Volume 35,Issue 8,2006 Table of Contents
2006, 35(8):1177-1181.
Abstract:
This review article introduces the present research state of the Mg-B binary system, including a summary on phase species, phase transformation relationship, phase diagram and diffusion behavior between Mg and B. The key problems and significance on the research working were discussed. Finally, the potential research direction of Mg-B binary system was viewed.
This review article introduces the present research state of the Mg-B binary system, including a summary on phase species, phase transformation relationship, phase diagram and diffusion behavior between Mg and B. The key problems and significance on the research working were discussed. Finally, the potential research direction of Mg-B binary system was viewed.
2006, 35(8):1182-1186.
Abstract:
对[001]取向单晶镍基合金进行压应力处理，获P-型筏状结构后，对其进行拉伸蠕变性能测试及SEM形貌观察，研究了P-型筏状结构的粗化特征及影响因素。结果表明：由于应力场的差别，样品不同位置筏状γ＇相粗化程度及特征不同，近断口处筏状γ＇相扭曲且粗化程度加剧，随离断口距离增加，γ＇相粗化程度减弱。有限元分析认为：外加载荷改变了水平和垂直γ基体通道中的错配应力分布，并使立方γ＇相不同界面晶格发生挤压或扩张应变，这可以促进元素的互扩散和γ＇相的定向生长，是形成P-型筏状组织的主要原因。在高温及拉应力作用下，P-型γ＇相端部沿垂直于应力轴方向优先生长和相互横向连接，并进一步形成折叠的层状组织。
对[001]取向单晶镍基合金进行压应力处理，获P-型筏状结构后，对其进行拉伸蠕变性能测试及SEM形貌观察，研究了P-型筏状结构的粗化特征及影响因素。结果表明：由于应力场的差别，样品不同位置筏状γ＇相粗化程度及特征不同，近断口处筏状γ＇相扭曲且粗化程度加剧，随离断口距离增加，γ＇相粗化程度减弱。有限元分析认为：外加载荷改变了水平和垂直γ基体通道中的错配应力分布，并使立方γ＇相不同界面晶格发生挤压或扩张应变，这可以促进元素的互扩散和γ＇相的定向生长，是形成P-型筏状组织的主要原因。在高温及拉应力作用下，P-型γ＇相端部沿垂直于应力轴方向优先生长和相互横向连接，并进一步形成折叠的层状组织。
2006, 35(8):1187-1191.
Abstract:
Based on the TF(Thomas-Fermi)equation,the interior potential boundary condition under the electric field was established.Free energies were calculated under the influence of electric field with the defined boundary for the single atom,solid solution,compound and practical alloys.It can be concluded that the monatomic free energy under the electric field was not symmetrical about zero point of the external potential.The free energy sensitivities of the three calculated elements on the side of positive electric field take turns of Al,Li,and Mg,and take turns of Al,Mg and Li on the side of negative electric field.The free energies of Al3Li compound and Al-2.14%Li solid solution exhibit different electric field symmetries and sensitivities in the electric field,and the Al-2.14%Li is more sensitive than the Al3Li at 460 K and 800 K.The free energy of solid solution Al-2.14%Li is higher than the compound Al3Li at 800 K under higher electric field,the free energy of Al3Li is lower than Al-2.14%Li at 460 K.The free energy of 1420 alloy is symmetrical about the zero external potential,consistent with its tensile properties during aging process in the electric-field.
Based on the TF(Thomas-Fermi)equation,the interior potential boundary condition under the electric field was established.Free energies were calculated under the influence of electric field with the defined boundary for the single atom,solid solution,compound and practical alloys.It can be concluded that the monatomic free energy under the electric field was not symmetrical about zero point of the external potential.The free energy sensitivities of the three calculated elements on the side of positive electric field take turns of Al,Li,and Mg,and take turns of Al,Mg and Li on the side of negative electric field.The free energies of Al3Li compound and Al-2.14%Li solid solution exhibit different electric field symmetries and sensitivities in the electric field,and the Al-2.14%Li is more sensitive than the Al3Li at 460 K and 800 K.The free energy of solid solution Al-2.14%Li is higher than the compound Al3Li at 800 K under higher electric field,the free energy of Al3Li is lower than Al-2.14%Li at 460 K.The free energy of 1420 alloy is symmetrical about the zero external potential,consistent with its tensile properties during aging process in the electric-field.
2006, 35(8):1192-1194.
Abstract:
利用超高真空电子束蒸发法制备了可替代SiO2作为栅介质的HfAlO膜.薄膜的化学组成为(HfO2)(Al2O3)2,900℃退火处理后仍然呈现非晶状态,而且表面平滑.介电常数为12.7,等效氧化物厚度2 nm,固定电荷密度4×1012cm-2,2 C栅偏压下漏电流为0.04 m A/cm2.后退火处理能有效降低固定电荷密度和泄漏电流密度,但会造成界面SiO2的生长.
利用超高真空电子束蒸发法制备了可替代SiO2作为栅介质的HfAlO膜.薄膜的化学组成为(HfO2)(Al2O3)2,900℃退火处理后仍然呈现非晶状态,而且表面平滑.介电常数为12.7,等效氧化物厚度2 nm,固定电荷密度4×1012cm-2,2 C栅偏压下漏电流为0.04 m A/cm2.后退火处理能有效降低固定电荷密度和泄漏电流密度,但会造成界面SiO2的生长.
2006, 35(8):1195-1198.
Abstract:
在常温常压下，以Cu-Zn—Al合金为基体经过简单的化学处理，在基体上成功地合成了直径为几十纳米，长度在微米量级的Si-维纳米结构。利用TEM，HREM，EDS等测试手段对Si-维纳米结构的形貌和微观结构进行了表征。观察到Cu-Zn-Al合金中存在着运动的“非线性振荡胞区”，并且发现Si-维纳米结构的生长和形貌与这些胞区的运动有着密切的关系。另外，对于Si-维纳米结构生长机制进行了初步探讨。
在常温常压下，以Cu-Zn—Al合金为基体经过简单的化学处理，在基体上成功地合成了直径为几十纳米，长度在微米量级的Si-维纳米结构。利用TEM，HREM，EDS等测试手段对Si-维纳米结构的形貌和微观结构进行了表征。观察到Cu-Zn-Al合金中存在着运动的“非线性振荡胞区”，并且发现Si-维纳米结构的生长和形貌与这些胞区的运动有着密切的关系。另外，对于Si-维纳米结构生长机制进行了初步探讨。
6 Effect of Small Content of Tungsten on Microstructure of As-Cast and As-Annealed Ti-Al-Nb-B-W Alloy
2006, 35(8):1199-1203.
