Volume 0,Issue 6,1999 Table of Contents
1999(6).
Abstract:
Biaxial low cycle fatigue properties of the alloy Zr-4 have been studied for the principal strain ratios (ε3／ε1) of -0.8，-0.7，-0.6，-0.5 and the equivalent strain ranges of 0.5%，0.7%，0.8%，0.9%，1.0%，1.1%.The results show that the al
Biaxial low cycle fatigue properties of the alloy Zr-4 have been studied for the principal strain ratios (ε3／ε1) of -0.8，-0.7，-0.6，-0.5 and the equivalent strain ranges of 0.5%，0.7%，0.8%，0.9%，1.0%，1.1%.The results show that the al
1999(6).
Abstract:
The microstructure of a monolithic Ll2 Al67Mn8Ti25 compound changes significantly when modified with a small amount of Nb (0.2～4.0at%) and with corresponding adjustments to the Ti and Al contents. In 32 exper
The microstructure of a monolithic Ll2 Al67Mn8Ti25 compound changes significantly when modified with a small amount of Nb (0.2～4.0at%) and with corresponding adjustments to the Ti and Al contents. In 32 exper
1999(6):1.
Abstract:
Effect of pellet diameter on the combustion velocity and temperature profile in the combustion synthesis of Al2O3-TiC ceramics and microstructure change in the radial direction of the cylindrical products were investigated. For a
Effect of pellet diameter on the combustion velocity and temperature profile in the combustion synthesis of Al2O3-TiC ceramics and microstructure change in the radial direction of the cylindrical products were investigated. For a
1999(6):4.
Abstract:
The LaNi5 alloy is a typical hydrogen-storage material. On the basis of the empirical electron theory of solids and molecules(EET), the valence electron structures of the LaNi5 alloy and bond energies of main bonds between upper strata and lower strata for substitution of Co andor Mn for partial Ni in the LaNi5 alloy are calculated. The results indicate that these bond energies increase when Mn is subslituted for Ni2, or Co is substituted for Ni1 or Ni2. When both Mn and Ni are substituted for Ni, the bond energies increase greatly. as a result of which the lifetime of the LaNi5 alloy increases.
The LaNi5 alloy is a typical hydrogen-storage material. On the basis of the empirical electron theory of solids and molecules(EET), the valence electron structures of the LaNi5 alloy and bond energies of main bonds between upper strata and lower strata for substitution of Co andor Mn for partial Ni in the LaNi5 alloy are calculated. The results indicate that these bond energies increase when Mn is subslituted for Ni2, or Co is substituted for Ni1 or Ni2. When both Mn and Ni are substituted for Ni, the bond energies increase greatly. as a result of which the lifetime of the LaNi5 alloy increases.
1999(6):345-348.
Abstract:
测量了再结晶态Ｔａ－１２Ｗ合金板的室温至１６００℃的拉伸性能。在室温下拉伸，Ｔａ－１２Ｗ合金展示出良好的固溶强化和优良的延性。提高试验温度，合金的强度和延性均逐渐下降。
测量了再结晶态Ｔａ－１２Ｗ合金板的室温至１６００℃的拉伸性能。在室温下拉伸，Ｔａ－１２Ｗ合金展示出良好的固溶强化和优良的延性。提高试验温度，合金的强度和延性均逐渐下降。
1999(6):349-352.
