Volume 35,Issue 10,2006 Table of Contents
2006, 35(10):1513-1515.
Abstract:
This summarized thesis has begun to be written every year since 1996. In this paper it consists of (1) magneto-optic recording and magnetic recording material; (2) nano-ferrite material; (3) new magnetic measuring device; (4) magneto-resistive material; (5) rare-earth magnetic material.
This summarized thesis has begun to be written every year since 1996. In this paper it consists of (1) magneto-optic recording and magnetic recording material; (2) nano-ferrite material; (3) new magnetic measuring device; (4) magneto-resistive material; (5) rare-earth magnetic material.
2006, 35(10):1516-1521.
Abstract:
The interfacial reaction of Ti-6Al-4V composites reinforced with Chinese SiC fiber was investigated by means of scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The reaction product of TiC with fine grains and large grains was identified between the Ti-6Al-4V matrix and the C-coating of the SiC fiber. However, in the interfacial reaction zone of the SiCf /Ti-6Al-4V composite in which the SiC fiber has no C-coating, from SiC fiber to Ti-6Al-4V matrix, there exist fine grains of TiC+Ti5Si3, large grains of TiC and Ti3SiC2. The thickness of the interfacial reaction zone was measured and the interfacial reaction mechanism was discussed.
The interfacial reaction of Ti-6Al-4V composites reinforced with Chinese SiC fiber was investigated by means of scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The reaction product of TiC with fine grains and large grains was identified between the Ti-6Al-4V matrix and the C-coating of the SiC fiber. However, in the interfacial reaction zone of the SiCf /Ti-6Al-4V composite in which the SiC fiber has no C-coating, from SiC fiber to Ti-6Al-4V matrix, there exist fine grains of TiC+Ti5Si3, large grains of TiC and Ti3SiC2. The thickness of the interfacial reaction zone was measured and the interfacial reaction mechanism was discussed.
2006, 35(10):1522-1525.
Abstract:
通过快速冷冻沉淀法制备非晶态氢氧化镍粉体，微粒形状不规则，具有较小粒度分布和较大比表面积。经测量，发现其样品粉体拉曼光谱（Raman）峰较多，差热分析（DSC）发现其分解温度较低，为295．18℃，结果分析表明活性较高。将所制备的非晶态Ni（OH）2粉体作为活性物质合成正极材料，并组装成MH—Ni碱性模拟电池，在恒流50mA／g下充电8h，25mA／g下放电，终止电压为1．0V时，其放电工作电压平稳且时间长，放电平台为1．26v。放电比容量可达333．22mAh／g，高于β-Ni（OH）2的理论比容量289mAh／g，循环伏安曲线的测试结果表明，可逆性能较好，在碱性电解液中结构稳定。
通过快速冷冻沉淀法制备非晶态氢氧化镍粉体，微粒形状不规则，具有较小粒度分布和较大比表面积。经测量，发现其样品粉体拉曼光谱（Raman）峰较多，差热分析（DSC）发现其分解温度较低，为295．18℃，结果分析表明活性较高。将所制备的非晶态Ni（OH）2粉体作为活性物质合成正极材料，并组装成MH—Ni碱性模拟电池，在恒流50mA／g下充电8h，25mA／g下放电，终止电压为1．0V时，其放电工作电压平稳且时间长，放电平台为1．26v。放电比容量可达333．22mAh／g，高于β-Ni（OH）2的理论比容量289mAh／g，循环伏安曲线的测试结果表明，可逆性能较好，在碱性电解液中结构稳定。
4 Some Material Science Questions in Growing YBCO Quasi-Single Crystals by the Powder Melting Process
2006, 35(10):1526-1530.
Abstract:
Several material science questions involved with growing YBCO quasi-single crystals by the powder melting process (PMP), including the formation of the liquid phase, crystal preferential growth and its controlling, peritectic reaction mechanism and the stability of the front growing interface, size distribution of 211 particles and the formation and controlling of relative defects have been introduced and discussed in the present paper.
Several material science questions involved with growing YBCO quasi-single crystals by the powder melting process (PMP), including the formation of the liquid phase, crystal preferential growth and its controlling, peritectic reaction mechanism and the stability of the front growing interface, size distribution of 211 particles and the formation and controlling of relative defects have been introduced and discussed in the present paper.
2006, 35(10):1531-1534.
Abstract:
采用顶部籽晶提拉法(TSSG)生长出Nd3+:KGd(WO4)2晶体,测得Nd3+实际掺杂浓度3.2at%。测得样品的吸收光谱及荧光光谱,计算得出808nm处吸收截面为0.6799×10-20cm2;荧光输出波长为1068nm和1351nm,测得荧光寿命为112μs。对不同尺寸的两样品进行了激光实验,当LD泵浦源输出功率为900mW时,分别获得326mW,305mW的1064nm激光输出,斜效率分别为62.7%和57.8%。水平和垂直两个方向上光束传输因子M2均小于1.2。经倍频获得532nm的绿光。用Cr:LuAG作为可饱和吸收体进行调Q实验,重复频率为15kHz时,脉冲宽为170ns。
采用顶部籽晶提拉法(TSSG)生长出Nd3+:KGd(WO4)2晶体,测得Nd3+实际掺杂浓度3.2at%。测得样品的吸收光谱及荧光光谱,计算得出808nm处吸收截面为0.6799×10-20cm2;荧光输出波长为1068nm和1351nm,测得荧光寿命为112μs。对不同尺寸的两样品进行了激光实验,当LD泵浦源输出功率为900mW时,分别获得326mW,305mW的1064nm激光输出,斜效率分别为62.7%和57.8%。水平和垂直两个方向上光束传输因子M2均小于1.2。经倍频获得532nm的绿光。用Cr:LuAG作为可饱和吸收体进行调Q实验,重复频率为15kHz时,脉冲宽为170ns。
6 Effects of Annealing Temperature on Laves Phase Cr2Nb Synthesizing by Solid Phase Thermal Reaction
2006, 35(10):1535-1538.
Abstract:
Using Cr-Nb MA powders ball milled for 30 h then annealed for 3 h, the effects of annealing temperature on Laves phase Cr2Nb synthesizing by solid phase thermal reaction have been investigated. The lowest annealing temperature of the powder for full synthesizing of Laves phase Cr2Nb was obtained. The optimized low temperature annealing parameters for Laves phase Cr2Nb synthesizing by solid phase thermal reaction can theoretically provide guidance for preparing both high strength and high tough Cr2Nb alloy or Cr2Nb-based composite with micro- / nano-grains by a process of mechanical alloying followed by a hot pressing or sintering.
