Volume 0,Issue 4,1999 Table of Contents
1999(4):1-221.
Abstract:
研究了铝合金表面激光熔覆Fe-Al青铜层的组织结构，结果表明，熔覆层的组织结构为孪晶结构的α-Cu+颗粒状(Cu, Fe, Si)
研究了铝合金表面激光熔覆Fe-Al青铜层的组织结构，结果表明，熔覆层的组织结构为孪晶结构的α-Cu+颗粒状(Cu, Fe, Si)
1999(4):1.
Abstract:
实验结果表明，较慢的熔化生长速度有利于改善YBCO晶体的形貌并提高其磁悬浮性能。但无论怎样改善工艺都很难得到单畴的YBCO大块超导材料。为此引进了Sm
实验结果表明，较慢的熔化生长速度有利于改善YBCO晶体的形貌并提高其磁悬浮性能。但无论怎样改善工艺都很难得到单畴的YBCO大块超导材料。为此引进了Sm
1999(4):198-201.
Abstract:
The formation and transformation in (Bi,Pb) 2Sr 2CaCu 2O x have been studied from the point of view of growth kinetics. The component, reaction products and microstructures were analyzed by differential thermal analysis (DTA), XRD, SEM and energy dispersive x ray analysis(ED). The results show that the formation process of (Bi,Pb) 2212 phase follows the rules of solid reaction kinetics. For the formation of textured (Bi,Pb) 2212 phase it is advantageous to choose a very high degree of supercooling and relatively long heat treatment time.
The formation and transformation in (Bi,Pb) 2Sr 2CaCu 2O x have been studied from the point of view of growth kinetics. The component, reaction products and microstructures were analyzed by differential thermal analysis (DTA), XRD, SEM and energy dispersive x ray analysis(ED). The results show that the formation process of (Bi,Pb) 2212 phase follows the rules of solid reaction kinetics. For the formation of textured (Bi,Pb) 2212 phase it is advantageous to choose a very high degree of supercooling and relatively long heat treatment time.
1999(4):202-205.
Abstract:
采用Ｘ射线粉末衍射和Ｒｉｅｔｖｅｌｄ全谱拟事分析，详细地研究了Ｚｒ（Ｍｎ１－ｘＮｉｘ）２（ｘ＝０．４０～０．７５）三元Ｌａｖｅｓ相贮氢合金中形成Ｚｒ－Ｎｉ相的类型及其晶体结构。实验结果表明：Ｚｒ－Ｍｎ－Ｎｉ合金中出现的Ｚ４－Ｍｎ－Ｎｉ合金中出现的Ｚｒ－Ｎｉ相包括ＺｒＮｉ、Ｚｒ９Ｎｉ１１和Ｚｒ７Ｎｉ１０３类，ｒ－Ｎｉ相类型与合金中的Ｎｉ含量有关。其中，ＺｒＮｉ相在ｘ＝０．４０～０．５０范围内出现，Ｚ
采用Ｘ射线粉末衍射和Ｒｉｅｔｖｅｌｄ全谱拟事分析，详细地研究了Ｚｒ（Ｍｎ１－ｘＮｉｘ）２（ｘ＝０．４０～０．７５）三元Ｌａｖｅｓ相贮氢合金中形成Ｚｒ－Ｎｉ相的类型及其晶体结构。实验结果表明：Ｚｒ－Ｍｎ－Ｎｉ合金中出现的Ｚ４－Ｍｎ－Ｎｉ合金中出现的Ｚｒ－Ｎｉ相包括ＺｒＮｉ、Ｚｒ９Ｎｉ１１和Ｚｒ７Ｎｉ１０３类，ｒ－Ｎｉ相类型与合金中的Ｎｉ含量有关。其中，ＺｒＮｉ相在ｘ＝０．４０～０．５０范围内出现，Ｚ
1999(4):206-209.
Abstract:
A new predicting methodology for the time temperature transformation diagrams of medium carbon multicomponent alloy steels is proposed. Some critical transformation points used to model the time temperature transformation diagrams of multicomponent alloy steels are given as a function of alloy chemistry. It has been found that the bay between two C curves(pearlite and bainite) can be predicted correctly in terms of a precisely calculated B s temperature. The commercial application potential of this approach to the design of new multicomponent alloy steels is also discussed in detail
A new predicting methodology for the time temperature transformation diagrams of medium carbon multicomponent alloy steels is proposed. Some critical transformation points used to model the time temperature transformation diagrams of multicomponent alloy steels are given as a function of alloy chemistry. It has been found that the bay between two C curves(pearlite and bainite) can be predicted correctly in terms of a precisely calculated B s temperature. The commercial application potential of this approach to the design of new multicomponent alloy steels is also discussed in detail
1999(4):214-217.