Abstract:
对铸态及经过热等静压和均匀化处理后Ti-Al-Nb-B-W合金的微观组织进行了观察和分析，研究了元素钨对Ti—Al-Nb—B—W合金的铸态及均匀化处理态微观组织的影响。结果发现：随着钨含量的增加，Ti-Al-Nb-B-W合金铸态组织中的非平衡状态加剧，网状组织和胞状组织越来越发达；随着钨含量的增加，Ti-Al-Nb-B-W合金铸态组织中的显微缩松有增多的趋势：在Ti—Al—Nb—B-w合金的均匀化处理过程中发生了非连续粗化，钨不影响7等轴晶的形核位置与尺寸，但影响其形核率，随着钨含量的增加，7等轴晶的体积分数有增加的趋势；Ti-Al-Nb-B-W合金经过均匀化处理后，随着钨含量的增加，其片层组织更加完善，片层间距更加细小；Ti-Al-Nb-B-W合金经过均匀化处理后，随着钨含量的增加，β（B2）相析出的量更多。
对铸态及经过热等静压和均匀化处理后Ti-Al-Nb-B-W合金的微观组织进行了观察和分析，研究了元素钨对Ti—Al-Nb—B—W合金的铸态及均匀化处理态微观组织的影响。结果发现：随着钨含量的增加，Ti-Al-Nb-B-W合金铸态组织中的非平衡状态加剧，网状组织和胞状组织越来越发达；随着钨含量的增加，Ti-Al-Nb-B-W合金铸态组织中的显微缩松有增多的趋势：在Ti—Al—Nb—B-w合金的均匀化处理过程中发生了非连续粗化，钨不影响7等轴晶的形核位置与尺寸，但影响其形核率，随着钨含量的增加，7等轴晶的体积分数有增加的趋势；Ti-Al-Nb-B-W合金经过均匀化处理后，随着钨含量的增加，其片层组织更加完善，片层间距更加细小；Ti-Al-Nb-B-W合金经过均匀化处理后，随着钨含量的增加，β（B2）相析出的量更多。
2006, 35(8):1204-1207.
Abstract:
碳/碳复合材料既有良好的生物相容性,又有良好的力学性能,是一种极具潜力的新型生物材料。为提高其硬度、耐磨性,降低摩擦系数,需对其表面进行处理。本研究先利用包埋法在其表面制备SiC涂层,后利用非平衡磁控溅射技术在SiC涂层表面制备了掺铬碳膜。通过XRD,Raman,SEM,EDAX和XPS对其结构和形貌进行了表征,用MM-200型环块磨损试验机对膜的摩擦学性能进行了测定。研究结果表明:掺铬碳膜在XRD及拉曼光谱上都没有明显的峰,为非晶态结构。碳原子主要为类石墨碳。非晶态掺铬碳膜的摩擦系数约为0.100,比碳/碳复合材料低;磨损率为0.45×10-6mm3·(Nm)-1,也比碳/碳复合材料低。
碳/碳复合材料既有良好的生物相容性,又有良好的力学性能,是一种极具潜力的新型生物材料。为提高其硬度、耐磨性,降低摩擦系数,需对其表面进行处理。本研究先利用包埋法在其表面制备SiC涂层,后利用非平衡磁控溅射技术在SiC涂层表面制备了掺铬碳膜。通过XRD,Raman,SEM,EDAX和XPS对其结构和形貌进行了表征,用MM-200型环块磨损试验机对膜的摩擦学性能进行了测定。研究结果表明:掺铬碳膜在XRD及拉曼光谱上都没有明显的峰,为非晶态结构。碳原子主要为类石墨碳。非晶态掺铬碳膜的摩擦系数约为0.100,比碳/碳复合材料低;磨损率为0.45×10-6mm3·(Nm)-1,也比碳/碳复合材料低。
2006, 35(8):1208-1210.
Abstract:
The undercoolings of Ni-coating melt with different temperatures were in situ tested within differential scanning calorimeter facility by a flux technique. The highest undercooling obtained in this way was 411 K. The undercooling increased with the increasing of cooling rate in rang of 10 K/min-50 K/rain and melt treatment temperature at the same cooling rate, then held a constant. The relationships between crystallize rate and temperature as well as cooling rate and time were analyzed. It shows that a faster cooling rate results in a shorter time needed to finish the melt crystallization.
The undercoolings of Ni-coating melt with different temperatures were in situ tested within differential scanning calorimeter facility by a flux technique. The highest undercooling obtained in this way was 411 K. The undercooling increased with the increasing of cooling rate in rang of 10 K/min-50 K/rain and melt treatment temperature at the same cooling rate, then held a constant. The relationships between crystallize rate and temperature as well as cooling rate and time were analyzed. It shows that a faster cooling rate results in a shorter time needed to finish the melt crystallization.
9 Synthesis of IR Sensitive Material CaS:Eu,Sm by Low-Temperature Combustion and Its Characterization
2006, 35(8):1211-1214.
Abstract:
以金属硝酸盐．尿素作为原料体系，引入了升华硫粉，通过低温燃烧法一步合成了硫化物体系红外响应材料。对硝酸盐．尿素体系的低温燃烧过程进行了分析，根据氧化．还原反应的化合价理论计算了尿素燃料的理论用量。燃烧点火温度为600℃，反应时间为2min～3min，产物为红色云层状疏松多孔的纳米粉末，粒径为36nm左右。对样品进行XRD物相分析证明产物为CaS晶相，面心立方结构。光谱分析表明：自然光可以有效激发样品使之储能：样品在800nm～1600nm之间具有宽光谱红外响应效应：红外转换发光峰值波长位于655nm，对应于Eu^2＋离子的4f^65d→4f^7（^8S7/2）跃迁。
以金属硝酸盐．尿素作为原料体系，引入了升华硫粉，通过低温燃烧法一步合成了硫化物体系红外响应材料。对硝酸盐．尿素体系的低温燃烧过程进行了分析，根据氧化．还原反应的化合价理论计算了尿素燃料的理论用量。燃烧点火温度为600℃，反应时间为2min～3min，产物为红色云层状疏松多孔的纳米粉末，粒径为36nm左右。对样品进行XRD物相分析证明产物为CaS晶相，面心立方结构。光谱分析表明：自然光可以有效激发样品使之储能：样品在800nm～1600nm之间具有宽光谱红外响应效应：红外转换发光峰值波长位于655nm，对应于Eu^2＋离子的4f^65d→4f^7（^8S7/2）跃迁。
2006, 35(8):1215-1218.
