Volume 0,Issue 9,2003 Table of Contents
2003(9):677-680.
Abstract:
综述了粉末冶金钛合金致密化工艺及致密化机理研究的新进展。粉末冶金钛合金致密化工艺除采用传统的热等静压工艺外，注射成型、激光成型等新技术的应用可以得到相对密度达99％的烧结件，其拉伸性能达到甚至超过熔锻钛合金的水平；致密化理论方面的研究除扩散、蠕变及屈服机制外，钛合金中还有相变致密化机制与多组元合金元素的强化致密化机制。其中当粉末钛合金在理／口两相区温度下进行循环热压时，相变致密化起主要作用。当多组元粉末钛合金烧结时，促进液相形成或提供扩散通道的合金元素起强化致密化作用。这两种致密化机制在粉末钛合金烧结的实际应用中有重要意义。
综述了粉末冶金钛合金致密化工艺及致密化机理研究的新进展。粉末冶金钛合金致密化工艺除采用传统的热等静压工艺外，注射成型、激光成型等新技术的应用可以得到相对密度达99％的烧结件，其拉伸性能达到甚至超过熔锻钛合金的水平；致密化理论方面的研究除扩散、蠕变及屈服机制外，钛合金中还有相变致密化机制与多组元合金元素的强化致密化机制。其中当粉末钛合金在理／口两相区温度下进行循环热压时，相变致密化起主要作用。当多组元粉末钛合金烧结时，促进液相形成或提供扩散通道的合金元素起强化致密化作用。这两种致密化机制在粉末钛合金烧结的实际应用中有重要意义。
2003(9):681-685.
Abstract:
The main types,met ho ds of productio n,and failure modes for high-temperature protective coatings a re briefly considered.The paper emphasizes the importance of alumin ide coating s for high-temperature p rotection and of studies of high-tem perature oxidati on of the high-temperature coatings in general.
The main types,met ho ds of productio n,and failure modes for high-temperature protective coatings a re briefly considered.The paper emphasizes the importance of alumin ide coating s for high-temperature p rotection and of studies of high-tem perature oxidati on of the high-temperature coatings in general.
2003(9):689-692.
Abstract:
Numerical simulation of pulsed magn etic flux density and L orentz force i n the solidifying sample inside a str aight solenoid coil during the solidification under tra nsient pulsed magnetic field was stu died using ANS YS5.5software.The simulation showed that both the axial and radial distribut ions of th e pulsed magnetic flux density and th e Lorentz force,during the sol idifi cation under pulsed magnetic field,were not only asymmetrical but also n onuniform.The simulation method is generally useful for studying solid ificatio n behaviors and structures during solidification under transient pulsed magnetic field.
Numerical simulation of pulsed magn etic flux density and L orentz force i n the solidifying sample inside a str aight solenoid coil during the solidification under tra nsient pulsed magnetic field was stu died using ANS YS5.5software.The simulation showed that both the axial and radial distribut ions of th e pulsed magnetic flux density and th e Lorentz force,during the sol idifi cation under pulsed magnetic field,were not only asymmetrical but also n onuniform.The simulation method is generally useful for studying solid ificatio n behaviors and structures during solidification under transient pulsed magnetic field.
2003(9):693-698.
Abstract:
In the implantation of lithium ions i nto a nd dissipation from lithium/me taloxide Positive material,the voltage and sta bility of the material can be analyzed and predicted using the first principle m ethods.This paper reviews the theoretical background of first principle methods and presents the results of a recent study of LiCoO 2 positive electrode.The investigation of Li x NiO 2 and multi-element substitution should be a focal point of future rese arch .
In the implantation of lithium ions i nto a nd dissipation from lithium/me taloxide Positive material,the voltage and sta bility of the material can be analyzed and predicted using the first principle m ethods.This paper reviews the theoretical background of first principle methods and presents the results of a recent study of LiCoO 2 positive electrode.The investigation of Li x NiO 2 and multi-element substitution should be a focal point of future rese arch .
2003(9):699-702.
Abstract:
In this paper,an ideal liquid model of s ym metrically colliding was taken to analyze the distribution character of natural strain field.The results show that the strain at stagnation point is infinite, and stra in saltaion is completed in fivefold jet thickness at explosive welding interface.
