
2004, 33(11):1195-1198.
Abstract:
Cu film deposited on ZrN and TaN diffusion barriers is annealed in vacuum and H2, N2 mixed gas respectively. SEM morphology, XRD and resistivity are employed to characterize the thermal stability of the multilayer. The experiment demonstrates that for the multilayer deposited on the same kind of diffusion barrier, the thermal stability of multilayer annealed in H2, N2 mixed gas is superior to that annealed in vacuum. While for the multilayer annealed in vacuum, the thermal stability of the multilayer deposited on ZrN diffusion barrier is better than that deposited on TaN diffusion barrier. The investigation shows that the evaluation of the thermal stability of the multilayer should take not only some intrinsic factors of the multilayer itself, for instance diffusion barriers, but also the annealing ambient into account.
Cu film deposited on ZrN and TaN diffusion barriers is annealed in vacuum and H2, N2 mixed gas respectively. SEM morphology, XRD and resistivity are employed to characterize the thermal stability of the multilayer. The experiment demonstrates that for the multilayer deposited on the same kind of diffusion barrier, the thermal stability of multilayer annealed in H2, N2 mixed gas is superior to that annealed in vacuum. While for the multilayer annealed in vacuum, the thermal stability of the multilayer deposited on ZrN diffusion barrier is better than that deposited on TaN diffusion barrier. The investigation shows that the evaluation of the thermal stability of the multilayer should take not only some intrinsic factors of the multilayer itself, for instance diffusion barriers, but also the annealing ambient into account.
2004, 33(11):1199-1202.
Abstract:
The microstructure of Co-Cr-W alloy plasma surfacing has been investigated using metallurgical phase, X-ray diffraction, SEM and TEM. The results indicated that the alloy layer was composed of Co base solid solution with the preferred direction at (200) crystal plane and (Cr, Fe)7(C, B)3. The TEM research showed that there was a lot of stacking fault ribbons lying in Co-base solid solution. The result also showed that (Cr, Fe)7(C, B)3 was hexagonal lattice with lamellar and flake twin.
The microstructure of Co-Cr-W alloy plasma surfacing has been investigated using metallurgical phase, X-ray diffraction, SEM and TEM. The results indicated that the alloy layer was composed of Co base solid solution with the preferred direction at (200) crystal plane and (Cr, Fe)7(C, B)3. The TEM research showed that there was a lot of stacking fault ribbons lying in Co-base solid solution. The result also showed that (Cr, Fe)7(C, B)3 was hexagonal lattice with lamellar and flake twin.
2004, 33(11):1203-1205.
Abstract:
The Cu thin films on (111) of Si substrate were prepared by the co-sputtering equipment of ion beam enhance deposition, using the nano-indentation experiments, the elastic moduli and hardnesses of Cu films at different annealing temperature were obtained. The yield strength of Cu film was calculated by FEM model based on the nano-indentation experiments. It is found that yield strength of Cu film is much higher than that of bulk of Cu. And the annealing temperature affects the yield strength of film greatly. From XRD spectrum, it is analyzed that the decrease of yield strength of Cu film results from the change of crystal size and crystal plane.
The Cu thin films on (111) of Si substrate were prepared by the co-sputtering equipment of ion beam enhance deposition, using the nano-indentation experiments, the elastic moduli and hardnesses of Cu films at different annealing temperature were obtained. The yield strength of Cu film was calculated by FEM model based on the nano-indentation experiments. It is found that yield strength of Cu film is much higher than that of bulk of Cu. And the annealing temperature affects the yield strength of film greatly. From XRD spectrum, it is analyzed that the decrease of yield strength of Cu film results from the change of crystal size and crystal plane.
2004, 33(11):1206-1208.
Abstract:
OH radical is one of the reactive oxygen species, and is very oxidative. It can injure the body. Rare earth Ce3+ in cerium nitrate can change over between Ce3+ and Ce4+, and can react with OH radicals. In this study OH radicals were produced by nano-TiO2 which can produce OH radicals after irradiated by ultraviolet radiation. Cerium nitrate was mixed with nano-TiO2, then DMPO was employed to catch OH radicals. The result of electron spin resonance(ESR)shows that the quantity of OH radicals produced by nano-TiO2 mixed with cerium nitrate is much less than that without cerium nitrate, thus approves cerium nitrate can effectively rid OH radicals.