Abstract:
通过扫描电镜、能谱仪、X射线衍射仪研究了Ag-Cu-Ti钎料中的活性元素Ti在钎料与立方氮化硼（CBN）磨粒高温钎焊结合界面的扩散现象，并运用动力学分析对界面反应层的生长过程及反应激活能进行了探讨。结果表明：钎焊过程中，钎料中的活性元素Ti明显向磨粒侧扩散偏聚并发生化学反应，实现了磨粒与基体材料的牢固结合；钎焊CBN磨粒表面生成的TiB2和TiN化合物形貌接近平衡状态下生长的理想形貌；界面反应层在钎焊温度1153K～1193K，保温时间5min～20min之间依据抛物线生长法则所得扩散激活能值表明其生长过程主要受新生TiN影响。
通过扫描电镜、能谱仪、X射线衍射仪研究了Ag-Cu-Ti钎料中的活性元素Ti在钎料与立方氮化硼（CBN）磨粒高温钎焊结合界面的扩散现象，并运用动力学分析对界面反应层的生长过程及反应激活能进行了探讨。结果表明：钎焊过程中，钎料中的活性元素Ti明显向磨粒侧扩散偏聚并发生化学反应，实现了磨粒与基体材料的牢固结合；钎焊CBN磨粒表面生成的TiB2和TiN化合物形貌接近平衡状态下生长的理想形貌；界面反应层在钎焊温度1153K～1193K，保温时间5min～20min之间依据抛物线生长法则所得扩散激活能值表明其生长过程主要受新生TiN影响。
2006, 35(8):1219-1222.
Abstract:
The corrosion behavior of titanium in hydrogen peroxide solutions was studied by measuring the titanium ions concentration using spectrophotometer.The influence of additives(K+,Ca2+,Na+,Mg2+,Cl-,HPO42-,H2PO4-)on the corrosion behavior of titanium was discussed under different pH conditions.The results indicated that Ca2+ exhibited the highest inhibition to the titanium corrosion in hydrogen peroxide solutions.However,HPO42-behaved as an accelerator to the corrosion.It was considered that the Ca2+ inhibited the titanium corrosion probably by absorbed on the titanium surface to form a thin film of CaTiO3 or CaO2.The HPO42-accelerated the titanium corrosion,however,probably by increasing the defects of surface oxide films after absorption on the titanium surface.
The corrosion behavior of titanium in hydrogen peroxide solutions was studied by measuring the titanium ions concentration using spectrophotometer.The influence of additives(K+,Ca2+,Na+,Mg2+,Cl-,HPO42-,H2PO4-)on the corrosion behavior of titanium was discussed under different pH conditions.The results indicated that Ca2+ exhibited the highest inhibition to the titanium corrosion in hydrogen peroxide solutions.However,HPO42-behaved as an accelerator to the corrosion.It was considered that the Ca2+ inhibited the titanium corrosion probably by absorbed on the titanium surface to form a thin film of CaTiO3 or CaO2.The HPO42-accelerated the titanium corrosion,however,probably by increasing the defects of surface oxide films after absorption on the titanium surface.
2006, 35(8):1223-1227.
Abstract:
Novel nanosized sulfur-containing composite cathode materials were synthesized by heating the mixture of sublimed sulfur and multi-walled carbon nanotubes(MWNTs)in certain conditions.The structure and morphology of the composite cathode materials were determined by scanning electron microscopy.The electrochemical performances of the MWNTs-sulfur composite(MSC)were characterized by charge-discharge characteristic,cyclic voltammetry and electrochemical impedance spectroscopy.The results indicate that the MSC exhibits a good rate capability,a satisfactory capacity,and acceptable cycle-life characteristics.The specific capacity was more than 700 mAh/g for the first discharge,and remained at 464 mAh/g,just 34% less after 60 cycles at room temperature.
Novel nanosized sulfur-containing composite cathode materials were synthesized by heating the mixture of sublimed sulfur and multi-walled carbon nanotubes(MWNTs)in certain conditions.The structure and morphology of the composite cathode materials were determined by scanning electron microscopy.The electrochemical performances of the MWNTs-sulfur composite(MSC)were characterized by charge-discharge characteristic,cyclic voltammetry and electrochemical impedance spectroscopy.The results indicate that the MSC exhibits a good rate capability,a satisfactory capacity,and acceptable cycle-life characteristics.The specific capacity was more than 700 mAh/g for the first discharge,and remained at 464 mAh/g,just 34% less after 60 cycles at room temperature.
2006, 35(8):1228-1230.
Abstract:
采用三元扩散偶技术测定了Ni—Fe—Mo三元系1373Ni—Fe—Mo三元扩散偶的相区成分，并对其相关系进行了研究。K的等温截面，借助电子探针微区成分分析方法分析了测得Ni-Fe-Mo三元扩散偶在1373K下存在2个二元中间化合物：μ和NiMo。该三元系在1373K存在3个三相区：μ＋bcc（Mo）＋NiMo；μ＋NiMo＋fcc；bcc（Fe）＋μ＋fcc：在此温度的扩散偶中未发现三元中间化合物。
采用三元扩散偶技术测定了Ni—Fe—Mo三元系1373Ni—Fe—Mo三元扩散偶的相区成分，并对其相关系进行了研究。K的等温截面，借助电子探针微区成分分析方法分析了测得Ni-Fe-Mo三元扩散偶在1373K下存在2个二元中间化合物：μ和NiMo。该三元系在1373K存在3个三相区：μ＋bcc（Mo）＋NiMo；μ＋NiMo＋fcc；bcc（Fe）＋μ＋fcc：在此温度的扩散偶中未发现三元中间化合物。
2006, 35(8):1231-1234.
Abstract:
The effects of Re on the tensile and stress-rupture properties and fracture behaviour of a single crystal superalloy containing Re were studied. Tensile specimens were prepared from this single-crystal with [001 ] orientation. The fractograph was examined by means of scanning electron microscope. The test specimens had the [001 ] growth direction parallel to the loading axis in tension. The results of the present investigation indicate that the tensile elongation of single crystal superalloy significantly decreased, but the stress-rupture elongation at high temperature increased with Re addition. The fractograph of fracture surface for the tensile specimen at room temperature showed a slide fracturing mode. The fractograph at elevated temperature showed a creep rupture mode with uneven deformation. The fractograph of fracture surface for the stress rupture specimen showed a typically ductile fracturing mode and the deformation was even.
The effects of Re on the tensile and stress-rupture properties and fracture behaviour of a single crystal superalloy containing Re were studied. Tensile specimens were prepared from this single-crystal with [001 ] orientation. The fractograph was examined by means of scanning electron microscope. The test specimens had the [001 ] growth direction parallel to the loading axis in tension. The results of the present investigation indicate that the tensile elongation of single crystal superalloy significantly decreased, but the stress-rupture elongation at high temperature increased with Re addition. The fractograph of fracture surface for the tensile specimen at room temperature showed a slide fracturing mode. The fractograph at elevated temperature showed a creep rupture mode with uneven deformation. The fractograph of fracture surface for the stress rupture specimen showed a typically ductile fracturing mode and the deformation was even.
2006, 35(8):1235-1238.