In this paper,an ideal liquid model of s ym metrically colliding was taken to analyze the distribution character of natural strain field.The results show that the strain at stagnation point is infinite, and stra in saltaion is completed in fivefold jet thickness at explosive welding interface.
2003(9):703-706.
Abstract:
用示差扫描热分析仪(DSC)、X射线衍射仪(XRD)和光学显微镜系统研究了热处理和热循环对Ru-49Ta高温形状记忆合金马氏体相变行为的影响。结果表明：Ru-49T8合金的Ms(马氏体相变开始温度)和Af(马氏体逆相变结束温度)分别为1065℃和1085℃，相变温度范围(Ms-Mf)为15℃，相变热滞和相变热比较小，分别为22℃和2J／g。热处理对Ru-49Ta合金马氏体相变行为影响不大，该合金的马氏体相稳定性良好，不存在时效效应，相变方式为孪生。热循环对Ru-49Ta合金马氏体相变温度和热滞影响不大，随热循环的进行，相变热有所减少。
用示差扫描热分析仪(DSC)、X射线衍射仪(XRD)和光学显微镜系统研究了热处理和热循环对Ru-49Ta高温形状记忆合金马氏体相变行为的影响。结果表明：Ru-49T8合金的Ms(马氏体相变开始温度)和Af(马氏体逆相变结束温度)分别为1065℃和1085℃，相变温度范围(Ms-Mf)为15℃，相变热滞和相变热比较小，分别为22℃和2J／g。热处理对Ru-49Ta合金马氏体相变行为影响不大，该合金的马氏体相稳定性良好，不存在时效效应，相变方式为孪生。热循环对Ru-49Ta合金马氏体相变温度和热滞影响不大，随热循环的进行，相变热有所减少。
2003(9):707-710.
Abstract:
采用磁控溅射方法在p-Si(111)衬底上淀积5nmPt膜，分别在350℃-600℃退火。原子力显微镜(AFM)观察和x射线光电子谱(XPS)分析表明，随退火温度的增加，平坦的薄膜表面变得粗糙，其相分布由Pt-Pt2Si-Ptsi变为Pt Pt2Si PtSi-Ptsi。
采用磁控溅射方法在p-Si(111)衬底上淀积5nmPt膜，分别在350℃-600℃退火。原子力显微镜(AFM)观察和x射线光电子谱(XPS)分析表明，随退火温度的增加，平坦的薄膜表面变得粗糙，其相分布由Pt-Pt2Si-Ptsi变为Pt Pt2Si PtSi-Ptsi。
Zhang Xiaocong
,
Li Chengshan
,
Zhang Pingxiang
,
Zhou Lian
,
Feng Yong
,
Wu Yifang
,
Wu Xuan
,
Shao Huiming
,
2003(9):715-718.
Abstract:
The influence of the phase assemblag e of precursor powder on microstructures and the properties of Bi (Pb)-2223/Ag tapes has been studied.The phase assemblage was controlled by changing the final c alcination temperature.The r esult s show that a precursor powder containing mainly the Bi (Pb)-2212ph ase and some other second phases which include(Sr,Ca )CuO and Ca 2 PbO 4 phase,and without any2201and 2223phases is considered a g ood choic e for the fabrication of hig h J c Bi (Pb)-2223/Ag tapes.Accordingly,calcination of the precursor pow der just below the form ation temperature of 2223phase is th e most favorabl e.A maximum critical current density of 12kA/cm 2 was obtained.
The influence of the phase assemblag e of precursor powder on microstructures and the properties of Bi (Pb)-2223/Ag tapes has been studied.The phase assemblage was controlled by changing the final c alcination temperature.The r esult s show that a precursor powder containing mainly the Bi (Pb)-2212ph ase and some other second phases which include(Sr,Ca )CuO and Ca 2 PbO 4 phase,and without any2201and 2223phases is considered a g ood choic e for the fabrication of hig h J c Bi (Pb)-2223/Ag tapes.Accordingly,calcination of the precursor pow der just below the form ation temperature of 2223phase is th e most favorabl e.A maximum critical current density of 12kA/cm 2 was obtained.