Abstract:
研究了Zr-4合金管材在主应变比ε3／ε1=-0.8，-0．7，-0．6，-0．5和等效应变幅0．5％，0．7％，0．8％，0．9％，1．0％，1．1％下的低周多轴疲劳性能。结果表明：在拉-扭比例加载过程中，再结晶状态Zr－4合金表现为初期短暂硬化，随后持续软化的特性。Zr－4合金的循环等效应力-应变曲线位于单调曲线的上方，表现为循环硬化。主应变化对循环硬化曲线没有影响。相同Mises等效应变幅下，应变比越大，疲劳寿命越低。双轴疲劳过程中，Zr－4合金Mises等效应变幅与疲劳寿命之间呈指数关系。
研究了Zr-4合金管材在主应变比ε3／ε1=-0.8，-0．7，-0．6，-0．5和等效应变幅0．5％，0．7％，0．8％，0．9％，1．0％，1．1％下的低周多轴疲劳性能。结果表明：在拉-扭比例加载过程中，再结晶状态Zr－4合金表现为初期短暂硬化，随后持续软化的特性。Zr－4合金的循环等效应力-应变曲线位于单调曲线的上方，表现为循环硬化。主应变化对循环硬化曲线没有影响。相同Mises等效应变幅下，应变比越大，疲劳寿命越低。双轴疲劳过程中，Zr－4合金Mises等效应变幅与疲劳寿命之间呈指数关系。
1999(6):357-362.
Abstract:
研究了ＤＺ４０Ｍ钴基合金低压气相沉积简单铝化物和钛改性铝化物２种涂层的形成及其高温氧化时的相变退化过程。
研究了ＤＺ４０Ｍ钴基合金低压气相沉积简单铝化物和钛改性铝化物２种涂层的形成及其高温氧化时的相变退化过程。
1999(6):363-367.
Abstract:
研究了压坯直径对燃烧合成Al2O3－TiC陶瓷的燃烧速度和温度的影响以及圆柱试样的径向微观组织变化。燃烧合成的圆柱试样轴心区直径1．5μm～5.5μm的圆形颗粒为TiC，具有熔化特征的边长10μm～20μm的多边形为含有少量TiC的刚玉；在二分之一半径处，TiC颗粒和刚玉块的尺寸分别减小为0．1μm～3μm和5μm～15μm；但在靠近合成试样圆周及其圆柱表面，刚玉变成为了晶须，TiC则是0．1μm－0．5μm的微小颗粒组成的团聚体。这是因为试样在燃烧合成过程中沿周向和径向均有热量传递，燃烧过程中径向不同位
研究了压坯直径对燃烧合成Al2O3－TiC陶瓷的燃烧速度和温度的影响以及圆柱试样的径向微观组织变化。燃烧合成的圆柱试样轴心区直径1．5μm～5.5μm的圆形颗粒为TiC，具有熔化特征的边长10μm～20μm的多边形为含有少量TiC的刚玉；在二分之一半径处，TiC颗粒和刚玉块的尺寸分别减小为0．1μm～3μm和5μm～15μm；但在靠近合成试样圆周及其圆柱表面，刚玉变成为了晶须，TiC则是0．1μm－0．5μm的微小颗粒组成的团聚体。这是因为试样在燃烧合成过程中沿周向和径向均有热量传递，燃烧过程中径向不同位
1999(6):368-370.
Abstract:
The LaNi5 alloy is a typical hydrogen-storage material. On the basis of the empirical electron theory of solids andmolecules (EET), the valence electron structures of the LaNi5 alloy and bond energies of main bonds between upper strata andlower strata for substitution of Co andor Mn for partial Ni in the LaNi5 alloy are calculated. The results indicate that these bondenergies increase when Mn is subslituted for Ni2, or Co is substituted for Ni, or Ni2. When both Mn and Ni are substituted forNi, the bond energies increase greatly. as a result of which the lifetime of the LaNi5 alloy increases.
The LaNi5 alloy is a typical hydrogen-storage material. On the basis of the empirical electron theory of solids andmolecules (EET), the valence electron structures of the LaNi5 alloy and bond energies of main bonds between upper strata andlower strata for substitution of Co andor Mn for partial Ni in the LaNi5 alloy are calculated. The results indicate that these bondenergies increase when Mn is subslituted for Ni2, or Co is substituted for Ni, or Ni2. When both Mn and Ni are substituted forNi, the bond energies increase greatly. as a result of which the lifetime of the LaNi5 alloy increases.
1999(6):375-379.