Using Cr-Nb MA powders ball milled for 30 h then annealed for 3 h, the effects of annealing temperature on Laves phase Cr2Nb synthesizing by solid phase thermal reaction have been investigated. The lowest annealing temperature of the powder for full synthesizing of Laves phase Cr2Nb was obtained. The optimized low temperature annealing parameters for Laves phase Cr2Nb synthesizing by solid phase thermal reaction can theoretically provide guidance for preparing both high strength and high tough Cr2Nb alloy or Cr2Nb-based composite with micro- / nano-grains by a process of mechanical alloying followed by a hot pressing or sintering.
2006, 35(10):1539-1543.
Abstract:
研究了固溶-时效处理工艺和固溶-预冷变形-时效处理工艺对Cu-Co-Cr-Si合金力学性能、电学性能及其显微组织结构的影响。结果表明，最佳形变热处理工艺为980℃固溶1h，冰盐水淬火，40％预冷变形之后480℃时效4h。合金的抗拉强度、屈服强度、延伸率、硬度和相对电导率分别达到634MPa，575MPa，8．9％，1700MPa（HB）和43．2％IACS。这种合金有显著的时效强化特性，强化相为Cr粒子、Cr3Co5Si2相和Co2Si相。合金的高强度来源于固溶强化、亚结构强化和第二相析出强化。
研究了固溶-时效处理工艺和固溶-预冷变形-时效处理工艺对Cu-Co-Cr-Si合金力学性能、电学性能及其显微组织结构的影响。结果表明，最佳形变热处理工艺为980℃固溶1h，冰盐水淬火，40％预冷变形之后480℃时效4h。合金的抗拉强度、屈服强度、延伸率、硬度和相对电导率分别达到634MPa，575MPa，8．9％，1700MPa（HB）和43．2％IACS。这种合金有显著的时效强化特性，强化相为Cr粒子、Cr3Co5Si2相和Co2Si相。合金的高强度来源于固溶强化、亚结构强化和第二相析出强化。
2006, 35(10):1544-1547.
Abstract:
用化学腐蚀法、金相显微观察、透射电镜（TEM）、电子探针X射线微区分析（EPMA）和扫描电镜能谱分析（EDX）等手段，对φ76mm非掺杂（ND）半绝缘砷化镓（SI-GaAs）单晶中微缺陷、碳的微区分布进行了分析。结果表明：在晶体周边区域，由高密度位错运动和反应形成胞状结构，该胞状结构的本质就是晶体结晶时形成的小角度晶界，且位错与微缺陷有强烈的相互作用：杂质碳在胞壁、近胞壁和完整区的含量依次降低，存在条纹分布。
用化学腐蚀法、金相显微观察、透射电镜（TEM）、电子探针X射线微区分析（EPMA）和扫描电镜能谱分析（EDX）等手段，对φ76mm非掺杂（ND）半绝缘砷化镓（SI-GaAs）单晶中微缺陷、碳的微区分布进行了分析。结果表明：在晶体周边区域，由高密度位错运动和反应形成胞状结构，该胞状结构的本质就是晶体结晶时形成的小角度晶界，且位错与微缺陷有强烈的相互作用：杂质碳在胞壁、近胞壁和完整区的含量依次降低，存在条纹分布。
2006, 35(10):1548-1553.
Abstract:
According to the expression of strain energy release ratio, a triaxiality factor, an expanding factor from isotropic material to orthotropic materials, for single crystal superalloy that contains three elastic constants was defined. By using the triaxiality factor to modify strain range as a failure parameter, effects of crystallographic orientation and multiaxial loading on fatigue life can be eliminated remarkably. Applying strain energy release ratio to describe fatigue damage course of orthotropic materials and taking account of nonlinear effect of crystal anisotropy of single crystal superalloys versus fatigue damage and alternate changing characteristic of cyclic loads by introducing an orientation function and a cyclic characteristic parameter for damage force, a low cycle fatigue damage model for single crystal superalloy was proposed. The low cycle fatigue test data correlation to DD3 and CMSX-2 single crystal superalloy with the parameter by using multivariate linear regression analysis is good and the all test data fall into the factor of 2.0 and 2.5 scatter band, respectively.
According to the expression of strain energy release ratio, a triaxiality factor, an expanding factor from isotropic material to orthotropic materials, for single crystal superalloy that contains three elastic constants was defined. By using the triaxiality factor to modify strain range as a failure parameter, effects of crystallographic orientation and multiaxial loading on fatigue life can be eliminated remarkably. Applying strain energy release ratio to describe fatigue damage course of orthotropic materials and taking account of nonlinear effect of crystal anisotropy of single crystal superalloys versus fatigue damage and alternate changing characteristic of cyclic loads by introducing an orientation function and a cyclic characteristic parameter for damage force, a low cycle fatigue damage model for single crystal superalloy was proposed. The low cycle fatigue test data correlation to DD3 and CMSX-2 single crystal superalloy with the parameter by using multivariate linear regression analysis is good and the all test data fall into the factor of 2.0 and 2.5 scatter band, respectively.
2006, 35(10):1554-1556.
Abstract:
采用一种制备掺杂纳米VO2粉体的新方法获得掺Mo纳米V02粉体。用XRD，TEM，XPS手段对掺杂纳米VO2的结构进行了表征，并研究了掺杂V02的相变特性。结果表明，所制备的纳米VO2的尺寸约为26nm，形貌呈近球形。掺入的Mo以Mo^＋6的形式存在于VO2的晶格中，形成V1-x，MoxO2固溶体。掺杂纳米VO2粉体的电阻随温度的变化具有明显的开关特性。随掺入Mo含量的增加，VO2的相变温度呈线性下降，在6％MoO3的掺入量时，相变温度降为45℃。
采用一种制备掺杂纳米VO2粉体的新方法获得掺Mo纳米V02粉体。用XRD，TEM，XPS手段对掺杂纳米VO2的结构进行了表征，并研究了掺杂V02的相变特性。结果表明，所制备的纳米VO2的尺寸约为26nm，形貌呈近球形。掺入的Mo以Mo^＋6的形式存在于VO2的晶格中，形成V1-x，MoxO2固溶体。掺杂纳米VO2粉体的电阻随温度的变化具有明显的开关特性。随掺入Mo含量的增加，VO2的相变温度呈线性下降，在6％MoO3的掺入量时，相变温度降为45℃。
2006, 35(10):1557-1559.
Abstract:
Double hexagonal-close-packed (dhcp) crystal structure is a variant of hexagonal-close-packed (hcp). It is always found in phase transformation process at extreme conditions, i. e., high temperature and pressure. In this paper, structural factor of the dhcp was calculated on basis of the electron diffraction theory and the forbidden reflection law was discussed. If l is odd or the condition, 2h+k=3n, l=4n+2 (n a random integer.), is met, the crystal plane (hkl) will be forbidden to reflect. This predicted result is good agreement with the diffraction patterns from an investigation of phase transformations in commercial magnesium alloy.