2003(9):719-722.
Abstract:
Th e Nanometer TiO 2 powder was put into the unsaturated p olyester resin for the simultaneous mo dification of strength-ening and flexibilizing.The impact strength was used to characterize th e ductility of the nano-TiO 2/UPR.It was found that the resin had the apparent brittleness-ductility t ransition phenomenon,a nd the content of TiO 2 at the brittleness-ductility transition point,was 6wt%.The bending stre ngth and impact strength of the nano-TiO 2/UPR were increased by 55%and 46%respectively compared with those of UPR.The micro observation of the impact fracture i ndicaties that,the fracture pattern of the nano-TiO 2/UPR changes from typical brittleness to typical toughness fracture near th e critical point.
Th e Nanometer TiO 2 powder was put into the unsaturated p olyester resin for the simultaneous mo dification of strength-ening and flexibilizing.The impact strength was used to characterize th e ductility of the nano-TiO 2/UPR.It was found that the resin had the apparent brittleness-ductility t ransition phenomenon,a nd the content of TiO 2 at the brittleness-ductility transition point,was 6wt%.The bending stre ngth and impact strength of the nano-TiO 2/UPR were increased by 55%and 46%respectively compared with those of UPR.The micro observation of the impact fracture i ndicaties that,the fracture pattern of the nano-TiO 2/UPR changes from typical brittleness to typical toughness fracture near th e critical point.
2003(9):723-726.
Abstract:
The effects of an electric field appl ied du ring solution treatment on the precipitation kinetics in Al-Li all oy 2090h ave been studied using differential scanning calorimetry(DSC).It is found tha t electric field decreases the peak temperatures of?' and T 1 phases precipitation,bringing their curves forward.It le ssens the enthalp y of T 1 precipitation,while keeping that of?' precipitation unchanged.At the sa m e time,the electric field increases the rates of?' and T 1 precipitation in the first stages,while decreases those in the last stages .An electric field also reduces the activation energies of?' and T 1 phases precipitations.It is though t that the electric field increases t he concentration of vacancies and the hence solubility of alloying elements,there by decreasing the activation energies of these two precipitation mechanisms.
The effects of an electric field appl ied du ring solution treatment on the precipitation kinetics in Al-Li all oy 2090h ave been studied using differential scanning calorimetry(DSC).It is found tha t electric field decreases the peak temperatures of?' and T 1 phases precipitation,bringing their curves forward.It le ssens the enthalp y of T 1 precipitation,while keeping that of?' precipitation unchanged.At the sa m e time,the electric field increases the rates of?' and T 1 precipitation in the first stages,while decreases those in the last stages .An electric field also reduces the activation energies of?' and T 1 phases precipitations.It is though t that the electric field increases t he concentration of vacancies and the hence solubility of alloying elements,there by decreasing the activation energies of these two precipitation mechanisms.
2003(9):727-731.
Abstract:
考察了不同成分的Ti-Fe-Mo-Mn-Nb-Zr合金的压缩强度、硬度，得到了高压缩强度，硬度与牙本质相近的钛合金。在综合考虑钛合金成本、力学性能的基础上，采用模糊推理系统建立了钛合金中的元素质量百分含量与硬度之间的关系，并通过实验法进行了验证，预测结果与实际测定结果的对比是令人满意的。在保证性能的基础上，利用训练好的模糊推理系统对材料的成分进行优化，减少贵重元素的加入量。
考察了不同成分的Ti-Fe-Mo-Mn-Nb-Zr合金的压缩强度、硬度，得到了高压缩强度，硬度与牙本质相近的钛合金。在综合考虑钛合金成本、力学性能的基础上，采用模糊推理系统建立了钛合金中的元素质量百分含量与硬度之间的关系，并通过实验法进行了验证，预测结果与实际测定结果的对比是令人满意的。在保证性能的基础上，利用训练好的模糊推理系统对材料的成分进行优化，减少贵重元素的加入量。
Bai Xinde
,
Liu Xiaoyang
,
An Jin
,
Jin Zhaoxiong Chen Baoshan
,
Wu Zhiming
,
Liu Fangyan
,
Tong Shenxiu
2003(9):732-735.
