Volume 0,Issue 4,2002 Table of Contents
2002(4):241-245.
Abstract:
The CALPHAD technology,first principle method and Embedded Atom Method (EAM) in computer simulation of metals and alloys are outlined.Recent results of computer simulation for Ti2AlNb based alloy are reviewed.
The CALPHAD technology,first principle method and Embedded Atom Method (EAM) in computer simulation of metals and alloys are outlined.Recent results of computer simulation for Ti2AlNb based alloy are reviewed.
2002(4):246-251.
Abstract:
The development status of dental Ti, Ti alloys and Ti alloy porcetains, such as their physico mechanical properties, shaping techniques and equipments, and surface treatment, are reviewed. The present status of research and application of dental Ti and Ti alloy are discussed.
The development status of dental Ti, Ti alloys and Ti alloy porcetains, such as their physico mechanical properties, shaping techniques and equipments, and surface treatment, are reviewed. The present status of research and application of dental Ti and Ti alloy are discussed.
2002(4):252-256.
Abstract:
Mg Ni alloy is a promising candidate for hydrogen storage because of its high discharge capacity. But its applicability is restricted by its rapid capacity deterioration and charge discharge cycling limitations. Factors effecting Mg Ni electrode discharging capacity are analysed and several methods for improving the overall electrochemical performance are discussed.
Mg Ni alloy is a promising candidate for hydrogen storage because of its high discharge capacity. But its applicability is restricted by its rapid capacity deterioration and charge discharge cycling limitations. Factors effecting Mg Ni electrode discharging capacity are analysed and several methods for improving the overall electrochemical performance are discussed.
2002(4):257-260.
Abstract:
在440℃经多向锻造加工成7075铝合金锻件。研究了锻件的显微组织和力学性能随退火温度和T73回火的变化，TEM和SEM用于分析锻件的晶粒和第二相形态。多向和大变形锻造产生平均晶粒尺寸1．8μm的完全再结晶组织。390℃-450℃退火使晶粒长大到3μm，但位错和第二相分布没有明显改变，这时锻件展现出较低强度和较高延性。T73回火使锻件屈服强度和拉伸强度分别提高280％和210％，而延性同退火样相比并无明显下降，断裂韧性达到51MPam^1/2，可以认为这是沉淀强化的贡献。
在440℃经多向锻造加工成7075铝合金锻件。研究了锻件的显微组织和力学性能随退火温度和T73回火的变化，TEM和SEM用于分析锻件的晶粒和第二相形态。多向和大变形锻造产生平均晶粒尺寸1．8μm的完全再结晶组织。390℃-450℃退火使晶粒长大到3μm，但位错和第二相分布没有明显改变，这时锻件展现出较低强度和较高延性。T73回火使锻件屈服强度和拉伸强度分别提高280％和210％，而延性同退火样相比并无明显下降，断裂韧性达到51MPam^1/2，可以认为这是沉淀强化的贡献。
2002(4):261-265.
Abstract:
The microstructure of oxide film for new zirconium alloys was studied.The results show that the microstructure of oxide films is much alike from inner surface to outer surface for NZ2 and NZ8 alloys by different intermidiate annealling treatment.The effect of different annealling lies in that whether there are precipitates embedding in oxide,the higher the accumulative annealing parameters,the more the probability of precipitates embedding.The embedded precipitates promote oxide transition to monoclinal structure and promote cracking along the former alloys grain boundary.SEM shows that the oxide film grows in a inhomogeneous way.The film in the inner surface appears in morphology like Cauliflouer,which is realted to accelerating corrosion.The faster the corrosion,the bigger the "Cauliflower"in size is.The results obtained by this study comfirm that adopting low temperature working process can make further refining of precipitates size,and this is the effective way to improve corrosion resistance of new zirconium alloys.