Double hexagonal-close-packed (dhcp) crystal structure is a variant of hexagonal-close-packed (hcp). It is always found in phase transformation process at extreme conditions, i. e., high temperature and pressure. In this paper, structural factor of the dhcp was calculated on basis of the electron diffraction theory and the forbidden reflection law was discussed. If l is odd or the condition, 2h+k=3n, l=4n+2 (n a random integer.), is met, the crystal plane (hkl) will be forbidden to reflect. This predicted result is good agreement with the diffraction patterns from an investigation of phase transformations in commercial magnesium alloy.
2006, 35(10):1560-1563.
Abstract:
研究了^7LiH试样在不同温度下的拉伸性能，并对试样断口进行了分析。结果表明，无论是否经过烧结，^7LiH试样的抗拉强度在100℃～300℃的温度范围，随试验温度的升高而增加。在300℃～600℃的温度范围，随试验温度升高而降低，并且烧结坯^7LiH试样的抗拉强度明显高于冷压坯。冷压坯^7LiH试样经过从350℃-650℃的温度范围烧结后，在530℃烧结^7LiH试样的室温抗拉强度达到最大值。
研究了^7LiH试样在不同温度下的拉伸性能，并对试样断口进行了分析。结果表明，无论是否经过烧结，^7LiH试样的抗拉强度在100℃～300℃的温度范围，随试验温度的升高而增加。在300℃～600℃的温度范围，随试验温度升高而降低，并且烧结坯^7LiH试样的抗拉强度明显高于冷压坯。冷压坯^7LiH试样经过从350℃-650℃的温度范围烧结后，在530℃烧结^7LiH试样的室温抗拉强度达到最大值。
2006, 35(10):1564-1567.
Abstract:
断口表面的分形维数是断裂表面粗糙度的一种度量，它和材料的韧性相关。应用小波分解技术，用“双毯法”提取了锆-4合金低周疲劳断口在低频、水平高频、垂直高频、对角高频方向上的分形维数。结果表明锆-4合金低周疲劳断口具有分形特征；分形维数与疲劳寿命有关，疲劳寿命越高，分形维数越大；随着分解级数的增加，不同寿命的断口分维值之间差距加大，小波分解的级数越多，越能获得有效的特征量；同一断口，放大倍数不同，分形维数差异较大。低倍下（≤4000XD），随分解级数增加，对角方向上高频信号变化更复杂，分维值上升较快；高倍下（≥8000XD），断口的复杂性降低。
断口表面的分形维数是断裂表面粗糙度的一种度量，它和材料的韧性相关。应用小波分解技术，用“双毯法”提取了锆-4合金低周疲劳断口在低频、水平高频、垂直高频、对角高频方向上的分形维数。结果表明锆-4合金低周疲劳断口具有分形特征；分形维数与疲劳寿命有关，疲劳寿命越高，分形维数越大；随着分解级数的增加，不同寿命的断口分维值之间差距加大，小波分解的级数越多，越能获得有效的特征量；同一断口，放大倍数不同，分形维数差异较大。低倍下（≤4000XD），随分解级数增加，对角方向上高频信号变化更复杂，分维值上升较快；高倍下（≥8000XD），断口的复杂性降低。
2006, 35(10):1568-1571.
Abstract:
The influence of volume fraction on tungsten fiber/ Zr-based bulk metallic glass matrix composites was studied. The results show that the composites is fractured by shearing when the volume fraction is less than 50%; compressive strength and plastic deformation increase with the increase of volume fraction; when the volume fraction is more than 50%, the composites is fractured by bending and splitting, compressive strength increases continuously, but plastic deformation decreases with the increase of the volume fraction. The analysis indicates that mechanieal properties change with volume fraction of tungsten fiber affected by the form of shear bands.
The influence of volume fraction on tungsten fiber/ Zr-based bulk metallic glass matrix composites was studied. The results show that the composites is fractured by shearing when the volume fraction is less than 50%; compressive strength and plastic deformation increase with the increase of volume fraction; when the volume fraction is more than 50%, the composites is fractured by bending and splitting, compressive strength increases continuously, but plastic deformation decreases with the increase of the volume fraction. The analysis indicates that mechanieal properties change with volume fraction of tungsten fiber affected by the form of shear bands.
2006, 35(10):1572-1576.
Abstract:
The influence of annealing temperature on the structure and electrochemical properties of La1.5Mg0.5Ni7.0 hydrogen storage electrode alloys was studied. XRD and SEM analyses show that the as-cast alloy consists of LaNi5 phase, LaMgNi4 phase, (La, Mg)Ni3 phase and Gd2Co7 type phase. After heat treatment, the alloys consist of Gd2Co7 type phase, Ce2Ni7 type phase and (La, Mg)Ni3 phase, and the (La, Mg)Ni3 phase content decreases and the Ce2Ni7 type phase content increases with increasing of annealing temperature. The unit cell volumes and a-axes of PuNi3 type phase increase with increasing of annealing temperature. The electrochemical studies show that the discharge capacity and cyclic stability of the alloy electrodes have been improved markedly after annealing treatment. The discharge capacity of the alloy annealed at 1073 K is the highest (391.2 mAh/g) and then decreases with increasing of annealing temperature. However, with the increase of annealing temperature, the cyclic stability of the alloy electrode increases and the cycle life of the alloy annealed at 1173 K is the longest (C150/Cmax=82%). In addition, both the as-cast and the annealed alloy electrodes have quite good HRD. The high rate dischargeability (HRD) of the alloy electrodes increases with increasing of annealing temperature and the alloy annealed at 1173 K is the best. The exchange current density (I0), the limit current density (IL) and the hydrogen diffusion coefficient (D) of the alloy electrodes are consistent with the variation of the high rate dischargeability (HRD).
The influence of annealing temperature on the structure and electrochemical properties of La1.5Mg0.5Ni7.0 hydrogen storage electrode alloys was studied. XRD and SEM analyses show that the as-cast alloy consists of LaNi5 phase, LaMgNi4 phase, (La, Mg)Ni3 phase and Gd2Co7 type phase. After heat treatment, the alloys consist of Gd2Co7 type phase, Ce2Ni7 type phase and (La, Mg)Ni3 phase, and the (La, Mg)Ni3 phase content decreases and the Ce2Ni7 type phase content increases with increasing of annealing temperature. The unit cell volumes and a-axes of PuNi3 type phase increase with increasing of annealing temperature. The electrochemical studies show that the discharge capacity and cyclic stability of the alloy electrodes have been improved markedly after annealing treatment. The discharge capacity of the alloy annealed at 1073 K is the highest (391.2 mAh/g) and then decreases with increasing of annealing temperature. However, with the increase of annealing temperature, the cyclic stability of the alloy electrode increases and the cycle life of the alloy annealed at 1173 K is the longest (C150/Cmax=82%). In addition, both the as-cast and the annealed alloy electrodes have quite good HRD. The high rate dischargeability (HRD) of the alloy electrodes increases with increasing of annealing temperature and the alloy annealed at 1173 K is the best. The exchange current density (I0), the limit current density (IL) and the hydrogen diffusion coefficient (D) of the alloy electrodes are consistent with the variation of the high rate dischargeability (HRD).