Abstract:
The abnormal blu e oxide films occurred at the heat-affected zone of zircalloy-4cladding tube af ter electron beam welding,were studied using XPS,EDX,TEM.The resu lts indica te that iron and tin in the a bnormal oxide film exist in the form o f Fe 2 O 3 ,SnO 2 ,and the ratio of Fe to Sn in abnormal blue oxid e film is higher than that of the norma l one.These results will provide the basis of the further researc h.
The abnormal blu e oxide films occurred at the heat-affected zone of zircalloy-4cladding tube af ter electron beam welding,were studied using XPS,EDX,TEM.The resu lts indica te that iron and tin in the a bnormal oxide film exist in the form o f Fe 2 O 3 ,SnO 2 ,and the ratio of Fe to Sn in abnormal blue oxid e film is higher than that of the norma l one.These results will provide the basis of the further researc h.
2003(9):736-739.
Abstract:
The effect of Sc on microstructure an d tensile p roperties of Al-Li-Cu-Mg-Ag-Zr alloy has been studied using o ptical and t ransmission electron microscopy and scanning electron microscopy.The results sh ow that addition of Sc may refine the gra in size,and encourages the homogeneou s precipitation of T 1 phase throughout the matrix,The wid espread precipitation of T 1 phase promotes homogeneous deforma tion thereby improving the mechanical pr operties of these trace-Sc containi ng.
The effect of Sc on microstructure an d tensile p roperties of Al-Li-Cu-Mg-Ag-Zr alloy has been studied using o ptical and t ransmission electron microscopy and scanning electron microscopy.The results sh ow that addition of Sc may refine the gra in size,and encourages the homogeneou s precipitation of T 1 phase throughout the matrix,The wid espread precipitation of T 1 phase promotes homogeneous deforma tion thereby improving the mechanical pr operties of these trace-Sc containi ng.
2003(9):740-743.
Abstract:
The cavitat io n erosion of TiNiNb alloy and 0Cr13Ni5Mo stainless steel wa s investigated u sing rotating disc e quipment.To simulate the effect of the collapse of vapor c a vities or bubbles,a Rockwell hardness tester was used to exert a load on th e surface areas of the alloys.The results show that the cavitation ero sion resi stance of TiNiNb is greater than that of 0Cr13Ni5Mo.The TiNiNb a lloy is mo re elastic than0Cr13Ni5Mo stainless steel in the in dentation test,thereby permitting TiNiNb to absorb and relieve more imp act energy during cavitation er osion.This reduces volume loss,a nd leads to excellent cavitations erosion res istance.
The cavitat io n erosion of TiNiNb alloy and 0Cr13Ni5Mo stainless steel wa s investigated u sing rotating disc e quipment.To simulate the effect of the collapse of vapor c a vities or bubbles,a Rockwell hardness tester was used to exert a load on th e surface areas of the alloys.The results show that the cavitation ero sion resi stance of TiNiNb is greater than that of 0Cr13Ni5Mo.The TiNiNb a lloy is mo re elastic than0Cr13Ni5Mo stainless steel in the in dentation test,thereby permitting TiNiNb to absorb and relieve more imp act energy during cavitation er osion.This reduces volume loss,a nd leads to excellent cavitations erosion res istance.
2003(9):744-747.
Abstract:
采用低温强碱法制备了粒径为40nm左右的高纯纳米四方多晶氧化锆粉体。对于纳米四方多晶氧化锆粉体在不同条件下的Zeta电位的测试表明，聚电解质分散剂聚丙烯酸铵(NH4PAA)使粉体等电点降低，对聚电解质分散剂聚丙烯酸铵在纳米四方多晶氧化锆粉体上的等温吸附研究发现，由于聚电解质分散剂的作用，悬浮体中纳米氧化锆粉体颗粒表面的电动特性发生了显著的变化，其等电点向pH值降低的方向移动了3．5。分散剂用量为1．0％(对于粉体，按质量)时，悬浮体稳定性较好，该纳米粉体浆料的流变特性得到明显的改善。
采用低温强碱法制备了粒径为40nm左右的高纯纳米四方多晶氧化锆粉体。对于纳米四方多晶氧化锆粉体在不同条件下的Zeta电位的测试表明，聚电解质分散剂聚丙烯酸铵(NH4PAA)使粉体等电点降低，对聚电解质分散剂聚丙烯酸铵在纳米四方多晶氧化锆粉体上的等温吸附研究发现，由于聚电解质分散剂的作用，悬浮体中纳米氧化锆粉体颗粒表面的电动特性发生了显著的变化，其等电点向pH值降低的方向移动了3．5。分散剂用量为1．0％(对于粉体，按质量)时，悬浮体稳定性较好，该纳米粉体浆料的流变特性得到明显的改善。
2003(9):748-751.