Abstract:
The microstructure of a monolithic Ll2Al67Mn8Ti25, compound changes significantly when modified with a small amount ofNb (0. 2~4. 0at%) and with corresponding adjustments to the Ti and Al contents. In 32 experimental alloys near the Al3Ti-8Mncomposition region of the Al-Ti-8Mn-Nb quaternary system, five multiphase regions. Ll2+Al2Ti, Ll2+DO22, Ll2+Ll0, Ll2,+Al2Ti+DO22 and Ll2+Al2Ti+Ll0 formed adjacent to the original Ll2 single phase. When Nb content keeps constant, the plate-like or nettyAl2Ti phase precipitates appear with the decrease of Al/Ti ratio. The ripple-like Ll0 AlTi phase may appear in the alloys containedhigher Nb c0ntents. A room temperature constitutional diagram near the Al3Ti-8Mn region of Al-Ti-Nb-8Mn quaternary system hasbeen determined.
The microstructure of a monolithic Ll2Al67Mn8Ti25, compound changes significantly when modified with a small amount ofNb (0. 2~4. 0at%) and with corresponding adjustments to the Ti and Al contents. In 32 experimental alloys near the Al3Ti-8Mncomposition region of the Al-Ti-8Mn-Nb quaternary system, five multiphase regions. Ll2+Al2Ti, Ll2+DO22, Ll2+Ll0, Ll2,+Al2Ti+DO22 and Ll2+Al2Ti+Ll0 formed adjacent to the original Ll2 single phase. When Nb content keeps constant, the plate-like or nettyAl2Ti phase precipitates appear with the decrease of Al/Ti ratio. The ripple-like Ll0 AlTi phase may appear in the alloys containedhigher Nb c0ntents. A room temperature constitutional diagram near the Al3Ti-8Mn region of Al-Ti-Nb-8Mn quaternary system hasbeen determined.
1999(6):380-382.
Abstract:
对不同表面状态的Ｚｒ－４管材在５００℃，１０．３ＭＰａ下的过热蒸汽中进行了腐蚀试验。实验证明：表面处理状态对合金抗疖状腐蚀性能有较大影响。经酸洗后可提高抗疖状腐蚀性能，预生氧化膜处理可起到延缓疖状腐蚀的作用。结果表明，酸洗后预膜处理的表面有最好的抗疖状腐蚀性能。
对不同表面状态的Ｚｒ－４管材在５００℃，１０．３ＭＰａ下的过热蒸汽中进行了腐蚀试验。实验证明：表面处理状态对合金抗疖状腐蚀性能有较大影响。经酸洗后可提高抗疖状腐蚀性能，预生氧化膜处理可起到延缓疖状腐蚀的作用。结果表明，酸洗后预膜处理的表面有最好的抗疖状腐蚀性能。
1999(6):383-385.
Abstract:
The composition of a machineable glass ceramic containing ZrO2 was optimized using machineability testing. The effects ofK2O, CaO, MgO and Al2O3 on the machineablity of the glass ceramic were studied and the results analyzed in terms of the relationship between crystallization 0f a mica phase and composition of the bulk. The XRD result shows that the glass ceramic after optimization contains a large amount of tetragonal ZrO2 and mica phases.
The composition of a machineable glass ceramic containing ZrO2 was optimized using machineability testing. The effects ofK2O, CaO, MgO and Al2O3 on the machineablity of the glass ceramic were studied and the results analyzed in terms of the relationship between crystallization 0f a mica phase and composition of the bulk. The XRD result shows that the glass ceramic after optimization contains a large amount of tetragonal ZrO2 and mica phases.
1999(6):386-389.
Abstract:
Impact attrition is an advanced technique for the production of bery1lium powder. As compared with discattrited powder, it has many advantages: narrow range of particle distribution, near-spherical particle shape and lower oxygen content. Themechanical properties and isotropy of the resulting hot-pressed or isostatic-pressed compacts are in general improved.
Impact attrition is an advanced technique for the production of bery1lium powder. As compared with discattrited powder, it has many advantages: narrow range of particle distribution, near-spherical particle shape and lower oxygen content. Themechanical properties and isotropy of the resulting hot-pressed or isostatic-pressed compacts are in general improved.
14 Evaluation of the Control Mode of Al Element Evaporation During ISM Process of Ti-Al Intermetallics
1999(6):390-394.