16 The Effective Diffusion Coefficient and Diffusion Activation Energy of Cd in Cd0.9Zn0.1Te Crystal
2006, 35(10):1577-1580.
Abstract:
为了计算Cd在Cd0.9Zn0.1Te(CZT)晶体中的有效扩散系数DCd与扩散激活能QCd,利用Cd在CZT晶体中的扩散特性,设计了在不同Cd压下对CZT的退火实验,推导出了晶体电阻率与Cd有效扩散系数之间的函数关系,经过计算,首次获得了在1073 K,973 K和873 K温度时Cd原子在CZT晶体中的有效扩散系数DCd,分别为1.464×10-10cm2/s,1.085×10-11cm2/s和4.167×10-13cm2/s.将扩散数据经过拟合后得到了Cd原子在CZT晶片中有效扩散系数的表达式2.33×exp(-2.38 eV/kT)(873 K～1073 K),其中扩散激活能QCd为2.38 eV.
为了计算Cd在Cd0.9Zn0.1Te(CZT)晶体中的有效扩散系数DCd与扩散激活能QCd,利用Cd在CZT晶体中的扩散特性,设计了在不同Cd压下对CZT的退火实验,推导出了晶体电阻率与Cd有效扩散系数之间的函数关系,经过计算,首次获得了在1073 K,973 K和873 K温度时Cd原子在CZT晶体中的有效扩散系数DCd,分别为1.464×10-10cm2/s,1.085×10-11cm2/s和4.167×10-13cm2/s.将扩散数据经过拟合后得到了Cd原子在CZT晶片中有效扩散系数的表达式2.33×exp(-2.38 eV/kT)(873 K～1073 K),其中扩散激活能QCd为2.38 eV.
2006, 35(10):1581-1585.
Abstract:
A thermodynamic calculation and data analysis were carried out for silver tin oxide composite material prepared by reaction synthesis processing using Gibbs Helmholtz equation. The results show that the reactive temperature is below 505 K, the reactive synthesis of silver tin oxide belongs to the substitution reaction of solid-solid. When the reactive temperature is over 505 K, the reactive synthesis of silver tin oxide belongs to the oxidation reaction between oxygen and solid. By the calculation of free energy per unit volume and decomposed oxygen partial pressure of SnO, SnO2 in the rang from 505 K to 1200 K, it can be determined that the final production is Ag phase and SnO2 phase for the oxygen reaction of Ag2O, Ag, Sn. But no SnO phase exists in the material. The analysis of thermodynamics calculation data and oxygen branch-pressure offers an academic foundation for preparing AgSnO2 composite material adopting reaction synthesis processing.
A thermodynamic calculation and data analysis were carried out for silver tin oxide composite material prepared by reaction synthesis processing using Gibbs Helmholtz equation. The results show that the reactive temperature is below 505 K, the reactive synthesis of silver tin oxide belongs to the substitution reaction of solid-solid. When the reactive temperature is over 505 K, the reactive synthesis of silver tin oxide belongs to the oxidation reaction between oxygen and solid. By the calculation of free energy per unit volume and decomposed oxygen partial pressure of SnO, SnO2 in the rang from 505 K to 1200 K, it can be determined that the final production is Ag phase and SnO2 phase for the oxygen reaction of Ag2O, Ag, Sn. But no SnO phase exists in the material. The analysis of thermodynamics calculation data and oxygen branch-pressure offers an academic foundation for preparing AgSnO2 composite material adopting reaction synthesis processing.
2006, 35(10):1586-1588.
Abstract:
A-TIG welding for titanium alloy was carried out to study effect of surface activating flux on welding penetration. Halides(CaF2, ZnF2 and MnCl2), Oxides(SiO2, TiO2 and V2O5) and elemental Te were served as fluxes. It is found that the three kinds of experimental halides can improve welding penetration, especially the welding penetration for MnCl2 reaches two times of that of conventional TIG welding. The three kinds of oxides have little effect on weld forming. Elemental Te can curiously increase welding penetration and decrease weld width. It is believed, arc constriction is the main mechanism of halides improving welding penetration of A-TIG welding for titanium alloy, but not for elemental Te.
A-TIG welding for titanium alloy was carried out to study effect of surface activating flux on welding penetration. Halides(CaF2, ZnF2 and MnCl2), Oxides(SiO2, TiO2 and V2O5) and elemental Te were served as fluxes. It is found that the three kinds of experimental halides can improve welding penetration, especially the welding penetration for MnCl2 reaches two times of that of conventional TIG welding. The three kinds of oxides have little effect on weld forming. Elemental Te can curiously increase welding penetration and decrease weld width. It is believed, arc constriction is the main mechanism of halides improving welding penetration of A-TIG welding for titanium alloy, but not for elemental Te.
2006, 35(10):1593-1596.
Abstract:
研究了xTi-18Mn-（50-x）Cr-32V（z=36，34，32，30，28）合金的吸／放氢性能。结果表明：随Ti／Cr比值的减小，合金的晶格常数和晶胞体积减小，这虽然导致合金的最大吸氢量降低，但是合金的有效放氢量增大，且合金PCT曲线的滞后系数降低。合金（110）面法线方向上晶粒尺度的大小是影响合金放氢平台斜率系数的因素之一。对于32Ti．18Mn．18Cr．32V合金，在273K吸氢、353K放氢的条件下，有效放氢量达到1．72％（质量分数），具有实用价值。
研究了xTi-18Mn-（50-x）Cr-32V（z=36，34，32，30，28）合金的吸／放氢性能。结果表明：随Ti／Cr比值的减小，合金的晶格常数和晶胞体积减小，这虽然导致合金的最大吸氢量降低，但是合金的有效放氢量增大，且合金PCT曲线的滞后系数降低。合金（110）面法线方向上晶粒尺度的大小是影响合金放氢平台斜率系数的因素之一。对于32Ti．18Mn．18Cr．32V合金，在273K吸氢、353K放氢的条件下，有效放氢量达到1．72％（质量分数），具有实用价值。
2006, 35(10):1597-1601.