Abstract:
研究了超细不锈钢纤维的制备工艺和产品性能，结果表明：集束拉拔法能够制备超细不锈钢纤维，但由于加工过程的不均匀变形导致纤维丝呈不规则圆形。在相同的真应变条件下，12μm，8μm和6μm纤维的单丝断裂强力随真应变的增加而增加，抗拉强度随着纤维丝径的减小而显著增加，在12μm处达到极大值后又随着纤维丝径的减小而显著降低。3种规格的纤维表面都存在颗粒状的碳化物，碳化物在拉伸过程中随着纤维的减径而被带到表面或近表面处，它不仅使纤维芯丝严重不均匀，还会导致纤维沿颗粒处损坏至断裂，这也是8μm和6μm纤维抗拉强度相对低的原因。
研究了超细不锈钢纤维的制备工艺和产品性能，结果表明：集束拉拔法能够制备超细不锈钢纤维，但由于加工过程的不均匀变形导致纤维丝呈不规则圆形。在相同的真应变条件下，12μm，8μm和6μm纤维的单丝断裂强力随真应变的增加而增加，抗拉强度随着纤维丝径的减小而显著增加，在12μm处达到极大值后又随着纤维丝径的减小而显著降低。3种规格的纤维表面都存在颗粒状的碳化物，碳化物在拉伸过程中随着纤维的减径而被带到表面或近表面处，它不仅使纤维芯丝严重不均匀，还会导致纤维沿颗粒处损坏至断裂，这也是8μm和6μm纤维抗拉强度相对低的原因。
2003(9):752-755.
Abstract:
Nanostructured W-La 2 O 3 composite powder was prepared by the high energy ball milling,or mechani ca l alloying(MA).Serially W-La 2 O 3 electrode materials were fabricate d by hot pressed sintering in vacuum .In each case the nanostructural evolutions was observed as function of milling tim e and sintering temperature using SEM,XRD and TEM.The results show that the si ntering densification depends on nanosize particle rearrangement ra sther than c onventional diffusion.The enhanced sinterability of MA W-L a 2 O 3 composite powder is attributed to their ultra-fine and homogeneously mixed state,high internal strain,as well as the sintering activation by impurity ele ments.
Nanostructured W-La 2 O 3 composite powder was prepared by the high energy ball milling,or mechani ca l alloying(MA).Serially W-La 2 O 3 electrode materials were fabricate d by hot pressed sintering in vacuum .In each case the nanostructural evolutions was observed as function of milling tim e and sintering temperature using SEM,XRD and TEM.The results show that the si ntering densification depends on nanosize particle rearrangement ra sther than c onventional diffusion.The enhanced sinterability of MA W-L a 2 O 3 composite powder is attributed to their ultra-fine and homogeneously mixed state,high internal strain,as well as the sintering activation by impurity ele ments.
2003(9):756-760.
Abstract:
Three types of thermal barrier coatin gs (TBCs )were prepared by plasma spray(PS)on GH536superalloy substrate with d ifferent layers.One is the traditional TBC wi th Ni22Cr10AlY as bond co at and ZrO 2-8wt%Y 2 O 3 (8YSZ)as top coat,the other two TBCs have a t riplex structure with comp osite layers of 8YSZ +Al 2 O 3 and ZrO 2 ,respectively.The static oxidatio n test and thermal shock tests were cond ucted to evaluate the oxidation kinetics and thermal shock cyclic lifetime of th e TBCs.With the different failure criterions,the failure mechanism of TBCs was discussed.The thermal shoc k resistance of state-of-the-art duplex TBCs is the best.It is indicated that the higher oxidation resis-tance is obtained by using of composite 8YSZ +Al 2 O 3 ceramic layer.It has the better oxid ation resistance if using 8YSZ +Al 2 O 3 as the inner composite layer of TBCs,comparing with as the out layer.