OH radical is one of the reactive oxygen species, and is very oxidative. It can injure the body. Rare earth Ce3+ in cerium nitrate can change over between Ce3+ and Ce4+, and can react with OH radicals. In this study OH radicals were produced by nano-TiO2 which can produce OH radicals after irradiated by ultraviolet radiation. Cerium nitrate was mixed with nano-TiO2, then DMPO was employed to catch OH radicals. The result of electron spin resonance(ESR)shows that the quantity of OH radicals produced by nano-TiO2 mixed with cerium nitrate is much less than that without cerium nitrate, thus approves cerium nitrate can effectively rid OH radicals.
2004, 33(11):1209-1212.
Abstract:
Using X-ray diffraction and the cross correlation method to determine the peak of diffraction plane (114), the residual stress distribution along the surface layer in the titanium alloy TC18 caused by shot peening was measured during step-by-step electrolytic dissolution. Relaxation of the compressive residual stress caused by shot peening at high temperatures and during cyclic stress was investigated. The characteristics of residual compressive stress field have also been analyzed; it was determined that the maximum compressive residual stress is a intrinsic parameter that is not affected by shot peening. From the above experimental results some practical laws have been derived, which offers a basis for the shot peening processing decision as it applies to the TC18 titanium alloy.
Using X-ray diffraction and the cross correlation method to determine the peak of diffraction plane (114), the residual stress distribution along the surface layer in the titanium alloy TC18 caused by shot peening was measured during step-by-step electrolytic dissolution. Relaxation of the compressive residual stress caused by shot peening at high temperatures and during cyclic stress was investigated. The characteristics of residual compressive stress field have also been analyzed; it was determined that the maximum compressive residual stress is a intrinsic parameter that is not affected by shot peening. From the above experimental results some practical laws have been derived, which offers a basis for the shot peening processing decision as it applies to the TC18 titanium alloy.
2004, 33(11):1213-1217.
Abstract:
The preparation method and arc erosion characteristics of the AgNi and AgSnO2 contacts materials which was fabricated by high-energy ball milling, hot pressing and sintering were studed. The powder morphology and microstructure of contact were analyzed by X-ray Diffraction (XRD), Scan Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The results shows that the grain size of composite powder has been fined, that the particle size of second phase was about 40 nm after high energy ball milling and the particles are dispersed in the Ag matrix in inlaying and welding, in witch the second phase aggregatin in the matrix and deposition on the grain bourdary that was caused by orthodox method has been abated. After hot pressing and annealing, there was not obviously growth of second phase and the particle size was about 50 nm. It was also found that the Ag film distributed on the grain boundary was retained in both contacts, which was propitious to the improvement of conductance capability. Compared with the commercial contacts, there was not obviously melting pool and splash of fused mass on the nanocomposite contact surface, which indicated that the arc on the contact surface was dispersed and the material was possessed of less are erosion in the arcing process.
The preparation method and arc erosion characteristics of the AgNi and AgSnO2 contacts materials which was fabricated by high-energy ball milling, hot pressing and sintering were studed. The powder morphology and microstructure of contact were analyzed by X-ray Diffraction (XRD), Scan Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The results shows that the grain size of composite powder has been fined, that the particle size of second phase was about 40 nm after high energy ball milling and the particles are dispersed in the Ag matrix in inlaying and welding, in witch the second phase aggregatin in the matrix and deposition on the grain bourdary that was caused by orthodox method has been abated. After hot pressing and annealing, there was not obviously growth of second phase and the particle size was about 50 nm. It was also found that the Ag film distributed on the grain boundary was retained in both contacts, which was propitious to the improvement of conductance capability. Compared with the commercial contacts, there was not obviously melting pool and splash of fused mass on the nanocomposite contact surface, which indicated that the arc on the contact surface was dispersed and the material was possessed of less are erosion in the arcing process.
2004, 33(11):1218-1221.
