Volume 0,Issue 6,1998 Table of Contents
Xi Zhengping
,
Zhou Lian
,
Li Jian
,
Liao Jichang
,
Wu Lujian
,
Li Yalu
,
Li Jianping
,
Zhang Yanrong
1998(6):317-321.
Abstract:
The current status of development, fundamental characteristics, and applications of metal fibres are discussed. It is found that many new types of material have been developed by using metal fibres,and that these materials have direct impact on the human daily life. Progress in metal fibre research and fibre products in China are described. China has a considerable competitive advantage in research and development of metal fibres and fibre products. There is a fairly good technical bases for predicting significant advances in the industrialization of metal fibres and fibre products in China.
The current status of development, fundamental characteristics, and applications of metal fibres are discussed. It is found that many new types of material have been developed by using metal fibres,and that these materials have direct impact on the human daily life. Progress in metal fibre research and fibre products in China are described. China has a considerable competitive advantage in research and development of metal fibres and fibre products. There is a fairly good technical bases for predicting significant advances in the industrialization of metal fibres and fibre products in China.
1998(6):322-326.
Abstract:
The Ti-Ni-Nb shape memory alloy possesses a wide transformation hysteresis and excellent shape memory properties, so that it is expected to be used for pipe couplings and mechanical fasteners. The engineering significance of widening hysteresis is discussed. Recent advances in the study of this alloy are reviewed, including microstructure, martenstic transformation, mechanical behavior, strain recovery ratio, low temperature thermal capacity and machinability, etc. Future development of this alloy is also discussed.
The Ti-Ni-Nb shape memory alloy possesses a wide transformation hysteresis and excellent shape memory properties, so that it is expected to be used for pipe couplings and mechanical fasteners. The engineering significance of widening hysteresis is discussed. Recent advances in the study of this alloy are reviewed, including microstructure, martenstic transformation, mechanical behavior, strain recovery ratio, low temperature thermal capacity and machinability, etc. Future development of this alloy is also discussed.
1998(6):331-335.
Abstract:
By means of the Empirical Electron Theory (E E T), the valence electron structures of ordered and disordered TiAl at various temperatures are calculated. The effect of crystal lattice expansion and decrease of long -and short-rang order parameter (with increasing temperature) on strengthening is analyzed. The reason of an anomalous yield behavior in TiAl is that the valence electron structures directly effected by temperature result in strengthening, and "disorder domain" strengthening (with short order -range parameter descending). According to this view point, an mechanism is proposed, and some experimental results that content and grain size have influence on anomalous yield behavior in TiAl are explained.
By means of the Empirical Electron Theory (E E T), the valence electron structures of ordered and disordered TiAl at various temperatures are calculated. The effect of crystal lattice expansion and decrease of long -and short-rang order parameter (with increasing temperature) on strengthening is analyzed. The reason of an anomalous yield behavior in TiAl is that the valence electron structures directly effected by temperature result in strengthening, and "disorder domain" strengthening (with short order -range parameter descending). According to this view point, an mechanism is proposed, and some experimental results that content and grain size have influence on anomalous yield behavior in TiAl are explained.
1998(6):336-339.
Abstract:
采用金相显微镜，扫描电镜和透射电镜，对超塑性拉伸变形后的Ｔｉ－１１Ａｌ－３Ｃｒ－０．５Ｍｏ（质量分数）合金的显微组织进行了观察和分析。研究发现，ＴｉＡｌ基合金在超塑性变形过程中发生了动态再结晶现象，动态再结晶使晶粒显著细化。透射电镜观察结果表明，γ晶粒内有位错运动，位错运动导致γ晶粒内形成位错墙，位错网。这些显微组织特征与ＴｉＡｌ基合金的超塑性变形机理有着密切的关系。
采用金相显微镜，扫描电镜和透射电镜，对超塑性拉伸变形后的Ｔｉ－１１Ａｌ－３Ｃｒ－０．５Ｍｏ（质量分数）合金的显微组织进行了观察和分析。研究发现，ＴｉＡｌ基合金在超塑性变形过程中发生了动态再结晶现象，动态再结晶使晶粒显著细化。透射电镜观察结果表明，γ晶粒内有位错运动，位错运动导致γ晶粒内形成位错墙，位错网。这些显微组织特征与ＴｉＡｌ基合金的超塑性变形机理有着密切的关系。
1998(6):340-343.