Abstract:
采用X射线衍射仪(XRD),扫描电子显微镜(SEM),维氏硬度计,电子万能材料试验机,动态热模拟机研究了稀土/MoSi2复合材料的结构、形貌、硬度、断裂韧性、高温屈服强度、强韧化机理等.结果表明在MoSi2中添加适量的La2O3,可起到室温强韧化和高温强化作用.随着La2O3含量的增加,样品的硬度、断裂韧性呈先增后减的规律,其最大值分别为10.85 GPa,7.25 MPa·m1/2.该材料的强化机制为细晶和优化晶界强化;韧化机制为细晶韧化,裂纹偏转、微桥接和弯曲韧化.
采用X射线衍射仪(XRD),扫描电子显微镜(SEM),维氏硬度计,电子万能材料试验机,动态热模拟机研究了稀土/MoSi2复合材料的结构、形貌、硬度、断裂韧性、高温屈服强度、强韧化机理等.结果表明在MoSi2中添加适量的La2O3,可起到室温强韧化和高温强化作用.随着La2O3含量的增加,样品的硬度、断裂韧性呈先增后减的规律,其最大值分别为10.85 GPa,7.25 MPa·m1/2.该材料的强化机制为细晶和优化晶界强化;韧化机制为细晶韧化,裂纹偏转、微桥接和弯曲韧化.
2006, 35(8):1239-1242.
Abstract:
采用双层辉光等离子冶金技术在纯钛表面制备了Ti—Pd合金层。其深度大约为90μm，Pd含量呈梯度变化，并出现了TiPd3，TiPd2，Ti2Pd3，Ti3Pd5，TiPd，Ti4Pd等6种化合物相和Pd相。合金层在100℃的NaCl饱和溶液＋HCl溶液以及40℃的8．6％H2SO4溶液中的耐缝隙腐蚀性能优于Ti0．2Pd合金；在室温80％H2SO4的溶液中，腐蚀速率仅为0．682mm／a，是Ti0．2Pd合金的18．2％：在室温30％HCl的溶液中，表面Ti—Pd的腐蚀速率仅为0．004mm／a，是Ti0．2Pd合金的12．5％。
采用双层辉光等离子冶金技术在纯钛表面制备了Ti—Pd合金层。其深度大约为90μm，Pd含量呈梯度变化，并出现了TiPd3，TiPd2，Ti2Pd3，Ti3Pd5，TiPd，Ti4Pd等6种化合物相和Pd相。合金层在100℃的NaCl饱和溶液＋HCl溶液以及40℃的8．6％H2SO4溶液中的耐缝隙腐蚀性能优于Ti0．2Pd合金；在室温80％H2SO4的溶液中，腐蚀速率仅为0．682mm／a，是Ti0．2Pd合金的18．2％：在室温30％HCl的溶液中，表面Ti—Pd的腐蚀速率仅为0．004mm／a，是Ti0．2Pd合金的12．5％。
2006, 35(8):1243-1246.
Abstract:
Using pre-alloying Ta-W-Hf powder,Ta-W-Hf bulk alloys were prepared by means of CIP(cold isostatic press),HIP(hot isostatic press)and high temperature annealing.This paper is focused on the influences of HIP and high temperature annealing on the alloy performances.The results show that high strength,high hardness and low plasticity appear for the alloy after HIP at low temperature.The elongation and section shrinking would be largely improved and the strength would be decreased after HIP at high temperature or high temperature annealing due to the oxygen element's inhomogeneous distribution in the raw material particles and remaining in the bulk after HIP to form the hidden harden cell structures without phase change in these regions.These cell structures would disappear after high temperature annealing.
Using pre-alloying Ta-W-Hf powder,Ta-W-Hf bulk alloys were prepared by means of CIP(cold isostatic press),HIP(hot isostatic press)and high temperature annealing.This paper is focused on the influences of HIP and high temperature annealing on the alloy performances.The results show that high strength,high hardness and low plasticity appear for the alloy after HIP at low temperature.The elongation and section shrinking would be largely improved and the strength would be decreased after HIP at high temperature or high temperature annealing due to the oxygen element's inhomogeneous distribution in the raw material particles and remaining in the bulk after HIP to form the hidden harden cell structures without phase change in these regions.These cell structures would disappear after high temperature annealing.
2006, 35(8):1247-1250.
Abstract:
采用水溶液沉淀法成功制备了晶粒尺寸约为16．7nm的纳米LaF3粉体。采用真空（10^-4Pa）压结法（1GPa）制成纳米LaF3块体。用XRD分析测试了不同退火温度下纳米LaF3块体的晶粒尺寸。结果表明，随着退火温度的升高，纳米LaF3块体的晶粒尺寸增大，从原始晶粒尺寸16．7nm长大到900℃时的92．6nm。同时在不同升温速率下测量纳米LaF3块体的DSC曲线，并由Kissinger方程求得其晶粒长大激活能为2．01eV。
采用水溶液沉淀法成功制备了晶粒尺寸约为16．7nm的纳米LaF3粉体。采用真空（10^-4Pa）压结法（1GPa）制成纳米LaF3块体。用XRD分析测试了不同退火温度下纳米LaF3块体的晶粒尺寸。结果表明，随着退火温度的升高，纳米LaF3块体的晶粒尺寸增大，从原始晶粒尺寸16．7nm长大到900℃时的92．6nm。同时在不同升温速率下测量纳米LaF3块体的DSC曲线，并由Kissinger方程求得其晶粒长大激活能为2．01eV。
2006, 35(8):1251-1253.
Abstract:
对于磁制冷GdDyFe铸锭复合材料和快淬得到的纳米晶薄带的结构和磁热效应进行了研究和分析。结果表明，GdDyFe铸锭样品和纳米晶薄带样品的居里温度比GdDy合金高，分别由原来的260K升高到了275K和263K，并保留了较大的磁熵变。而且几种相变温度各不相同的铁磁物质复合的GdDyFe材料及其薄带样品的纳米晶结构使得样品的高磁熵变温区范围宽化。该材料适用于埃里克森循环，为磁制冷材料的实用化带来了希望。
对于磁制冷GdDyFe铸锭复合材料和快淬得到的纳米晶薄带的结构和磁热效应进行了研究和分析。结果表明，GdDyFe铸锭样品和纳米晶薄带样品的居里温度比GdDy合金高，分别由原来的260K升高到了275K和263K，并保留了较大的磁熵变。而且几种相变温度各不相同的铁磁物质复合的GdDyFe材料及其薄带样品的纳米晶结构使得样品的高磁熵变温区范围宽化。该材料适用于埃里克森循环，为磁制冷材料的实用化带来了希望。
2006, 35(8):1254-1257.
Abstract:
The change of microstructure and its influences on the micro-hardness and compression properties of Zr57Cu15.4Ni12.6Al10Nb5 bulk amorphous alloy with isothermal heat treatment have been studied by X-ray diffractometer, scanning electronic microscope, micro-hardness tester and compression experiment. It has been found that as the heating time increases, the crystallization temperature of the amorphous alloy will decrease. The phase decomposition and/or partial crystallization will cause the micro-hardness to increase and the compression strength to decrease rapidly, and make the fracture mode of amorphous alloys changing to that of crystalline alloys.