Three types of thermal barrier coatin gs (TBCs )were prepared by plasma spray(PS)on GH536superalloy substrate with d ifferent layers.One is the traditional TBC wi th Ni22Cr10AlY as bond co at and ZrO 2-8wt%Y 2 O 3 (8YSZ)as top coat,the other two TBCs have a t riplex structure with comp osite layers of 8YSZ +Al 2 O 3 and ZrO 2 ,respectively.The static oxidatio n test and thermal shock tests were cond ucted to evaluate the oxidation kinetics and thermal shock cyclic lifetime of th e TBCs.With the different failure criterions,the failure mechanism of TBCs was discussed.The thermal shoc k resistance of state-of-the-art duplex TBCs is the best.It is indicated that the higher oxidation resis-tance is obtained by using of composite 8YSZ +Al 2 O 3 ceramic layer.It has the better oxid ation resistance if using 8YSZ +Al 2 O 3 as the inner composite layer of TBCs,comparing with as the out layer.
2003(9):761-764.
Abstract:
以SnCl4^ 5H2O和SbCl3为原料，通过正交实验并借助于XRD，TEM等手段，研究了前驱物浓度、反应温度、保温时间和氨水滴加速率等工艺因素对水热合成锑掺杂SnO2纳米粉体的影响，探讨了不同分散处理工艺对纳米粉体分散性的影响。
以SnCl4^ 5H2O和SbCl3为原料，通过正交实验并借助于XRD，TEM等手段，研究了前驱物浓度、反应温度、保温时间和氨水滴加速率等工艺因素对水热合成锑掺杂SnO2纳米粉体的影响，探讨了不同分散处理工艺对纳米粉体分散性的影响。
2003(9):765-768.
Abstract:
The influence of milling rate in range from 125r/min to 225r/min and the ad dition of from 0%to 4. 5%of the process control agents ethanol,stearic acid on the mechanical alloyi ng of a Ti-Cr alloy h as been investigated.The results sh ow that the higher t he milling rate,the smaller the powders as other milling conditions are unchang ed.Ethanol as a useful process control a gent lowes the impurity level during M A processing,but results in reduced fining efficiency.The reco mended addition of ethanol is under 1.5%.The abrasion of either milling balls or milling j ar can be controlled by optimizing the milling r ate and selection the best proc ess co ntrol agent.
The influence of milling rate in range from 125r/min to 225r/min and the ad dition of from 0%to 4. 5%of the process control agents ethanol,stearic acid on the mechanical alloyi ng of a Ti-Cr alloy h as been investigated.The results sh ow that the higher t he milling rate,the smaller the powders as other milling conditions are unchang ed.Ethanol as a useful process control a gent lowes the impurity level during M A processing,but results in reduced fining efficiency.The reco mended addition of ethanol is under 1.5%.The abrasion of either milling balls or milling j ar can be controlled by optimizing the milling r ate and selection the best proc ess co ntrol agent.
Hu Lifa
,
,
A.Sulpice
,
E.Mossang
,
Li Chengshan
,
Ji Ping
,
Wu Yifang
,
Feng Yong
,
Zhang Pingxiang
,
Zhou Lian
2003(9):769-772.
Abstract:
Experimentally determined AC loss i n Bi2223tapes at 4.2K under applied D C magnetic field is discussed.Considered are the influences on the seif-field loss of:(1)The applied DC field(2).The resistivity of the sheath materia l.(3)The critical current and the number of superconducting filaments.All o f the experiments are performed at 4.2K and at appled magnetic fields of up to 5T.
Experimentally determined AC loss i n Bi2223tapes at 4.2K under applied D C magnetic field is discussed.Considered are the influences on the seif-field loss of:(1)The applied DC field(2).The resistivity of the sheath materia l.(3)The critical current and the number of superconducting filaments.All o f the experiments are performed at 4.2K and at appled magnetic fields of up to 5T.