Abstract:
利用小线圈法在多功能冷坩埚电磁约束定向凝固装置上，空载测试了矩形冷坩埚内部空间磁场的大小和分布，考察了开缝数目和开缝长度变化对磁场分布的影响。结果表明：增加坩埚开缝数目可以提高坩埚透磁性，增大磁场强度，减少由于开缝引起的磁场沿边周分布的不均匀性，从而提高铸件质量；缝长增大，磁场沿圆周方向分布的均匀性变差，最大磁场强度向缝长增大的方向偏移，同时感应加热形成的熔区增大。
利用小线圈法在多功能冷坩埚电磁约束定向凝固装置上，空载测试了矩形冷坩埚内部空间磁场的大小和分布，考察了开缝数目和开缝长度变化对磁场分布的影响。结果表明：增加坩埚开缝数目可以提高坩埚透磁性，增大磁场强度，减少由于开缝引起的磁场沿边周分布的不均匀性，从而提高铸件质量；缝长增大，磁场沿圆周方向分布的均匀性变差，最大磁场强度向缝长增大的方向偏移，同时感应加热形成的熔区增大。
2006, 35(10):1602-1604.
Abstract:
对自蔓延高温合成法制备的MgB2进行氩气保护下的烧结实验。通过X射线衍射、扫描电镜和EDX成分分析等方法，发现MgB2在流动氩气保护下于1050℃烧结后部分转化为MgB4。随着烧结温度提高，MgB4生成量增多。生成的MgB4晶粒形貌与MgB2的明显不同。
对自蔓延高温合成法制备的MgB2进行氩气保护下的烧结实验。通过X射线衍射、扫描电镜和EDX成分分析等方法，发现MgB2在流动氩气保护下于1050℃烧结后部分转化为MgB4。随着烧结温度提高，MgB4生成量增多。生成的MgB4晶粒形貌与MgB2的明显不同。
2006, 35(10):1605-1609.
Abstract:
Acid-proof Ti based-MO2 anodes with SnO2+Sb2O4 intermediate layer were prepared by thermal decomposition method, the surface characterization of the electrodes were studied by scanning electron microscopy (SEM), elements composition and valence state of SnO2+Sb2O4 intermediate layers were analyzed with X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS), respectively. The polarization curves of oxygen evolution and high density (4 A/cm2) lifetime of Ti/SnO2+ Sb2O4/MnO2 and Ti/ SnO2+Sb2O4/PbO2 anodes were determined in 1.0 mol/L H2SO4 solution. Their potentials of initial oxygen evolution were lower than those of moble metals, and their lifetimes reached 18 h and 86 h, respectively. The experiment showed that the combination of SnO2+Sb2O4 is a better intermediate layer material and will play a important role in Ti/MnO2 and Ti/PbO2 anodes.
Acid-proof Ti based-MO2 anodes with SnO2+Sb2O4 intermediate layer were prepared by thermal decomposition method, the surface characterization of the electrodes were studied by scanning electron microscopy (SEM), elements composition and valence state of SnO2+Sb2O4 intermediate layers were analyzed with X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS), respectively. The polarization curves of oxygen evolution and high density (4 A/cm2) lifetime of Ti/SnO2+ Sb2O4/MnO2 and Ti/ SnO2+Sb2O4/PbO2 anodes were determined in 1.0 mol/L H2SO4 solution. Their potentials of initial oxygen evolution were lower than those of moble metals, and their lifetimes reached 18 h and 86 h, respectively. The experiment showed that the combination of SnO2+Sb2O4 is a better intermediate layer material and will play a important role in Ti/MnO2 and Ti/PbO2 anodes.
2006, 35(10):1610-1615.
Abstract:
The equivalent circuit model of the metal oxide anodes used in seawater electrolysis can be described by LRs (QdlRct) (QfRf). The L shows the complex microstructure of the electrode. The (QdlRct) describes the electrochemical behavior of the electrode/solution. The (QfRf) the physical impedance of the Ti-support/active oxide coating. Qdl and Rct do not change sharply in de-active region, but Qf and Rf change abruptly in this region. There are still some active components existing in the surface of the anode. The main reason for the deactivation of the anode is the formation of TiO2 between Ti base and the active coating. The dissolution of the active components and the mechanical lose are not the main reasons for the deactivation of the anodes, but they accelerate the formation of TiO2.
The equivalent circuit model of the metal oxide anodes used in seawater electrolysis can be described by LRs (QdlRct) (QfRf). The L shows the complex microstructure of the electrode. The (QdlRct) describes the electrochemical behavior of the electrode/solution. The (QfRf) the physical impedance of the Ti-support/active oxide coating. Qdl and Rct do not change sharply in de-active region, but Qf and Rf change abruptly in this region. There are still some active components existing in the surface of the anode. The main reason for the deactivation of the anode is the formation of TiO2 between Ti base and the active coating. The dissolution of the active components and the mechanical lose are not the main reasons for the deactivation of the anodes, but they accelerate the formation of TiO2.
2006, 35(10):1616-1619.
Abstract:
研究了Y2O3,LiO2,CaO烧结助剂对AlN陶瓷常压烧结致密度和性能的影响。结果发现,同时添加Y2O3,LiO2,CaO作为助剂,在1600℃低温烧结就能获得具有高致密度、较小的晶粒尺寸(1μm~4μm)、较高的抗弯强度(331MPa)、断裂韧性(3.8MPa·m1/2)及导热率(118W·m-1·K-1)的AlN陶瓷。
研究了Y2O3,LiO2,CaO烧结助剂对AlN陶瓷常压烧结致密度和性能的影响。结果发现,同时添加Y2O3,LiO2,CaO作为助剂,在1600℃低温烧结就能获得具有高致密度、较小的晶粒尺寸(1μm~4μm)、较高的抗弯强度(331MPa)、断裂韧性(3.8MPa·m1/2)及导热率(118W·m-1·K-1)的AlN陶瓷。
2006, 35(10):1620-1624.