Abstract:
研究了锆金管材中氢化物的生长方式。结果表明：氢化物片（条）是在晶界上生长，并且以尖端延伸的方式向前发展。氢化物片的厚度近似一常数值，与氢含量（渗氢量）没有对应关系。氢含量的增加只增加化物片的数量。同时分析了造成氢化物这种生长方式的原因。
研究了锆金管材中氢化物的生长方式。结果表明：氢化物片（条）是在晶界上生长，并且以尖端延伸的方式向前发展。氢化物片的厚度近似一常数值，与氢含量（渗氢量）没有对应关系。氢含量的增加只增加化物片的数量。同时分析了造成氢化物这种生长方式的原因。
1999(4):222-224.
Abstract:
应用三元扩散偶技术测定Ｎｉ－Ｒｅ－Ｔａ三元系１４７３Ｋ的等温截面。用电子探针微区成分分析方法对Ｎｉ－Ｒｅ－Ｔａ三元扩散偶进行是得Ｎｉ－Ｒｅ－Ｔａ三元系在１４７３Ｋ下生成ｉ３Ｔａ、Ｎｉ２Ｔａ、ＮｉＴａ、ＮＩＴａ２和ｘ相５个扩散层，在扩散 未发现三元化合物。
应用三元扩散偶技术测定Ｎｉ－Ｒｅ－Ｔａ三元系１４７３Ｋ的等温截面。用电子探针微区成分分析方法对Ｎｉ－Ｒｅ－Ｔａ三元扩散偶进行是得Ｎｉ－Ｒｅ－Ｔａ三元系在１４７３Ｋ下生成ｉ３Ｔａ、Ｎｉ２Ｔａ、ＮｉＴａ、ＮＩＴａ２和ｘ相５个扩散层，在扩散 未发现三元化合物。
1999(4):225-227.
Abstract:
The relation of fracture lifetime to stress and temperature has been investigated for two low carbon manganese steels in air and H 2S, The influence of hydrogen on the fracture activation energy is studied. The results show that hydrogen reduces the fracture activation energy by 74%, that is, atomic binding force decreases.
The relation of fracture lifetime to stress and temperature has been investigated for two low carbon manganese steels in air and H 2S, The influence of hydrogen on the fracture activation energy is studied. The results show that hydrogen reduces the fracture activation energy by 74%, that is, atomic binding force decreases.
1999(4):236-239.
Abstract:
The distribution of T 1 precipitates at the subgrain boundaries and the nucleation of secondary precipitates in the alloy aluminum lithium 2090 have been studied using TEM. The results show that the aspect ratios of the T 1 phase particles which precipitate at the subgrain boundaries is similar to or even smaller than those of nearby T 1 phases, indicating limited coarsening of the T 1 phase. It is calculated that this result conforms to the Perovic criterion, i.e. that it is necessary to balance the elastic interaction energy among the T 1 precipitates in order to stabilize the distribution of the T 1 precipitates. Small T 1 precipitates always appear at the intersection between existing T 1 phases where the nucleation energy of the T 1 phase is lower
The distribution of T 1 precipitates at the subgrain boundaries and the nucleation of secondary precipitates in the alloy aluminum lithium 2090 have been studied using TEM. The results show that the aspect ratios of the T 1 phase particles which precipitate at the subgrain boundaries is similar to or even smaller than those of nearby T 1 phases, indicating limited coarsening of the T 1 phase. It is calculated that this result conforms to the Perovic criterion, i.e. that it is necessary to balance the elastic interaction energy among the T 1 precipitates in order to stabilize the distribution of the T 1 precipitates. Small T 1 precipitates always appear at the intersection between existing T 1 phases where the nucleation energy of the T 1 phase is lower
1999(4):240-243.
Abstract:
The rolling process in the 4 roll MK 150/250 cold rolling mill is discussed and analysised. Considered are the pass schedule and the design of the assistant guide plate for Ti bars, ideal square, rectangular and round Ti bars have been obtained. Based on experimental results and theoretical analysis, the influence of rolling load on the tensile strength and elongation of the bars is discussed in detail.
The rolling process in the 4 roll MK 150/250 cold rolling mill is discussed and analysised. Considered are the pass schedule and the design of the assistant guide plate for Ti bars, ideal square, rectangular and round Ti bars have been obtained. Based on experimental results and theoretical analysis, the influence of rolling load on the tensile strength and elongation of the bars is discussed in detail.