The microstructure of oxide film for new zirconium alloys was studied.The results show that the microstructure of oxide films is much alike from inner surface to outer surface for NZ2 and NZ8 alloys by different intermidiate annealling treatment.The effect of different annealling lies in that whether there are precipitates embedding in oxide,the higher the accumulative annealing parameters,the more the probability of precipitates embedding.The embedded precipitates promote oxide transition to monoclinal structure and promote cracking along the former alloys grain boundary.SEM shows that the oxide film grows in a inhomogeneous way.The film in the inner surface appears in morphology like Cauliflouer,which is realted to accelerating corrosion.The faster the corrosion,the bigger the "Cauliflower"in size is.The results obtained by this study comfirm that adopting low temperature working process can make further refining of precipitates size,and this is the effective way to improve corrosion resistance of new zirconium alloys.
2002(4):266-269.
Abstract:
研究了TiC粒子增强的钛基复合材料的室温轴向高周疲劳性能。测试Kt=1的试样时采用的试验频率为76Hz，R＝0．06和R＝－1时，复合材料的室温疲劳强度分别为594MPa和494MPa。试验结果表明TiC粒子增强的钛基复合材料的室温高周疲劳性能与细晶组织的Ti-6Al-4V和IMI834的相当。复合材料内含有较细小的薄片状组织，这种组织为α β相互相交错构成，这种细小的α β相间的层状组织对于阻止疲劳裂纹的扩展和提高疲劳裂纹的扩展寿命有重要作用。退火后的复合材料疲劳裂纹扩展区规则且较宽广，从而也使复合材料具有较高的疲劳强度，疲劳裂纹扩展寿命延长。
研究了TiC粒子增强的钛基复合材料的室温轴向高周疲劳性能。测试Kt=1的试样时采用的试验频率为76Hz，R＝0．06和R＝－1时，复合材料的室温疲劳强度分别为594MPa和494MPa。试验结果表明TiC粒子增强的钛基复合材料的室温高周疲劳性能与细晶组织的Ti-6Al-4V和IMI834的相当。复合材料内含有较细小的薄片状组织，这种组织为α β相互相交错构成，这种细小的α β相间的层状组织对于阻止疲劳裂纹的扩展和提高疲劳裂纹的扩展寿命有重要作用。退火后的复合材料疲劳裂纹扩展区规则且较宽广，从而也使复合材料具有较高的疲劳强度，疲劳裂纹扩展寿命延长。
2002(4):270-273.
Abstract:
The influences of the 1%HF solution pretreatment on electrochemical properties of ZrCr0.7Ni1.3 were investigated.The results show that creak initiation and propagation and the increase of the specific surface area were accelerated due to the effect of the microcell corrosion during the HF pre treating,therefore the electrochemical properties of the alloy were improved. The changes of surface morphology and composition of the alloy resulting from the HF pre treatment are responsible for the improvement in the electrochemical properties of the alloy.
The influences of the 1%HF solution pretreatment on electrochemical properties of ZrCr0.7Ni1.3 were investigated.The results show that creak initiation and propagation and the increase of the specific surface area were accelerated due to the effect of the microcell corrosion during the HF pre treating,therefore the electrochemical properties of the alloy were improved. The changes of surface morphology and composition of the alloy resulting from the HF pre treatment are responsible for the improvement in the electrochemical properties of the alloy.
2002(4):274-278.