Abstract:
研究了定向凝固钴基高温合金ＤＺ４０Ｍ７００℃和９００℃缺口疲劳性能有疲劳断口。结果表明，ＤＺ４０Ｍ合金具有较高的抗高温缺口疲劳破坏能力，７００℃和９００℃缺口疲劳强度分别为２８５ＭＰａ和２０３ＭＰａ，且表现出低的疲劳缺口敏感性，７００℃和９００℃疲劳缺口敏感度仅为０．１４６和．１５３。在交变载茶作用下，７００℃缺口疲劳裂纹是以小平面方式，沿着｛１１１｝滑移面扩展，而９００℃缺口疲劳裂纹是在交变载荷
研究了定向凝固钴基高温合金ＤＺ４０Ｍ７００℃和９００℃缺口疲劳性能有疲劳断口。结果表明，ＤＺ４０Ｍ合金具有较高的抗高温缺口疲劳破坏能力，７００℃和９００℃缺口疲劳强度分别为２８５ＭＰａ和２０３ＭＰａ，且表现出低的疲劳缺口敏感性，７００℃和９００℃疲劳缺口敏感度仅为０．１４６和．１５３。在交变载茶作用下，７００℃缺口疲劳裂纹是以小平面方式，沿着｛１１１｝滑移面扩展，而９００℃缺口疲劳裂纹是在交变载荷
1998(6):348-351.
Abstract:
研究了Ｔｉ－１１００高温钛合金表面溅射ＮｉＣｒＡｌＹ涂层对钛合金在６００℃－８００℃空气中氧化性能的影响。结果表明：由于在涂层表面形成均匀连续的Ａｌ２Ｏ３保护膜而显著改善了高温钛合金的抗氧化性，涂层本身的微晶组织使其具有良好的抗剥落能力。但在８００℃时，基体中少量Ｔｉ扩散到涂层表面形成ＴｉＯ，同时涂层中的Ｎｉ强烈向基体扩散，在基体和涂层中分别形成扩散带和空洞。
研究了Ｔｉ－１１００高温钛合金表面溅射ＮｉＣｒＡｌＹ涂层对钛合金在６００℃－８００℃空气中氧化性能的影响。结果表明：由于在涂层表面形成均匀连续的Ａｌ２Ｏ３保护膜而显著改善了高温钛合金的抗氧化性，涂层本身的微晶组织使其具有良好的抗剥落能力。但在８００℃时，基体中少量Ｔｉ扩散到涂层表面形成ＴｉＯ，同时涂层中的Ｎｉ强烈向基体扩散，在基体和涂层中分别形成扩散带和空洞。
1998(6):352-355.
Abstract:
The electrochemical and microstructural properties of cast MlNi3. 8C0. 6Mn0.55Ti0.05 have been investigated in detail. The results show that the initial activation and the low-rate discharge capacity are promising, but the high-rate discharge capacity and the discharge voltage plateau are to be improved for this alloy. Segregation, mainly Ti(NiCoMn),was detected using in situ X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). Ti (NiCoMn) segregation makes the alloy easy to pulverize, and consequently decrease the cycle stability of the alloy. The segregation should be avoided to make the full use of Ti.
The electrochemical and microstructural properties of cast MlNi3. 8C0. 6Mn0.55Ti0.05 have been investigated in detail. The results show that the initial activation and the low-rate discharge capacity are promising, but the high-rate discharge capacity and the discharge voltage plateau are to be improved for this alloy. Segregation, mainly Ti(NiCoMn),was detected using in situ X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). Ti (NiCoMn) segregation makes the alloy easy to pulverize, and consequently decrease the cycle stability of the alloy. The segregation should be avoided to make the full use of Ti.
1998(6):360-362.