11 Investigation of the DC Voltage Current Characteristic of Nano sized TiO 2 with an Anatase Structure
1999(4):244-247.
Abstract:
The effects of formation pressure, sintering and measurement conditions (in air or in vacuum) on electrical conductivity are studied by means of the measurements of DC voltage current characteristic. Experimental results are explained using the double depletion layer model.
The effects of formation pressure, sintering and measurement conditions (in air or in vacuum) on electrical conductivity are studied by means of the measurements of DC voltage current characteristic. Experimental results are explained using the double depletion layer model.
Xie Kun
,
Wang Jiannong
,
Tang Jiancheng
,
Luo Cheng
,
Zhang Junhong
,
He Yuehui
,
Huong Baiyun $$$$
1999(4):248-251.
Abstract:
探讨了循环热处理技术在细化ＴｉＡｌ合金晶粒方面的应用。研究表明，粗大的铸态组织）约５００μｍ的全层状组织）经块型转变预处理后，在α转变温度进行６次以上的快速加热－冷却处理，可以显著地细化晶粒。由此还可以制备出２０μｍ的细小全层状组织。晶粒细化的原因是进行快速循环相变破坏了组织跗以及新旧闰向关系。影响细化效果的主要因素有；加热速度、保温时间、冷却速度和循环次数。
探讨了循环热处理技术在细化ＴｉＡｌ合金晶粒方面的应用。研究表明，粗大的铸态组织）约５００μｍ的全层状组织）经块型转变预处理后，在α转变温度进行６次以上的快速加热－冷却处理，可以显著地细化晶粒。由此还可以制备出２０μｍ的细小全层状组织。晶粒细化的原因是进行快速循环相变破坏了组织跗以及新旧闰向关系。影响细化效果的主要因素有；加热速度、保温时间、冷却速度和循环次数。
1999(4):252-255.
Abstract:
The distribution and function of rare earths in a rare earth silver alloy have been studied by means of metallographic examination, electron probe microanalysis and hardness measurement. It has been found that the rare earth compounds distribute in the dendrite grain boundaries of the cast silver alloy. The rare earth compounds congregated in the grain boundaries remarkably result in pronounced grain boundary strengthening, and small amount of rare earth compounds within the grains play a role in solution strengthening. The crushed rare earth compounds in the strong deformed silver alloy lead to a cluster structure after annealing. "Double rare earths", i.e. a pair of similar rare earth elements distribute themselves in similar ways within the silver alloy. If the natures of two rare earth elements are different from each other, their functions are complementary, and the performance of the silver alloy is improved. The addition of yttrium to silver improves work hardenability and high temperature oxidation resistance; further improvement is obtained when yttrium and light rare earth elements are added together.
The distribution and function of rare earths in a rare earth silver alloy have been studied by means of metallographic examination, electron probe microanalysis and hardness measurement. It has been found that the rare earth compounds distribute in the dendrite grain boundaries of the cast silver alloy. The rare earth compounds congregated in the grain boundaries remarkably result in pronounced grain boundary strengthening, and small amount of rare earth compounds within the grains play a role in solution strengthening. The crushed rare earth compounds in the strong deformed silver alloy lead to a cluster structure after annealing. "Double rare earths", i.e. a pair of similar rare earth elements distribute themselves in similar ways within the silver alloy. If the natures of two rare earth elements are different from each other, their functions are complementary, and the performance of the silver alloy is improved. The addition of yttrium to silver improves work hardenability and high temperature oxidation resistance; further improvement is obtained when yttrium and light rare earth elements are added together.
1999(4):260-263.
Abstract:
It is difficult to manufacture metal foams using electrical resistivity as a control parameter and due to problems associated with simultaneous production and resistivity measurement. In this paper, some new theoretical formulas to describe the resistivity of highly porous metals are established. An approach is presented for calculation of the electrical resistivity of high porous metal foams as a function of porosity, This simple and convenient method enables the design of porous materials and the control of the electrical resistivity of metal foams.
It is difficult to manufacture metal foams using electrical resistivity as a control parameter and due to problems associated with simultaneous production and resistivity measurement. In this paper, some new theoretical formulas to describe the resistivity of highly porous metals are established. An approach is presented for calculation of the electrical resistivity of high porous metal foams as a function of porosity, This simple and convenient method enables the design of porous materials and the control of the electrical resistivity of metal foams.