The change of microstructure and its influences on the micro-hardness and compression properties of Zr57Cu15.4Ni12.6Al10Nb5 bulk amorphous alloy with isothermal heat treatment have been studied by X-ray diffractometer, scanning electronic microscope, micro-hardness tester and compression experiment. It has been found that as the heating time increases, the crystallization temperature of the amorphous alloy will decrease. The phase decomposition and/or partial crystallization will cause the micro-hardness to increase and the compression strength to decrease rapidly, and make the fracture mode of amorphous alloys changing to that of crystalline alloys.
2006, 35(8):1258-1262.
Abstract:
Based on the SHS Reactive Flame Spray technology, TiC-TiB2 multiphase ceramic coatings were prepared in the Ti-B4C-C reactive system. Water quenching experiments were used to intercept the intermediate states of the flying particles during the spray course. The macroscopical characteristics, composition, structure, and transforming course of the intermediate-stated reactive products in different flying distance were observed, and the flying combustion course and reactive mechanism of the spray agglomerates in the oxyacetylene flame were discussed. It was showed that there were four types of intermediate-stated reactive products according to their macroscopical characteristics, which were the fully molten solid and hollow ceramic beads, the ceramic particles with molten surface whereas the un-molten core and the completely un-molten ceramic particles. The flying combustion mechanism is studied. The SHS reaction began with the melting of Ti powders. The combustion synthesis of the relatively small spray agglomerates in the core of the oxyacetylene flame was controlled by the diffusion and capillary mechanism and took place in the deflagration mode, whereas the combustion synthesis of the relatively big spray agglomerates in the periphery of the oxyacetylene flame was controlled by the ingredient melting and separating out mechanism.
Based on the SHS Reactive Flame Spray technology, TiC-TiB2 multiphase ceramic coatings were prepared in the Ti-B4C-C reactive system. Water quenching experiments were used to intercept the intermediate states of the flying particles during the spray course. The macroscopical characteristics, composition, structure, and transforming course of the intermediate-stated reactive products in different flying distance were observed, and the flying combustion course and reactive mechanism of the spray agglomerates in the oxyacetylene flame were discussed. It was showed that there were four types of intermediate-stated reactive products according to their macroscopical characteristics, which were the fully molten solid and hollow ceramic beads, the ceramic particles with molten surface whereas the un-molten core and the completely un-molten ceramic particles. The flying combustion mechanism is studied. The SHS reaction began with the melting of Ti powders. The combustion synthesis of the relatively small spray agglomerates in the core of the oxyacetylene flame was controlled by the diffusion and capillary mechanism and took place in the deflagration mode, whereas the combustion synthesis of the relatively big spray agglomerates in the periphery of the oxyacetylene flame was controlled by the ingredient melting and separating out mechanism.
2006, 35(8):1263-1267.
Abstract:
Effect of magnetic field on the shape and crystalstructure of nano MnZn ferrite precursor prepared by co-precipitation way was studied by using SEM, XRD, TEM and TG. It was shown that the morphology of nano particles would change from spheric to chain-like with increasing the magnetic field to a certain critical value. The claviform-like nano particles obtained in a magnetic field of 10 T showed the structure information of single crystal. Thermal gravity curve revealed that the activity of nano particles was reduced in a magnetic field of 10 T due to the increase of one dimension size. The mechanism of magnetic field effect on the nano particle nucleation and growth was discussed by crystal growth theory.
Effect of magnetic field on the shape and crystalstructure of nano MnZn ferrite precursor prepared by co-precipitation way was studied by using SEM, XRD, TEM and TG. It was shown that the morphology of nano particles would change from spheric to chain-like with increasing the magnetic field to a certain critical value. The claviform-like nano particles obtained in a magnetic field of 10 T showed the structure information of single crystal. Thermal gravity curve revealed that the activity of nano particles was reduced in a magnetic field of 10 T due to the increase of one dimension size. The mechanism of magnetic field effect on the nano particle nucleation and growth was discussed by crystal growth theory.
2006, 35(8):1268-1271.
Abstract:
The changes in phase structure and hydrogen storage properties of Ti0.9Zr0.1Mn1.5 alloy after modification by mechanical ball-milling for different time(t = 0 min,10 min,30 min,60 min)were investigated systematically.The XRD and SEM analysis show that all of the as-cast and ball-milled alloys consist of a single C14 type Laves phase with hexagonal structure.The ball-milled alloy powders appear aggregation to some extent,the particle size decreases and the activation behaviour is improved with the increase of ball-milling time for the alloy.It is found that the as-cast alloy is activated after 4 hydriding/dehydriding cycles,and its maximum hydrogen absorption capacity and effective hydrogen desorption capacity at room temperature are 209.3 ml/g and 157.6 ml/g,respectively,and the efficiency of hydrogen desorption/absorption is 75.3%.The maximum hydrogen absorption capacity and the effective hydrogen desorption capacity increase firstly then decrease at room temperature with the maximum values of 231.4 ml/g and 203.8 ml/g at t=30 min,respectively,while,its efficiency of hydrogen desorption/absorption reaches 88.1%.This shows that the overall properties of Ti0.9Zr0.1Mn1.5 alloy can be improved effectively by ball-milling.
The changes in phase structure and hydrogen storage properties of Ti0.9Zr0.1Mn1.5 alloy after modification by mechanical ball-milling for different time(t = 0 min,10 min,30 min,60 min)were investigated systematically.The XRD and SEM analysis show that all of the as-cast and ball-milled alloys consist of a single C14 type Laves phase with hexagonal structure.The ball-milled alloy powders appear aggregation to some extent,the particle size decreases and the activation behaviour is improved with the increase of ball-milling time for the alloy.It is found that the as-cast alloy is activated after 4 hydriding/dehydriding cycles,and its maximum hydrogen absorption capacity and effective hydrogen desorption capacity at room temperature are 209.3 ml/g and 157.6 ml/g,respectively,and the efficiency of hydrogen desorption/absorption is 75.3%.The maximum hydrogen absorption capacity and the effective hydrogen desorption capacity increase firstly then decrease at room temperature with the maximum values of 231.4 ml/g and 203.8 ml/g at t=30 min,respectively,while,its efficiency of hydrogen desorption/absorption reaches 88.1%.This shows that the overall properties of Ti0.9Zr0.1Mn1.5 alloy can be improved effectively by ball-milling.
2006, 35(8):1276-1279.
Abstract:
The mechanical properties, electrical conductivity and microstructures of 7055 aluminum alloy in various cold rolling reductions and tempers were investigated on the basis of tensile test, optical microscopy, X-ray diffraction and TEM. The results showed that the strength of 7055 alloy could be increased slightly after cold rolling and T6 aging at a smaller reduction, then decreased at a heavier rolling reduction, and always reduced with the increase of rolling reduction for the RRA temper alloy. The electrical conductivity of cold rolled 7055 alloy decreased with the increase of rolling reduction and increased for T6 and RRA temper alloys due to the lattice distortion and coarse precipitates from dislocations.