Abstract:
研究了铸造A356-T6铝合金板不同位置处的拉伸性能。采用扫描电子显微镜和光学显微镜对拉伸断口及断口纵剖面的组织形貌进行了观察分析。试验结果表明，铸造A356-T6铝合金的拉伸屈服强度随离浇道口平面距离的增加而减小，断裂强度则是先减小然后再增大，而延伸率随高度变化不明显。铸造A356-T6铝合金的平均屈服强度、断裂强度、延伸率和断面收缩率分别为216．64MPa，224MPa，1．086％和0．194％。断口分析表明拉伸断口的表面分布着杂质、孔洞、铸造缩孔和氧化膜等缺陷，断口表面也存在开裂的由碳、氧、铁、镁、铝和硅元素形成的复合粒子。铸造A356-T6铝合金在拉伸过程中，裂纹萌生于共晶硅粒子与基体结合处，并沿枝晶胞之间的共晶区域进行扩展，当前进的裂纹遇到取向不一致的共晶硅粒子时，裂纹将截断共晶硅粒子。铸造A356-T6铝合金拉伸断裂方式为沿胞（即穿晶）断裂的准解理断。
研究了铸造A356-T6铝合金板不同位置处的拉伸性能。采用扫描电子显微镜和光学显微镜对拉伸断口及断口纵剖面的组织形貌进行了观察分析。试验结果表明，铸造A356-T6铝合金的拉伸屈服强度随离浇道口平面距离的增加而减小，断裂强度则是先减小然后再增大，而延伸率随高度变化不明显。铸造A356-T6铝合金的平均屈服强度、断裂强度、延伸率和断面收缩率分别为216．64MPa，224MPa，1．086％和0．194％。断口分析表明拉伸断口的表面分布着杂质、孔洞、铸造缩孔和氧化膜等缺陷，断口表面也存在开裂的由碳、氧、铁、镁、铝和硅元素形成的复合粒子。铸造A356-T6铝合金在拉伸过程中，裂纹萌生于共晶硅粒子与基体结合处，并沿枝晶胞之间的共晶区域进行扩展，当前进的裂纹遇到取向不一致的共晶硅粒子时，裂纹将截断共晶硅粒子。铸造A356-T6铝合金拉伸断裂方式为沿胞（即穿晶）断裂的准解理断。
2006, 35(10):1625-1628.
Abstract:
A two-step procedure was used for the preparation of the modified Ti/TiO2-Pt electrodes. The first step was anodisation of the titanium substrate to produce oxide film, and the second step was cathodic deposition Pt. The Ti/TiO2-Pt electrodes with nanocrystalline Pt films were obtained by galvanostatic deposit from H2PtCl4 and HCl solutions containing organic at 298 K~343 K. The mean grain sizes of Pt particles were 80 nm~130 nm. The surfaces of the as-prepared anodes before and after Pt coating were investigated by field emission scanning electron microscope scanning (FE-SEM) and X-ray diffraction (XRD). The parameters such as temperature and pH were discussed. The results show that the catalytic activity of n-TiO2 is remarkably improved by Pt doping and will increase further with prolonging of Pt deposition time.
A two-step procedure was used for the preparation of the modified Ti/TiO2-Pt electrodes. The first step was anodisation of the titanium substrate to produce oxide film, and the second step was cathodic deposition Pt. The Ti/TiO2-Pt electrodes with nanocrystalline Pt films were obtained by galvanostatic deposit from H2PtCl4 and HCl solutions containing organic at 298 K~343 K. The mean grain sizes of Pt particles were 80 nm~130 nm. The surfaces of the as-prepared anodes before and after Pt coating were investigated by field emission scanning electron microscope scanning (FE-SEM) and X-ray diffraction (XRD). The parameters such as temperature and pH were discussed. The results show that the catalytic activity of n-TiO2 is remarkably improved by Pt doping and will increase further with prolonging of Pt deposition time.
27 Preparation and Kinetics Mechanism of Y2BaCuO5 Nano-CrystaUites Synthesized by Sonochemical Process
2006, 35(10):1632-1634.
Abstract:
Nanocrystalline Y2BaCuO5 was prepared by a wet sonochemical process using Y2O3, CuCl2 and BaCl2 as starting material. The influence of ultrasonic power on the crystallization and synthesized activation energy of Y2BaCuO5 were particularly investigated. Results show that the particle size and synthesized activation energy of Y2BaCuO5 decrease with the increase of ultrasonic power. Upon increasing of ultrasonic power from 100 W to 300 W, the particle size and synthesized activation energy of Y2BaCuO5 decrease from 50 nm to 30 nm and from 65 kJ/mol to 47 kJ/mol, respectively.
Nanocrystalline Y2BaCuO5 was prepared by a wet sonochemical process using Y2O3, CuCl2 and BaCl2 as starting material. The influence of ultrasonic power on the crystallization and synthesized activation energy of Y2BaCuO5 were particularly investigated. Results show that the particle size and synthesized activation energy of Y2BaCuO5 decrease with the increase of ultrasonic power. Upon increasing of ultrasonic power from 100 W to 300 W, the particle size and synthesized activation energy of Y2BaCuO5 decrease from 50 nm to 30 nm and from 65 kJ/mol to 47 kJ/mol, respectively.
2006, 35(10):1635-1638.
Abstract:
采用混合盐反应工艺制备了A356／TiB2铝基复合材料，通过OM，XRD，SEM，TEM和力学拉伸试验等材料分析方法测试了所合成复合材料的微观组织和力学性能。研究表明：K2TiF6和KBF4混合盐在A356铝合金熔体温度850℃时反应生成的增强体为棒状和粒状TiB2，并在基体中呈均匀弥散分布，增强体与基体间未发生界面反应。由于原位TiB2颗粒的强化和细化晶粒作用，使复合材料的力学性能明显提高，经热处理后共晶Si发生球化。复合材料拉伸断口呈韧性断裂特征，增强颗粒与基体间界面的破坏以脱开机制为主。
采用混合盐反应工艺制备了A356／TiB2铝基复合材料，通过OM，XRD，SEM，TEM和力学拉伸试验等材料分析方法测试了所合成复合材料的微观组织和力学性能。研究表明：K2TiF6和KBF4混合盐在A356铝合金熔体温度850℃时反应生成的增强体为棒状和粒状TiB2，并在基体中呈均匀弥散分布，增强体与基体间未发生界面反应。由于原位TiB2颗粒的强化和细化晶粒作用，使复合材料的力学性能明显提高，经热处理后共晶Si发生球化。复合材料拉伸断口呈韧性断裂特征，增强颗粒与基体间界面的破坏以脱开机制为主。
Wei Yuanjuan
,
Yan Kangping
,
Zhou Cheng
,
Cao Ya
,
Wang Wei
,
Tian Jian
,
Zhou Jumei
,
Ji Hua
,
Sang Ge
2006, 35(10):1639-1642.
Abstract:
首次选用镍作为中间催化剂,采用吸附还原成长法制备纳米Ir/SPE电极,并就镀浴温度和pH值、H2IrCl6浓度、NaBH4与H2IrCl6配比对电极制备的影响作了深入研究。研究表明:采用吸附还原成长法,以Ni作为中间催化剂,浓度为22mmol·L-1NaBH4与浓度为6mmol·L-1H2IrCl6的混合液作为镀浴,亦即NaBH4与H2IrCl6配比为3.6,pH值为8,镀浴温度为40℃,镀浴时间为24h的条件下,循环镀覆3次,可获得致密、均匀,具有良好电解性能的纳米级Ir/SPE电极。
首次选用镍作为中间催化剂,采用吸附还原成长法制备纳米Ir/SPE电极,并就镀浴温度和pH值、H2IrCl6浓度、NaBH4与H2IrCl6配比对电极制备的影响作了深入研究。研究表明:采用吸附还原成长法,以Ni作为中间催化剂,浓度为22mmol·L-1NaBH4与浓度为6mmol·L-1H2IrCl6的混合液作为镀浴,亦即NaBH4与H2IrCl6配比为3.6,pH值为8,镀浴温度为40℃,镀浴时间为24h的条件下,循环镀覆3次,可获得致密、均匀,具有良好电解性能的纳米级Ir/SPE电极。
2006, 35(10):1643-1646.