Abstract:
On the basis of an in-depth analysis of the evaporation process of alloying elements during induction skull melting (ISM) amodel for the control mode of element evaporation has been established. The calculated results of Al element evaporation in Ti-48Al-2Cr-2Nb (at%) and Ti-24Al-11Nb (at%) alloys show that when melt temperature increases and/or pressure decreases, the controlmode of Al element evaporation changes from an evaporating reaction control mode at low melt temperature and/or under high outerpressure to a double control mode-evaporating reaction and liquid phase diffusion at high melt temperature and/or under low pressure. When the outer pressure is 133.3 Pa, the transformation temperatures of the control mode of Al element evaporation are approximately 1950 K and 2000 K respectively for the Ti-48Al-2Cr-2Nb (at%) and Ti-24Al-11Nb (at%) alloys. While the transformation pressures of the same alloys are approximately 133. 3 Pa and 66 Pa respectively when the melt temperature is 2073 K. Thereason is that the saturated vapor pressures of Al element in various alloys are different.
On the basis of an in-depth analysis of the evaporation process of alloying elements during induction skull melting (ISM) amodel for the control mode of element evaporation has been established. The calculated results of Al element evaporation in Ti-48Al-2Cr-2Nb (at%) and Ti-24Al-11Nb (at%) alloys show that when melt temperature increases and/or pressure decreases, the controlmode of Al element evaporation changes from an evaporating reaction control mode at low melt temperature and/or under high outerpressure to a double control mode-evaporating reaction and liquid phase diffusion at high melt temperature and/or under low pressure. When the outer pressure is 133.3 Pa, the transformation temperatures of the control mode of Al element evaporation are approximately 1950 K and 2000 K respectively for the Ti-48Al-2Cr-2Nb (at%) and Ti-24Al-11Nb (at%) alloys. While the transformation pressures of the same alloys are approximately 133. 3 Pa and 66 Pa respectively when the melt temperature is 2073 K. Thereason is that the saturated vapor pressures of Al element in various alloys are different.
1999(6):398-400.
Abstract:
A new manufacturing method for special gold matrix three-ply composites microtape is presented, and compared withcommon methods which have been employed elsewhere in the world. The new method utilizes the techniques of:explosion composite-forming, diffusion welding (or brazing),groove rolling,special die drawing and finish rolling using 12-roll micromill.
A new manufacturing method for special gold matrix three-ply composites microtape is presented, and compared withcommon methods which have been employed elsewhere in the world. The new method utilizes the techniques of:explosion composite-forming, diffusion welding (or brazing),groove rolling,special die drawing and finish rolling using 12-roll micromill.
1999(6):406-409.
Abstract:
The determination of fracture toughness of brittle materials is often conducted using three-point bend beam method, in which the initiating crack is usually in the form of a diamond-sawed notch. In this paper a model of the fracture process is proposed. The model can be used to predict the fracture toughness from the apparent toughness and microstructural parameters, where the apparent toughness is measured using the sawed-notch crack method. The dependence of KIC on the notch root radius was examined in two kinds of polycrystalline alumina and one soda-lime glass for notch radii as small as a few micrometers, The results show that when the notch radius is near to or smaller than the average grain diameter, the toughness is almost constant. When the critical notch radius used for determining toughness is approximately equal to the average grain diameter, a true measure of fracture toughness can be obtained.
The determination of fracture toughness of brittle materials is often conducted using three-point bend beam method, in which the initiating crack is usually in the form of a diamond-sawed notch. In this paper a model of the fracture process is proposed. The model can be used to predict the fracture toughness from the apparent toughness and microstructural parameters, where the apparent toughness is measured using the sawed-notch crack method. The dependence of KIC on the notch root radius was examined in two kinds of polycrystalline alumina and one soda-lime glass for notch radii as small as a few micrometers, The results show that when the notch radius is near to or smaller than the average grain diameter, the toughness is almost constant. When the critical notch radius used for determining toughness is approximately equal to the average grain diameter, a true measure of fracture toughness can be obtained.