Abstract:
以CePO4与Ce-ZrO2等比例混合的含粘结剂的料浆为连接材料，在坯体状态下无压连接了可加工CePO4／Ce—ZrO2陶瓷与Ce-ZrO22陶瓷。对影响接点性能的工艺条件进行了讨论，材料的烧成温度和保温时间会明显影响连接效果，对25CePO4．Ce—ZrO2／Ce-ZrO2体系，在1450℃保温120min左右时，可实现最佳的连接效果。接点SEM分析表明，25CePO4/Ce—ZrO2和Ce-ZrO2连接体系中可形成结构均匀的扩散接点区域，其微观结构与母体材料的基本一致，接点的平均抗弯强度也与母体材料相似。用坯体无压连接法适合复杂形状本体或异体组合陶瓷构件，其工艺流程简单，加工成本低廉。
以CePO4与Ce-ZrO2等比例混合的含粘结剂的料浆为连接材料，在坯体状态下无压连接了可加工CePO4／Ce—ZrO2陶瓷与Ce-ZrO22陶瓷。对影响接点性能的工艺条件进行了讨论，材料的烧成温度和保温时间会明显影响连接效果，对25CePO4．Ce—ZrO2／Ce-ZrO2体系，在1450℃保温120min左右时，可实现最佳的连接效果。接点SEM分析表明，25CePO4/Ce—ZrO2和Ce-ZrO2连接体系中可形成结构均匀的扩散接点区域，其微观结构与母体材料的基本一致，接点的平均抗弯强度也与母体材料相似。用坯体无压连接法适合复杂形状本体或异体组合陶瓷构件，其工艺流程简单，加工成本低廉。
2004, 33(11):1222-1225.
Abstract:
The character of Sn-Zn-Ga solder alloy, including a series of properties tests, such as melting point, hardness, shear strength and solderability was studied. The results show that Ga element can decrease the melting point of solder alloys, but increase the melting range, and also reduce the hardness and shear strength of solder alloys. In addition, Ga element can enhance the wetting ability of solder alloys. The best composition of Sn-Zn-Ga lead-free solder alloy was obtained.
The character of Sn-Zn-Ga solder alloy, including a series of properties tests, such as melting point, hardness, shear strength and solderability was studied. The results show that Ga element can decrease the melting point of solder alloys, but increase the melting range, and also reduce the hardness and shear strength of solder alloys. In addition, Ga element can enhance the wetting ability of solder alloys. The best composition of Sn-Zn-Ga lead-free solder alloy was obtained.
2004, 33(11):1226-1228.
Abstract:
GaN films on Si substrates were obtained by hot-wall chemical vapor deposition and the growth condition during the process was investigated. The structure, surface morphology and the optical properties were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL). It indicated that hexagonal wurtzite GaN films were obtained on Si substrates. Preliminary results suggest that H2 as carrier gas play an important role at the same temperature in the growth of GaN films.
GaN films on Si substrates were obtained by hot-wall chemical vapor deposition and the growth condition during the process was investigated. The structure, surface morphology and the optical properties were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL). It indicated that hexagonal wurtzite GaN films were obtained on Si substrates. Preliminary results suggest that H2 as carrier gas play an important role at the same temperature in the growth of GaN films.
2004, 33(11):1229-1232.
Abstract:
系统研究了 NiTi 形状记忆合金表面电化学方法制备 HA 生物涂层过程中工艺参数对涂层相组成及其结构和形貌的影响,得出了最佳沉积规范,在该规范下沉积的涂层均由 CaHPO4·2H2O 组成,经碱处理后完全转变为 HA。所制备的 HA 涂层均匀致密,一定条件下涂层形貌由传统的针状转变为片层状。初步探讨了 HA 涂层形貌发生转变的机理。
系统研究了 NiTi 形状记忆合金表面电化学方法制备 HA 生物涂层过程中工艺参数对涂层相组成及其结构和形貌的影响,得出了最佳沉积规范,在该规范下沉积的涂层均由 CaHPO4·2H2O 组成,经碱处理后完全转变为 HA。所制备的 HA 涂层均匀致密,一定条件下涂层形貌由传统的针状转变为片层状。初步探讨了 HA 涂层形貌发生转变的机理。