The mechanical properties, electrical conductivity and microstructures of 7055 aluminum alloy in various cold rolling reductions and tempers were investigated on the basis of tensile test, optical microscopy, X-ray diffraction and TEM. The results showed that the strength of 7055 alloy could be increased slightly after cold rolling and T6 aging at a smaller reduction, then decreased at a heavier rolling reduction, and always reduced with the increase of rolling reduction for the RRA temper alloy. The electrical conductivity of cold rolled 7055 alloy decreased with the increase of rolling reduction and increased for T6 and RRA temper alloys due to the lattice distortion and coarse precipitates from dislocations.
2006, 35(8):1280-1284.
Abstract:
Corrosion process of the anodized film on AZ91D magnesium alloy's surface in 3.5% NaCl aqueous solution was investigated with electrochemical impedance spectroscopy(EIS).According to the characteristic of EIS in the corrosion process,the EIS of anodized film at the initiation stage and at the propagation stage of pitting corrosion were simulated using the equivalent circuit of R(RQ)(RQ)and R(Q(R(RQ)))models,respectively.The results show that the solution resistance Rsol and the Yp of porous layer increased,and the resistance Rp of porous layer and the resistance Rb of dense layer decreased gradually.The np value almost unchanged and the Yb and nb of dense layer have no obvious regularity with prolonged of immersion time at the initiation stage of pitting corrosion.The solution resistance Rsol,the n1 value and the reaction resistance R2 in corrosion pit decreased,while the Y1 increased,the solution resistance R1,the Y2 and n2 of metal/medium interface for the anode in corrosion pit have no substantial regularity with prolonging the immersion time at the propagation stage of pitting corrosion.
Corrosion process of the anodized film on AZ91D magnesium alloy's surface in 3.5% NaCl aqueous solution was investigated with electrochemical impedance spectroscopy(EIS).According to the characteristic of EIS in the corrosion process,the EIS of anodized film at the initiation stage and at the propagation stage of pitting corrosion were simulated using the equivalent circuit of R(RQ)(RQ)and R(Q(R(RQ)))models,respectively.The results show that the solution resistance Rsol and the Yp of porous layer increased,and the resistance Rp of porous layer and the resistance Rb of dense layer decreased gradually.The np value almost unchanged and the Yb and nb of dense layer have no obvious regularity with prolonged of immersion time at the initiation stage of pitting corrosion.The solution resistance Rsol,the n1 value and the reaction resistance R2 in corrosion pit decreased,while the Y1 increased,the solution resistance R1,the Y2 and n2 of metal/medium interface for the anode in corrosion pit have no substantial regularity with prolonging the immersion time at the propagation stage of pitting corrosion.
2006, 35(8):1289-1293.
Abstract:
The microstructures and solidification processes of CuCr25 alloys are studied under different cooling rates in the present paper.With increasing of the cooling rate,the microstructures of CuCr25 alloys become finer and finer.When the cooling rate is up to 107K/s,nano-microstructures can be obtained.When the cooling rate is <103K/s,the solidification process of CuCr25 alloys belongs to a general solidification process;if the cooling rate is >104K/s,it belongs to the liquid phase separation process.In rapid solidification process,there is no new phase formed in CuCr25 alloys,but the solubility of Cu in Cr-rich phase and Cr in Cu-rich phase will increase.
The microstructures and solidification processes of CuCr25 alloys are studied under different cooling rates in the present paper.With increasing of the cooling rate,the microstructures of CuCr25 alloys become finer and finer.When the cooling rate is up to 107K/s,nano-microstructures can be obtained.When the cooling rate is <103K/s,the solidification process of CuCr25 alloys belongs to a general solidification process;if the cooling rate is >104K/s,it belongs to the liquid phase separation process.In rapid solidification process,there is no new phase formed in CuCr25 alloys,but the solubility of Cu in Cr-rich phase and Cr in Cu-rich phase will increase.
Wang Donglin
,
Li Jiabao
,
Jin Tao
,
Wei Zheng
,
Hu Zhuangqi
,
Fu Liqun
,
Liu Shifeng Corporation Ltd.
,
Shenyang
,
China;. Shenyang Occupational Technical College
,
Shenyang
,
China)
2006, 35(8):1294-1298.
Abstract:
K417镍基高温合金是我国广泛应用于制造航空发动机涡轮叶片的材料。研究了采用喷丸再结晶方法提高K417合金疲劳寿命的可行性。实验结果表明，该方法可以有效提高K417合金在650℃大气条件下的疲劳寿命。利用扫描电镜对试样断口进行了观察和分析，并对疲劳寿命提高机制进行了讨论。
K417镍基高温合金是我国广泛应用于制造航空发动机涡轮叶片的材料。研究了采用喷丸再结晶方法提高K417合金疲劳寿命的可行性。实验结果表明，该方法可以有效提高K417合金在650℃大气条件下的疲劳寿命。利用扫描电镜对试样断口进行了观察和分析，并对疲劳寿命提高机制进行了讨论。
2006, 35(8):1299-1302.
Abstract:
The effects of sintering atmospheres(vacuum,N2,Ar)on the chemical composition,saturation intensity and coercive force were studied by using X-ray diffraction,electrons back scattered images,Co-% magnetism meter and coercive force meter for the Ti(CN)base ceramets.The test results indicated that the total amount of the C,N,O and the saturation intensity were increased,but the lattice constant of binder phase was decreased in the corresponding alloy after the green compacts of Ti(CN)base ceramets were sintered in Ar,vacuum,N2,respectively.It caused a non-uniform construction if sintering in Ar and N2;even more influence in N2,resulting in a disorder coercive force.The values of Co-% magnetism and coercive force could be used as a criterion of the change of chemical composition and structure.
The effects of sintering atmospheres(vacuum,N2,Ar)on the chemical composition,saturation intensity and coercive force were studied by using X-ray diffraction,electrons back scattered images,Co-% magnetism meter and coercive force meter for the Ti(CN)base ceramets.The test results indicated that the total amount of the C,N,O and the saturation intensity were increased,but the lattice constant of binder phase was decreased in the corresponding alloy after the green compacts of Ti(CN)base ceramets were sintered in Ar,vacuum,N2,respectively.It caused a non-uniform construction if sintering in Ar and N2;even more influence in N2,resulting in a disorder coercive force.The values of Co-% magnetism and coercive force could be used as a criterion of the change of chemical composition and structure.
2006, 35(8):1303-1307.