Abstract:
Carbon nanotube was used as a preventing agent to prepare Ni/carbon nanotube composite nanocoatings. Effect of carbon nanotube content in electrolyte on average grain size, microstructure, microhardness and antiwear properties of the Ni/carbon nanotube composite nanocoatings was investigated. The results indicate that average grain size and microstructure of the Ni/carbon nanotube composite nanocoatings are mainly controlled by carbon nanotube content in electrolyte. The Ni/carbon nanotube composite nanocoating has an average grain size of about 16 nm as the carbon nanotube content in electrolyte is 4 wt%. The wear behaviour and microhardness of the Ni/carbon nanotube composite nanocoatings is closely related to the average grain sizes and microstructures of the Ni/carbon nanotube composite nanocoatings. The excellent antiwear and mechanical properties of the Ni/carbon nanotube composite nanocoatings are attributed to the small grains and compact microstructures of the Ni/matrix composite nanocoatings caused by carbon nanotube used as a preventing agent.
Carbon nanotube was used as a preventing agent to prepare Ni/carbon nanotube composite nanocoatings. Effect of carbon nanotube content in electrolyte on average grain size, microstructure, microhardness and antiwear properties of the Ni/carbon nanotube composite nanocoatings was investigated. The results indicate that average grain size and microstructure of the Ni/carbon nanotube composite nanocoatings are mainly controlled by carbon nanotube content in electrolyte. The Ni/carbon nanotube composite nanocoating has an average grain size of about 16 nm as the carbon nanotube content in electrolyte is 4 wt%. The wear behaviour and microhardness of the Ni/carbon nanotube composite nanocoatings is closely related to the average grain sizes and microstructures of the Ni/carbon nanotube composite nanocoatings. The excellent antiwear and mechanical properties of the Ni/carbon nanotube composite nanocoatings are attributed to the small grains and compact microstructures of the Ni/matrix composite nanocoatings caused by carbon nanotube used as a preventing agent.
2006, 35(10):1647-1650.
Abstract:
研究了（TiB＋TiC）／Ti6242基复合材料在550℃，600℃和650℃空气中恒温氧化行为。用X射线衍射仪（XRD）和配有能谱仪（EDS）的扫描电子显微镜（SEM）对氧化层表面的相组成、形貌以及氧化层剖面的显微结构进行了分析，并分析了各元素对钛基复合材料氧化动力学行为的影响。结果表明：（TiB＋TiC）／Ti6242基复合材料的氧化层由一系列薄层组成：增强体TiB提高抗氧化性优于TiC，加工可以提高其抗氧化性；氧化动力学曲线主要为抛物线类型。
研究了（TiB＋TiC）／Ti6242基复合材料在550℃，600℃和650℃空气中恒温氧化行为。用X射线衍射仪（XRD）和配有能谱仪（EDS）的扫描电子显微镜（SEM）对氧化层表面的相组成、形貌以及氧化层剖面的显微结构进行了分析，并分析了各元素对钛基复合材料氧化动力学行为的影响。结果表明：（TiB＋TiC）／Ti6242基复合材料的氧化层由一系列薄层组成：增强体TiB提高抗氧化性优于TiC，加工可以提高其抗氧化性；氧化动力学曲线主要为抛物线类型。
2006, 35(10):1651-1655.
Abstract:
描述了用单片试样法研究合金成分对Zr．Sn．Nb．Fe．Cr系锆合金在350℃，LiOH水溶液和400℃蒸汽中耐腐蚀性能影响的结果。这种单片试样，类似于成分梯度材料，是用真空电子束焊接方法将成分不同的锆合金小条交替焊接而成。研究结果表明：在合金成分最优化的地方，经400℃过热蒸汽腐蚀120d的增重与Zr-4相当；而经350℃，LiOH水溶液中腐蚀110d后，耐腐蚀性能优于Zr-4，也略优于ZIRLO，E635等Zr-Sn-Nb-Fe系合金，与N18的耐腐蚀性能相当。这种合金的成分为Zr-1．1-1．4Sn-0．2-0．3Nb-0．12-0．2Fe-0．02～0．03Cr。在LiOH水溶液中腐蚀时，成分对锆合金耐腐蚀性能影响的规律显得更为复杂，合金成分的微小变化就可能引起耐腐蚀性能的明显差别，这或许还包含着合金元素过饱和固溶在α-Zr中产生的影响。用单片试样法研究成分对锆合金耐腐蚀性能的影响可以得到非常丰富的信息，便于发现耐腐蚀性能更优良的新锆合金。
描述了用单片试样法研究合金成分对Zr．Sn．Nb．Fe．Cr系锆合金在350℃，LiOH水溶液和400℃蒸汽中耐腐蚀性能影响的结果。这种单片试样，类似于成分梯度材料，是用真空电子束焊接方法将成分不同的锆合金小条交替焊接而成。研究结果表明：在合金成分最优化的地方，经400℃过热蒸汽腐蚀120d的增重与Zr-4相当；而经350℃，LiOH水溶液中腐蚀110d后，耐腐蚀性能优于Zr-4，也略优于ZIRLO，E635等Zr-Sn-Nb-Fe系合金，与N18的耐腐蚀性能相当。这种合金的成分为Zr-1．1-1．4Sn-0．2-0．3Nb-0．12-0．2Fe-0．02～0．03Cr。在LiOH水溶液中腐蚀时，成分对锆合金耐腐蚀性能影响的规律显得更为复杂，合金成分的微小变化就可能引起耐腐蚀性能的明显差别，这或许还包含着合金元素过饱和固溶在α-Zr中产生的影响。用单片试样法研究成分对锆合金耐腐蚀性能的影响可以得到非常丰富的信息，便于发现耐腐蚀性能更优良的新锆合金。
2006, 35(10):1656-1660.
Abstract:
It is well known that direct copper plating on ABS plastics has found widely industrial application for eliminating plating. The Pd/Sn colloids for direct copper plating have better dispersivity and smaller size than the colloids for electroless electroless Ultraviolet-visible absorption spectrometry, nanophox, and stereoscopic microscopy were used to characterize the colloids. The good dispersivity colloids have excellent catalysis for direct copper plating and its UV-VIS peaks are broadened. In order to enhance the dispersivity and minimize the particle size, vanillin was added to colloids solution in the present investigation.