Abstract:
采用电化学测试技术研究了离子注氮对SUS316L不锈钢，Co-Cr合金，工业纯钛和Ti-6Al-4V植入合金在Hank’s人工模拟体液中腐蚀行为的影响。腐蚀电位和极化曲线的测量结果表明，注氮使4种植入金属材料的腐蚀电位正移，钝化电位区间扩大，耐蚀性明显提高。注氮的工业纯钛和Ti-6Al-4V合金的耐蚀性最佳，其钝化区拓宽为4V以上。通过AES分析发现，离子注氮后钛及其合金表面形成的氮化钛膜层及弥散的氮化钛析出相的化学效应，使基体电化学性能得到提高。注氮的Co-Cr合金的耐蚀性略优于SUS316L不锈钢。Co-Cr合金表面形成的钴氮化合物相对基体起到保护作用，降低了腐蚀速率。SUS316L不锈钢表面形成铁和铬氮化合物膜，有效地阻止了Cr^3 的水解，且氮离子注入促进Fe3O4的产生，提高了耐腐蚀性能。
采用电化学测试技术研究了离子注氮对SUS316L不锈钢，Co-Cr合金，工业纯钛和Ti-6Al-4V植入合金在Hank’s人工模拟体液中腐蚀行为的影响。腐蚀电位和极化曲线的测量结果表明，注氮使4种植入金属材料的腐蚀电位正移，钝化电位区间扩大，耐蚀性明显提高。注氮的工业纯钛和Ti-6Al-4V合金的耐蚀性最佳，其钝化区拓宽为4V以上。通过AES分析发现，离子注氮后钛及其合金表面形成的氮化钛膜层及弥散的氮化钛析出相的化学效应，使基体电化学性能得到提高。注氮的Co-Cr合金的耐蚀性略优于SUS316L不锈钢。Co-Cr合金表面形成的钴氮化合物相对基体起到保护作用，降低了腐蚀速率。SUS316L不锈钢表面形成铁和铬氮化合物膜，有效地阻止了Cr^3 的水解，且氮离子注入促进Fe3O4的产生，提高了耐腐蚀性能。
2002(4):279-282.
Abstract:
通过建立热力学可能反应模型，分别计算了SCS－6 SiC长纤维增强Ti3Al和TiAl金属间化合物基复合材料界面反应的Gibbs函数变值△rG，并用△rG判据推测了界面反应产物并与透射电镜实验结果进行了对比分析。研究表明，由于TiAl中原子结合力较强，因而SCS－6 SiC/TiAl复合材料的界面反应较轻。所研究的2种复合材料界面反应的二元反应产物为TiC,Ti5Si3和Ti3Si,Ti-Si相图中的其它二元硅化物不可能形成。
通过建立热力学可能反应模型，分别计算了SCS－6 SiC长纤维增强Ti3Al和TiAl金属间化合物基复合材料界面反应的Gibbs函数变值△rG，并用△rG判据推测了界面反应产物并与透射电镜实验结果进行了对比分析。研究表明，由于TiAl中原子结合力较强，因而SCS－6 SiC/TiAl复合材料的界面反应较轻。所研究的2种复合材料界面反应的二元反应产物为TiC,Ti5Si3和Ti3Si,Ti-Si相图中的其它二元硅化物不可能形成。
2002(4):283-286.
Abstract:
Specially designed SEM in situ fatigue tests have been conducted to trace the whole process of crack initiation and propagation to fracture in an Al2O3 seeded P/M Rene 95 superalloy.The results show that the loading wave shape has a strong effect on the micromechanical behavior.Under triangle wave loading crack initiation and propagation life decrease on the inclusion/matrix interface,but specimen failure is not due to the surface or sub surface inclusions.On the other hand,sine wave loading is accompanied by a significant increase the crack initiation life and surface or sub surface inclusions are always the primary cause of fatigue fracture.Furthermore,under the same loading waveform the crack initiation life increases as the amplitude of applied stress decreases.
Specially designed SEM in situ fatigue tests have been conducted to trace the whole process of crack initiation and propagation to fracture in an Al2O3 seeded P/M Rene 95 superalloy.The results show that the loading wave shape has a strong effect on the micromechanical behavior.Under triangle wave loading crack initiation and propagation life decrease on the inclusion/matrix interface,but specimen failure is not due to the surface or sub surface inclusions.On the other hand,sine wave loading is accompanied by a significant increase the crack initiation life and surface or sub surface inclusions are always the primary cause of fatigue fracture.Furthermore,under the same loading waveform the crack initiation life increases as the amplitude of applied stress decreases.