Abstract:
The amorphous Mg2Ni0.95Sn0.05 + x wt% Ni(x=25,50,75,100,125)composites were synthesized by mechanical ball-milled.The microstructure and electrochemical properties of the composites were investigated.The microstructure analysis indicates that it is difficult to form amorphous structure when the Mg2Ni0.95Sn0.05 alloy is ball-milled without addition of Ni powder.The addition of Ni does favor the formation of amorphous structure.The electrochemical analysis indicates that the discharge capacity of as-cast Mg2Ni0.95Sn0.05 alloy is only 16 mAh/g and almost has no changes after 100 h ball milling.When the alloy with addition of Ni powder was milled its discharge capacity was greatly increased.With increasing of Ni content x,the discharge capacity increased first and then decreased,and reached the maximum of 625.6 mAh/g at x=75.For x=50 composite,the discharge capacity increased after increasing of the ball-milling time,and the maximal discharge capacity increased to 670 mAh/g at t=200 h.
The amorphous Mg2Ni0.95Sn0.05 + x wt% Ni(x=25,50,75,100,125)composites were synthesized by mechanical ball-milled.The microstructure and electrochemical properties of the composites were investigated.The microstructure analysis indicates that it is difficult to form amorphous structure when the Mg2Ni0.95Sn0.05 alloy is ball-milled without addition of Ni powder.The addition of Ni does favor the formation of amorphous structure.The electrochemical analysis indicates that the discharge capacity of as-cast Mg2Ni0.95Sn0.05 alloy is only 16 mAh/g and almost has no changes after 100 h ball milling.When the alloy with addition of Ni powder was milled its discharge capacity was greatly increased.With increasing of Ni content x,the discharge capacity increased first and then decreased,and reached the maximum of 625.6 mAh/g at x=75.For x=50 composite,the discharge capacity increased after increasing of the ball-milling time,and the maximal discharge capacity increased to 670 mAh/g at t=200 h.
2006, 35(8):1308-1310.
Abstract:
The MoS2/Ti composite films were deposited on SKD-11 steel and Si wafer by D.C, magnetron sputtering. The titanium content of the films increases with the Ti target current increasing according to EPMA. The FE-SEM result confirms that the film morphology is composed of the columns with the size of nano-meter, and more compact and hard at a higher Ti target current.
The MoS2/Ti composite films were deposited on SKD-11 steel and Si wafer by D.C, magnetron sputtering. The titanium content of the films increases with the Ti target current increasing according to EPMA. The FE-SEM result confirms that the film morphology is composed of the columns with the size of nano-meter, and more compact and hard at a higher Ti target current.
2006, 35(8):1311-1314.
Abstract:
初步研究了磁致伸缩材料TbFe1.9合金在磁场中凝固的取向控制。结果表明，在与重力平行的120mT磁场中，当Ф16mm的合金熔体的冷却速率为0．7℃／min时，平行于磁场的[111]取向将成为凝固后试样中的择优取向。结合对凝固速率的控制，在远高于居里点的高温熔体中，磁性材料的晶体生长沿易轴的取向可在较弱的磁场中实现。
初步研究了磁致伸缩材料TbFe1.9合金在磁场中凝固的取向控制。结果表明，在与重力平行的120mT磁场中，当Ф16mm的合金熔体的冷却速率为0．7℃／min时，平行于磁场的[111]取向将成为凝固后试样中的择优取向。结合对凝固速率的控制，在远高于居里点的高温熔体中，磁性材料的晶体生长沿易轴的取向可在较弱的磁场中实现。
2006, 35(8):1315-1318.
Abstract:
为了揭示高合金化难变形GH742高温合金铸锭偏析规律及随后均匀化处理过程中元素分布规律，采用微观组织分析手段分析研究了该合金铸态和均匀化态的显微组织和元素的偏析情况：根据实验中偏析元素Nb，Ti的分布，讨论了偏析指数与工艺参数和材料参数的关系。研究结果认为：偏析指数的变化量舶在枝晶间距为80μm～120μm时减小量最大，并且在枝晶间距为120μm的条件下，合金在1160℃退火8h和16h的Nb元素的占计算值与实验值较符合。
为了揭示高合金化难变形GH742高温合金铸锭偏析规律及随后均匀化处理过程中元素分布规律，采用微观组织分析手段分析研究了该合金铸态和均匀化态的显微组织和元素的偏析情况：根据实验中偏析元素Nb，Ti的分布，讨论了偏析指数与工艺参数和材料参数的关系。研究结果认为：偏析指数的变化量舶在枝晶间距为80μm～120μm时减小量最大，并且在枝晶间距为120μm的条件下，合金在1160℃退火8h和16h的Nb元素的占计算值与实验值较符合。
2006, 35(8):1319-1322.
Abstract:
The effects of soft-contact electromagnetic casting(EMC)on the phase constitution,microstructure,mechanical property,and corrosion resistance of AZ61 magnesium alloy were investigated by comparing with the die cast ingot.Results show that the ingots made by different methods have the same phase constitution.The soft-contact EMC ingots have more fine and uniform grain structure,which improves the mechanical property of magnesium alloys.The ultimate tensile strength and elongation of soft-contact EMC specimens increase by about 30% and 27%,respectively.Moreover the fracture morphologies of soft-contact EMC specimens have more characters of gliding fracture.The potentiodynamic polarization indicates that the soft-contact EMC ingots have much better corrosion resisting property than the die cast ones because the better microstructure of soft-contact EMC improves the corrosion potential and decreases the corrosion current density.
The effects of soft-contact electromagnetic casting(EMC)on the phase constitution,microstructure,mechanical property,and corrosion resistance of AZ61 magnesium alloy were investigated by comparing with the die cast ingot.Results show that the ingots made by different methods have the same phase constitution.The soft-contact EMC ingots have more fine and uniform grain structure,which improves the mechanical property of magnesium alloys.The ultimate tensile strength and elongation of soft-contact EMC specimens increase by about 30% and 27%,respectively.Moreover the fracture morphologies of soft-contact EMC specimens have more characters of gliding fracture.The potentiodynamic polarization indicates that the soft-contact EMC ingots have much better corrosion resisting property than the die cast ones because the better microstructure of soft-contact EMC improves the corrosion potential and decreases the corrosion current density.
2006, 35(8):1323-1326.
Abstract:
以高温合金DD3为基材，利用电镀工艺得到10μm的Pd镀层，然后在1050℃分别做4h和14h真空热处理，以研究Pd镀层的阻扩散行为。XRD和SEM／EDS的分析结果表明，电镀后的DD3表面得到的是单一的Pd镀层，但经过1050℃，4h和14h的真空热处理之后，基体中的元素如Al，Cr，Co和Ni等会通过Pd镀层扩散到表面，说明Pd镀层本身不能作为阻止基体元素扩散的涂层用于DD3的基体之上。
以高温合金DD3为基材，利用电镀工艺得到10μm的Pd镀层，然后在1050℃分别做4h和14h真空热处理，以研究Pd镀层的阻扩散行为。XRD和SEM／EDS的分析结果表明，电镀后的DD3表面得到的是单一的Pd镀层，但经过1050℃，4h和14h的真空热处理之后，基体中的元素如Al，Cr，Co和Ni等会通过Pd镀层扩散到表面，说明Pd镀层本身不能作为阻止基体元素扩散的涂层用于DD3的基体之上。
2006, 35(8):1327-1330.