Abstract:
研究了Ti－Cu－Al阻燃钛合金的阻燃性能和微观组织。结果表明：Ti－Cu－Al合金有良好的阻燃性能，合金的微观组织为a＋Ti2Cu，Ti2Cu分布均匀。随Cu含量或退火温度升高，Ti2Cu颗粒长大，合金性能恶化。合金中是否含有合金元素Al对它的组织结构影响不大。
研究了Ti－Cu－Al阻燃钛合金的阻燃性能和微观组织。结果表明：Ti－Cu－Al合金有良好的阻燃性能，合金的微观组织为a＋Ti2Cu，Ti2Cu分布均匀。随Cu含量或退火温度升高，Ti2Cu颗粒长大，合金性能恶化。合金中是否含有合金元素Al对它的组织结构影响不大。
1998(6):363-366.
Abstract:
Magnetization (M) and susceptibility versus temperature (T) and magnetic field (H) of an internal-Sn processed Nb,Sn wire have been studied and the critical M-H-T surface has been plotted. The normalized magnetization vs. applied field has been filled to Kramer's equation. The effective filament diameter is estimated to be larger than the original filament size. Bridging between the filaments is account for the extra hysteresis. The values of X' and X" do not change much with AC amplitude in a certain background field and frequency, but do change with frequencies for a given AC amplitudes. The interfilament coupling is mainly from bridging, not from proximity effect.
Magnetization (M) and susceptibility versus temperature (T) and magnetic field (H) of an internal-Sn processed Nb,Sn wire have been studied and the critical M-H-T surface has been plotted. The normalized magnetization vs. applied field has been filled to Kramer's equation. The effective filament diameter is estimated to be larger than the original filament size. Bridging between the filaments is account for the extra hysteresis. The values of X' and X" do not change much with AC amplitude in a certain background field and frequency, but do change with frequencies for a given AC amplitudes. The interfilament coupling is mainly from bridging, not from proximity effect.
1998(6):367-369.
Abstract:
研究了以水合联氨作还原剂，从硝酸银和硝酸钯溶液中直接还原出Ａｇ－Ｐｄ合金超细粉末，通过化学势和学分析可知，水合联氨与银，钯反应的标准电极电位差值很大，远远高于银与钯标准电极电位的差值，可以实现银和钯同步还原。在溶液中银和钯离子浓度为７０ｇ／Ｌ．Ａｇ：Ｐｄ＝７：３，水合联氨的加入量为理论量６倍，还原温度为５０℃－６０℃条件下，可获得平均粒径为０．６μｍ的Ａｇ－Ｐｄ合金粉末。
研究了以水合联氨作还原剂，从硝酸银和硝酸钯溶液中直接还原出Ａｇ－Ｐｄ合金超细粉末，通过化学势和学分析可知，水合联氨与银，钯反应的标准电极电位差值很大，远远高于银与钯标准电极电位的差值，可以实现银和钯同步还原。在溶液中银和钯离子浓度为７０ｇ／Ｌ．Ａｇ：Ｐｄ＝７：３，水合联氨的加入量为理论量６倍，还原温度为５０℃－６０℃条件下，可获得平均粒径为０．６μｍ的Ａｇ－Ｐｄ合金粉末。
1998(6):370-372.
Abstract:
研究了用粉末装和技术制备磁体用多芯Ｂｉ－２２２３／Ａｇ超导带材的工艺性能。结果表明，得到的氧化物芯丝均匀的多芯Ｂｉ－２２２３／Ａｇ超导带材，其Ｂｉ－２２２３单相性较好且晶粒具有ｃ轴取向。在７７Ｋ，０Ｔ下，短带的临界电流密度ＪＣ达２．２×１０＾４Ａ／ｃｍ＾２（判据１μＶ／ｃｍ）。用此带制做的小型超导磁体（外径为８５ｍｍ，内径１０ｍｍ，高６０ｍｍ），在４．２Ｋ和７７Ｋ下，磁体通过的临界电流ＩＣ分别为１
研究了用粉末装和技术制备磁体用多芯Ｂｉ－２２２３／Ａｇ超导带材的工艺性能。结果表明，得到的氧化物芯丝均匀的多芯Ｂｉ－２２２３／Ａｇ超导带材，其Ｂｉ－２２２３单相性较好且晶粒具有ｃ轴取向。在７７Ｋ，０Ｔ下，短带的临界电流密度ＪＣ达２．２×１０＾４Ａ／ｃｍ＾２（判据１μＶ／ｃｍ）。用此带制做的小型超导磁体（外径为８５ｍｍ，内径１０ｍｍ，高６０ｍｍ），在４．２Ｋ和７７Ｋ下，磁体通过的临界电流ＩＣ分别为１
1998(6):373-375.