2002(4):287-290.
Abstract:
According to XRD the alloys Mn15Bi34Te51 and La15Bi34Te51 were formed after ball milling for 150 h and 100 h, respectively. Nanostructured La15Bi34Te51 resulted from extending the ball milling time to 150 h, It is suggested that the addition of La may refine the grain size and help to promote amorphism in Bi2Te3 based alloys. Further detailed XRD analysis of La15Bi34Te51 alloys suggests that the La atoms may intercalate between the Te Te layers of the Bi2Te3 layer structure. The Seeback coefficient measurements on the La15Bi34Te51 alloys indicates that the carrier scattering mechanism changes when the grain sizes are decreased to a few nanometers leading to a dramatic increase in the Seeback coefficient.
According to XRD the alloys Mn15Bi34Te51 and La15Bi34Te51 were formed after ball milling for 150 h and 100 h, respectively. Nanostructured La15Bi34Te51 resulted from extending the ball milling time to 150 h, It is suggested that the addition of La may refine the grain size and help to promote amorphism in Bi2Te3 based alloys. Further detailed XRD analysis of La15Bi34Te51 alloys suggests that the La atoms may intercalate between the Te Te layers of the Bi2Te3 layer structure. The Seeback coefficient measurements on the La15Bi34Te51 alloys indicates that the carrier scattering mechanism changes when the grain sizes are decreased to a few nanometers leading to a dramatic increase in the Seeback coefficient.
2002(4):291-294.
Abstract:
Pure and metal oxide doped nanocrystalline ceria has been prepared by the hydrothermal technique,and the samples annealed at different temperatures to study the interaction between dopants and the ceria.The results indicated that CdO enhanced the growth of ceria particles while Al2O3 and ZrO2 hindered it.MgO,CaO,SrO and BaO only hindered the ceria particle growth at lower temperatures.At higher temperatures,as the impurity phases crystallized,they no longer hindered the growth of ceria particles.
Pure and metal oxide doped nanocrystalline ceria has been prepared by the hydrothermal technique,and the samples annealed at different temperatures to study the interaction between dopants and the ceria.The results indicated that CdO enhanced the growth of ceria particles while Al2O3 and ZrO2 hindered it.MgO,CaO,SrO and BaO only hindered the ceria particle growth at lower temperatures.At higher temperatures,as the impurity phases crystallized,they no longer hindered the growth of ceria particles.
2002(4):295-298.
Abstract:
对TiAl合金涡轮的立式离心熔模陶瓷型壳精密铸造进行了研究，合金熔配设备为水冷铜坩埚真空感应熔化炉。首先研究了TiAl合金铸造时的尺寸收缩问题，结果表明1600℃浇注时，合金的收缩率为1．32％，随着浇注温度的提高凝固收缩率显著提高。从合金熔体立式离心力场下充型模式方面考虑，涡轮浇注工艺应采用类似于重力充型的底注式较好。TiAl合金涡轮离心浇注内部组织致密、无气孔，存在的主要问题是欠浇缺陷，迎流面充型较弱。可以从提高离心转速和浇注温度两方面解决欠浇缺陷，但离心转速提高带来的安全隐患以及提高浇注温度带来的粘砂问题还需进一步研究。
对TiAl合金涡轮的立式离心熔模陶瓷型壳精密铸造进行了研究，合金熔配设备为水冷铜坩埚真空感应熔化炉。首先研究了TiAl合金铸造时的尺寸收缩问题，结果表明1600℃浇注时，合金的收缩率为1．32％，随着浇注温度的提高凝固收缩率显著提高。从合金熔体立式离心力场下充型模式方面考虑，涡轮浇注工艺应采用类似于重力充型的底注式较好。TiAl合金涡轮离心浇注内部组织致密、无气孔，存在的主要问题是欠浇缺陷，迎流面充型较弱。可以从提高离心转速和浇注温度两方面解决欠浇缺陷，但离心转速提高带来的安全隐患以及提高浇注温度带来的粘砂问题还需进一步研究。
2002(4):299-302.