Abstract:
Three specifications of the three-way catalysts(TWC)were prepared using an excellent Ceria-Zirconia solid solutions as oxygen storage materials to match the three vehicles made in China reaching the Eu III standard.The catalysts activities before or after aging for 100 hours were researched on the engine bench test system.The three vehicles matched with the fresh catalysts and the aging catalysts reached the Eu III standard for the Type 1 test and 80 000 kilometers durability.
Three specifications of the three-way catalysts(TWC)were prepared using an excellent Ceria-Zirconia solid solutions as oxygen storage materials to match the three vehicles made in China reaching the Eu III standard.The catalysts activities before or after aging for 100 hours were researched on the engine bench test system.The three vehicles matched with the fresh catalysts and the aging catalysts reached the Eu III standard for the Type 1 test and 80 000 kilometers durability.
2006, 35(8):1331-1333.
Abstract:
采用顶部籽晶提拉法(TSSG)从助溶剂K2W2O7中生长出尺寸为25 mm×21 mm×18 mm的YbKY(WO4)2激光晶体.对原料进行了预烧,有效地抑制了原料的挥发.采用XRD,热重-差热分析(TG-DTA)及红外光谱对样品进行了表征.实验表明所生长的晶体为β-YbKYW.用偏光显微镜对晶体生长条纹、生长丘、生长台阶和包裹物等缺陷进行了观察,认为它们形成的原因是晶体生长工艺不稳定,温度梯度过大,拉速和降温速率过快等.
采用顶部籽晶提拉法(TSSG)从助溶剂K2W2O7中生长出尺寸为25 mm×21 mm×18 mm的YbKY(WO4)2激光晶体.对原料进行了预烧,有效地抑制了原料的挥发.采用XRD,热重-差热分析(TG-DTA)及红外光谱对样品进行了表征.实验表明所生长的晶体为β-YbKYW.用偏光显微镜对晶体生长条纹、生长丘、生长台阶和包裹物等缺陷进行了观察,认为它们形成的原因是晶体生长工艺不稳定,温度梯度过大,拉速和降温速率过快等.
2006, 35(8):1334-1337.
Abstract:
应用sol-gel法成功地合成了超细SrFe12O19磁粉。研究了Sr^2＋与Fe^3＋离子比、醇水比、预热处理温度和升温速率对粉体的形成及其性能的影响。XRD分析表明磁粉形成了单相的锶铁氧体粉体；生成单相SrFe12O19粉体的Sr^2＋与Fe^3＋的离子摩尔比为1．13：12．00；粒子尺寸为43．2nm～51．8nm，接近理论单畴尺寸，使粉体有较高的矫顽力。低温预处理、较高的醇水比和300℃-900℃之间较快的升温速率导致了粒子结晶度和沿易磁化c-轴取向晶化的显著增大，这又增大了粉体的饱和磁化强度。
应用sol-gel法成功地合成了超细SrFe12O19磁粉。研究了Sr^2＋与Fe^3＋离子比、醇水比、预热处理温度和升温速率对粉体的形成及其性能的影响。XRD分析表明磁粉形成了单相的锶铁氧体粉体；生成单相SrFe12O19粉体的Sr^2＋与Fe^3＋的离子摩尔比为1．13：12．00；粒子尺寸为43．2nm～51．8nm，接近理论单畴尺寸，使粉体有较高的矫顽力。低温预处理、较高的醇水比和300℃-900℃之间较快的升温速率导致了粒子结晶度和沿易磁化c-轴取向晶化的显著增大，这又增大了粉体的饱和磁化强度。
2006, 35(8):1338-1340.
Abstract:
Several binary silver alloys, including AgSb, AgTb, AgDy, AgGa, AgTi and AgAl, have been investigated in order to develop new sheath alloys used for the BSCCO tapes. The mechanical properties of these alloys have been measured, including the tensile strength and strain. The results show that the Ag-Sb and Ag-Ti samples are the best candidate materials among the six alloys and have the highest strain and the highest tensile strength, respectively. The AgTb and AgDy alloys also have good properties while AgGa and AgAl alloys can not be used as sheathed materials due to their lower strains.
Several binary silver alloys, including AgSb, AgTb, AgDy, AgGa, AgTi and AgAl, have been investigated in order to develop new sheath alloys used for the BSCCO tapes. The mechanical properties of these alloys have been measured, including the tensile strength and strain. The results show that the Ag-Sb and Ag-Ti samples are the best candidate materials among the six alloys and have the highest strain and the highest tensile strength, respectively. The AgTb and AgDy alloys also have good properties while AgGa and AgAl alloys can not be used as sheathed materials due to their lower strains.
2006, 35(8):1341-1344.
Abstract:
室温下在二甲基亚砜（DMSO）溶液中利用电解技术制备了具有金属光泽的分散La-Co及La-Co-Ni非晶态合金粉末。合金粉末颗粒尺寸在0．1gm～20gm范围内。La-Co合金粉末随着电解液中LaCl3和CoCl2浓度的变化，其La与Co的原子比由5：1变为1：5；La-Co-Ni合金粉末随着电解液中LaCl3浓度的增加，其La的含量由5．57％（质量分数）增加到15．28％。因此，可以通过控制电解液浓度比的方法来调节合金粉末中各金属的含量。对合金粉末压片样品进行线性扫描循环伏安试验研究，得出La-Co合金粉末中La^3＋，Co^2＋的还原峰电位分别为2．68V，-1．83V；La，Co的氧化峰电位为-1．10V，-0.42V。La-Co-Ni合金粉末中Ni^2＋，Co^2＋共还原电位在-1．49V～-1．70V范围，Ni，Co的共氧化电位在-0.65V～0.51V范围。
室温下在二甲基亚砜（DMSO）溶液中利用电解技术制备了具有金属光泽的分散La-Co及La-Co-Ni非晶态合金粉末。合金粉末颗粒尺寸在0．1gm～20gm范围内。La-Co合金粉末随着电解液中LaCl3和CoCl2浓度的变化，其La与Co的原子比由5：1变为1：5；La-Co-Ni合金粉末随着电解液中LaCl3浓度的增加，其La的含量由5．57％（质量分数）增加到15．28％。因此，可以通过控制电解液浓度比的方法来调节合金粉末中各金属的含量。对合金粉末压片样品进行线性扫描循环伏安试验研究，得出La-Co合金粉末中La^3＋，Co^2＋的还原峰电位分别为2．68V，-1．83V；La，Co的氧化峰电位为-1．10V，-0.42V。La-Co-Ni合金粉末中Ni^2＋，Co^2＋共还原电位在-1．49V～-1．70V范围，Ni，Co的共氧化电位在-0.65V～0.51V范围。