Abstract:
研究了连续区熔定向凝固工艺对铋系织构生长的影响。结果表明，选择合适的粉末名义配比，在最高熔化温度为８８０℃，样品移动速度为８ｍｍ／ｈ的条件下处理样品，能够制得高度取向的Ｂｉ－２２１２晶体。但通过该工艺Ｂｉ－２２２３相织构生长过程的研究，发现这种方法不利于２２２３相织构的生成。
研究了连续区熔定向凝固工艺对铋系织构生长的影响。结果表明，选择合适的粉末名义配比，在最高熔化温度为８８０℃，样品移动速度为８ｍｍ／ｈ的条件下处理样品，能够制得高度取向的Ｂｉ－２２１２晶体。但通过该工艺Ｂｉ－２２２３相织构生长过程的研究，发现这种方法不利于２２２３相织构的生成。
1998(6):376-378.
Abstract:
The effects of particle size on the electrochemical properties of the Ml(NiCoMnTi)5 hydrogen storage alloy have been systematically investigated. The results show that the smaller the particle size, the higher the discharge capacity and the better the high -rate-dischargeability and the cycling stability. If two types of powder with different particle sizes are mixed, the smaller the particle size ratio (the average particle size of small component to that of the large one), the higher the discharge capacity. At a mixing weight ratio (the weight of large component to that of the small one) of 7: 3, the highest discharge capacity is obtained.
The effects of particle size on the electrochemical properties of the Ml(NiCoMnTi)5 hydrogen storage alloy have been systematically investigated. The results show that the smaller the particle size, the higher the discharge capacity and the better the high -rate-dischargeability and the cycling stability. If two types of powder with different particle sizes are mixed, the smaller the particle size ratio (the average particle size of small component to that of the large one), the higher the discharge capacity. At a mixing weight ratio (the weight of large component to that of the small one) of 7: 3, the highest discharge capacity is obtained.
1998(6):379-380.
Abstract:
Some factors effecting the porosity of porous tungsten, such as powder size, press pressure, sintering temperature, and so on, are discussed in detail. It is found that the porosity of the pressed blank is not only connected with the press pressure, but also with the size of tungsten powder. For the same size of powder, the porosity of the pressed blank decreases with the increase of pressing pressure. The porosity of pressed blank of coarse powder is smaller than that of fine powder for the same pressure. If the sintering temperature and time are the same, the porosity of porous tungsten made by fine powder is smaller than that of the coarse one. For the same size powder, the porosity of the pressed blank decreases with increase of sintering temperature. Therefore, the powder size and sintering temperature are major factors for the porosity of porous tungsten. The smaller the size of the powder and the higher the sintering temperature, the less the porosity of porous tungsten.
Some factors effecting the porosity of porous tungsten, such as powder size, press pressure, sintering temperature, and so on, are discussed in detail. It is found that the porosity of the pressed blank is not only connected with the press pressure, but also with the size of tungsten powder. For the same size of powder, the porosity of the pressed blank decreases with the increase of pressing pressure. The porosity of pressed blank of coarse powder is smaller than that of fine powder for the same pressure. If the sintering temperature and time are the same, the porosity of porous tungsten made by fine powder is smaller than that of the coarse one. For the same size powder, the porosity of the pressed blank decreases with increase of sintering temperature. Therefore, the powder size and sintering temperature are major factors for the porosity of porous tungsten. The smaller the size of the powder and the higher the sintering temperature, the less the porosity of porous tungsten.