Abstract:
An airtight joint between high purity Al2O3 and the alloy Kovar was obtained using a partial transient liquid phase(PTLP) bonding technique with Ni Ti filler.A sandwich structure was observed in the soldered joint two side faces of the sandwich were Ti2Ni and at the center was thick layer of Ti solid solution.Shear testing indicated that the joint strength increased with increase of holding time,although a relationship between strength and joining temperature was not observed.
An airtight joint between high purity Al2O3 and the alloy Kovar was obtained using a partial transient liquid phase(PTLP) bonding technique with Ni Ti filler.A sandwich structure was observed in the soldered joint two side faces of the sandwich were Ti2Ni and at the center was thick layer of Ti solid solution.Shear testing indicated that the joint strength increased with increase of holding time,although a relationship between strength and joining temperature was not observed.
2002(4):303-307.
Abstract:
研究了WC-8%Co硬质合金的粉末注射成形工艺,考查了不同气氛和脱脂方法对脱脂坯碳含量的影响及烧结温度、保温时间对合金强度的影响,以及固体粉末装载量对产品尺寸精度及保形性的影响。结果表明:溶剂脱脂+75%N2/25%H2混合气体热脱脂工艺,不仅能大幅度提高脱脂速率,而且有利于合金碳含量的控制。提高试样固体粉末装载率有利于提高制品密度和尺寸精度。在1460℃烧结,保温2h,PIM硬质合金试样的抗弯强度、硬度、密度分别达到2480MPa,HRA900MPa,和14.72g.cm-3;烧结后制品保形性良好,尺寸偏差为±0.02mm;断口检查和金相检验没有发现任何明显缺陷,合金组织均匀;平均晶粒度为2μm,孔隙度为A02B00,无石墨夹杂和η相出现。
研究了WC-8%Co硬质合金的粉末注射成形工艺,考查了不同气氛和脱脂方法对脱脂坯碳含量的影响及烧结温度、保温时间对合金强度的影响,以及固体粉末装载量对产品尺寸精度及保形性的影响。结果表明:溶剂脱脂+75%N2/25%H2混合气体热脱脂工艺,不仅能大幅度提高脱脂速率,而且有利于合金碳含量的控制。提高试样固体粉末装载率有利于提高制品密度和尺寸精度。在1460℃烧结,保温2h,PIM硬质合金试样的抗弯强度、硬度、密度分别达到2480MPa,HRA900MPa,和14.72g.cm-3;烧结后制品保形性良好,尺寸偏差为±0.02mm;断口检查和金相检验没有发现任何明显缺陷,合金组织均匀;平均晶粒度为2μm,孔隙度为A02B00,无石墨夹杂和η相出现。
2002(4):308-311.
Abstract:
采用微弧氧化对钛合金表面改性，讨论在不同条件下微弧氧化膜的形貌、结构和成份。结果表明，在钛合金表面得到一层金红石型TiO2和锐钛矿型TiO2的多孔氧化膜，且在膜中可以渗入钙，磷离子。膜层中的元素呈阶梯分布，外层的Ca,P含量较大，Ca/P含量随溶液中Ca/P含量近似呈线性增强。在确定的电解液下表面孔隙率基本不变，但孔洞大小随反应电压的增加而增加；膜的生长速率随反应时间的延长呈先快后慢变化。这种含有Ca，P成份的多孔表层结构有利于骨细胞的吸附和结合。
采用微弧氧化对钛合金表面改性，讨论在不同条件下微弧氧化膜的形貌、结构和成份。结果表明，在钛合金表面得到一层金红石型TiO2和锐钛矿型TiO2的多孔氧化膜，且在膜中可以渗入钙，磷离子。膜层中的元素呈阶梯分布，外层的Ca,P含量较大，Ca/P含量随溶液中Ca/P含量近似呈线性增强。在确定的电解液下表面孔隙率基本不变，但孔洞大小随反应电压的增加而增加；膜的生长速率随反应时间的延长呈先快后慢变化。这种含有Ca，P成份的多孔表层结构有利于骨细胞的吸附和结合。
2002(4):312-314.