It is well known that direct copper plating on ABS plastics has found widely industrial application for eliminating plating. The Pd/Sn colloids for direct copper plating have better dispersivity and smaller size than the colloids for electroless electroless Ultraviolet-visible absorption spectrometry, nanophox, and stereoscopic microscopy were used to characterize the colloids. The good dispersivity colloids have excellent catalysis for direct copper plating and its UV-VIS peaks are broadened. In order to enhance the dispersivity and minimize the particle size, vanillin was added to colloids solution in the present investigation.
2006, 35(10):1661-1664.
Abstract:
This paper studied the deposit process of electroless Ni-P on die casting magnesium alloys using SEM and GDA spectrum analysis instrument etc. The results indicated that pre-treatment made magnesium alloys surface netted-porous, loose MgF2 and AIF3 layer formed after activation process. The initial deposit process of electroless Ni-P was precipitation of Ni without P atom, followed by Ni nucleating and growing up, the Ni of self-catalysis formed, the nickel phosphorus began to co-deposit. There exited mixing layer composed of complex compound, fluoride, plating liquid and Ni in the initial deposit coating.
This paper studied the deposit process of electroless Ni-P on die casting magnesium alloys using SEM and GDA spectrum analysis instrument etc. The results indicated that pre-treatment made magnesium alloys surface netted-porous, loose MgF2 and AIF3 layer formed after activation process. The initial deposit process of electroless Ni-P was precipitation of Ni without P atom, followed by Ni nucleating and growing up, the Ni of self-catalysis formed, the nickel phosphorus began to co-deposit. There exited mixing layer composed of complex compound, fluoride, plating liquid and Ni in the initial deposit coating.
2006, 35(10):1665-1668.
Abstract:
采用电子束物理气相沉积（EB-PVD）技术，成功制备了0．2mm厚由24层Ti．Al和23层Nb交替叠加而成的Ti—AI／Nb层板复合材料，并采用扫描电子显微镜（SEM）等测试手段，对其物相组成和断口形貌等与Ti-Al单层材料进行了对比分析。结果表明，Ti—AI／Nb层板复合材料的界面明晰，层间距约为8gm；Ti-AI层由γ相和τ相组成，其成分呈梯度变化，且平均成分与原始铸锭的成分偏差较大，但未发现Ti-Al单层材料中看到的分层现象；Ti-AI／Nb层板复合材料具有比Ti-Al单层材料更好的韧性。
采用电子束物理气相沉积（EB-PVD）技术，成功制备了0．2mm厚由24层Ti．Al和23层Nb交替叠加而成的Ti—AI／Nb层板复合材料，并采用扫描电子显微镜（SEM）等测试手段，对其物相组成和断口形貌等与Ti-Al单层材料进行了对比分析。结果表明，Ti—AI／Nb层板复合材料的界面明晰，层间距约为8gm；Ti-AI层由γ相和τ相组成，其成分呈梯度变化，且平均成分与原始铸锭的成分偏差较大，但未发现Ti-Al单层材料中看到的分层现象；Ti-AI／Nb层板复合材料具有比Ti-Al单层材料更好的韧性。
2006, 35(10):1669-1672.
Abstract:
研究了高能球磨过程中A1203相结构的变化。结果表明：随着球磨时间的延长，粉末中发生了γ-Al2O3→a—Al2O3的转变，这一点对于降低碳热还原反应激活能是不利的；高能球磨20h，A1203部分非晶化，而且有立方结构AIN生成：高能球磨过程中形成的AIN，结构不同于常规六方结构氮化铝；增加球磨能量，立方AIN生成量增加；650r／min高能球磨40h，AIN生成量达到72％。
研究了高能球磨过程中A1203相结构的变化。结果表明：随着球磨时间的延长，粉末中发生了γ-Al2O3→a—Al2O3的转变，这一点对于降低碳热还原反应激活能是不利的；高能球磨20h，A1203部分非晶化，而且有立方结构AIN生成：高能球磨过程中形成的AIN，结构不同于常规六方结构氮化铝；增加球磨能量，立方AIN生成量增加；650r／min高能球磨40h，AIN生成量达到72％。
Wu Yifang
,
Feng Yong
,
Li Jinshan
,
Tang Huiping
,
Yan Guo
,
Chen Shaokai
,
Xu Hongliang
,
Li Chengshan
,
Lu Yafeng
2006, 35(10):1673-1676.
Abstract:
The bulk MgB2 was prepared by the high energy ball-milled Mg/B precursor powder. The influences of the synthesis parameters, i.e., the milling time, the heat-treatment temperature and the holding time, on the density of bulk MgB2 were investigated. The densification behavior of the Mg and B reaction sinter was analyzed in theory.
The bulk MgB2 was prepared by the high energy ball-milled Mg/B precursor powder. The influences of the synthesis parameters, i.e., the milling time, the heat-treatment temperature and the holding time, on the density of bulk MgB2 were investigated. The densification behavior of the Mg and B reaction sinter was analyzed in theory.
2006, 35(10):1677-1680.
Abstract:
为实现镁合金AZ31B与钛合金Ti6A14V的可靠连接，研究了两者以Al为中间层的瞬间液相扩散焊接头的微观结构与连接强度。研究结果表明：当焊接时间为180min时，焊接温度是影响界面反应热力学与动力学的主要参数，其对接头的微观组织、接头界面新生相构成与连接强度有重要影响。保温温度低于450℃时，AZ3IB／AI界面无液相产生，无法实现AZ31B与Ti6A14V的可靠连接；保温温度在450℃～480℃变化时，温度对AZ31B／Al／Ti6A14V界面反应的动力学因素有明显影响，且直接决定了焊后接头新生相的构成与分布。470℃保温180min的接头剪切强度较高（72．4MPa），达到AZ31B母材（86MPa）的84．2％。
为实现镁合金AZ31B与钛合金Ti6A14V的可靠连接，研究了两者以Al为中间层的瞬间液相扩散焊接头的微观结构与连接强度。研究结果表明：当焊接时间为180min时，焊接温度是影响界面反应热力学与动力学的主要参数，其对接头的微观组织、接头界面新生相构成与连接强度有重要影响。保温温度低于450℃时，AZ3IB／AI界面无液相产生，无法实现AZ31B与Ti6A14V的可靠连接；保温温度在450℃～480℃变化时，温度对AZ31B／Al／Ti6A14V界面反应的动力学因素有明显影响，且直接决定了焊后接头新生相的构成与分布。470℃保温180min的接头剪切强度较高（72．4MPa），达到AZ31B母材（86MPa）的84．2％。