Abstract:
Nanocrystalline CeO2 was prepared by hydrothermal crystallization method. XRD analysis indicates that the structure of the synthesized CeO2 is cubic with space group O5H FM3M. TEM photos reveals that nanocrystalline CeO2 is spherical in shape with a mean particle size of less than 100 nm. It was found that with increase of hydrothermal treatment temperatures the relative density of CeO2 nanocrystalline increased.
Nanocrystalline CeO2 was prepared by hydrothermal crystallization method. XRD analysis indicates that the structure of the synthesized CeO2 is cubic with space group O5H FM3M. TEM photos reveals that nanocrystalline CeO2 is spherical in shape with a mean particle size of less than 100 nm. It was found that with increase of hydrothermal treatment temperatures the relative density of CeO2 nanocrystalline increased.
2002(4):315-318.
Abstract:
在研究了贵金属Pd和离子Pd2+催化剂对纳米结构厚膜材料气敏特性的影响之后,提出了纳米催化效应的见解。认为将微量Pd2+的水溶液加入到纳米晶SnO2-x粉体中,可使Pd2+离子均匀地分布。所形成的PdO1-x纳米晶,能更均匀地存在于纳米结构厚膜材料载体中,有望对可燃性气体起到最有效的纳米催化作用。实验结果表明当Pd2+离子最佳的引入量为1.04mol%时,对3000×10-6甲烷的灵敏度可达9～11。
在研究了贵金属Pd和离子Pd2+催化剂对纳米结构厚膜材料气敏特性的影响之后,提出了纳米催化效应的见解。认为将微量Pd2+的水溶液加入到纳米晶SnO2-x粉体中,可使Pd2+离子均匀地分布。所形成的PdO1-x纳米晶,能更均匀地存在于纳米结构厚膜材料载体中,有望对可燃性气体起到最有效的纳米催化作用。实验结果表明当Pd2+离子最佳的引入量为1.04mol%时,对3000×10-6甲烷的灵敏度可达9～11。
2002(4):319-319.
Abstract:
选取平均粒度为２．０μm的W粉末，小于４８μm的羰基Ni粉末和小于７４μm的羰基Fe粉末，纯度大于９９％。按照９０W－７Ni－３Fe配成合金粉末。先期投入４９％Ni，２１％Fe以及３０％的W粉末（均质量分数）球磨８h后，再加入余量的W粉末球磨至２２h，球料比为４∶１，停机后在真空中干燥。利用冷等静压成型得到７mm×６０mm的试样棒。将试样棒埋在Al２O３粉中，置于空气烧结炉中加热至４５０℃，经过３０min的保温预氧化后，再经不同温度在氨分解的氢气氛（低于－２０℃的露点）中烧结，最后以５０℃／min的速率冷却到室温，为进一…
选取平均粒度为２．０μm的W粉末，小于４８μm的羰基Ni粉末和小于７４μm的羰基Fe粉末，纯度大于９９％。按照９０W－７Ni－３Fe配成合金粉末。先期投入４９％Ni，２１％Fe以及３０％的W粉末（均质量分数）球磨８h后，再加入余量的W粉末球磨至２２h，球料比为４∶１，停机后在真空中干燥。利用冷等静压成型得到７mm×６０mm的试样棒。将试样棒埋在Al２O３粉中，置于空气烧结炉中加热至４５０℃，经过３０min的保温预氧化后，再经不同温度在氨分解的氢气氛（低于－２０℃的露点）中烧结，最后以５０℃／min的速率冷却到室温，为进一…
