W.J. Park
,
S. Ahn
,
R. Schmees
,
and Nack J. Kim(1)(Center for Advaned Aerospace Materials
,
POSTECH. Pohang 790-784
,
Korea )2)(Research Institute of industrial Science & Technology
,
Pohang 790-600
,
Korea )3)(Pratt and Whitney
,
West Palm Beach
,
FL
,
USA Manuscript received 26 August 1996)
金属学报(英文版)
The effects of additions of Ti and W on microstructure and mechanical properties of rapidly solidified Al-Fe-V-Si alloys were investigated. Alloy powders were produced by the centrifugal rotary atomization process. After atomization, powders were screened to various mesh sizes to see the effect of powder size on the mechanical properties.These Powders were consolidated into billets using conventional powder metallurgy process, and then extruded into bar form.Microstructural analysis shows that the W addition results in the heterogeneous microstructure.On the other hand, the Ti addition refines the microstructure.Alloy containing both Ti and W has the highest thermal stability of the dispersoid. These variations in the microstructure are well reflected in the mechanical properties in that the Ti containtng alloys (with or without W) have the higher strength and ductility than the W containing alloy. It also shows that the alloys made of the coarser powders have better combinations of strength and ductility than those made of the finer powders.
关键词:
:rapid solidification
,
null
,
null
李兴无
,
沙爱学
,
储俊鹏
,
张雷
,
路民旭
材料工程
doi:10.3969/j.issn.1001-4381.2007.09.001
通过测试不同淬火温度下的拉伸应力应变曲线、750～790℃淬火拉伸断裂后均匀变形区域的X射线衍射谱研究了淬火温度对Ti-3Al-4.5V-5Mo钛合金形变诱发马氏体的影响.结果表明:该合金在750～790℃淬火后拉伸变形机制为亚稳定β相变形诱发马氏体转变,790℃淬火合金在6.5%的变形量下亚稳定β相基本完全转变为α″马氏体.790℃淬火后拉伸形成应力诱发马氏体,β立方→α″σ;750℃淬火后拉伸形成应变诱发马氏体,β立方→β正方→α″ε.形变诱发α″相在拉伸变形时发生晶格重新取向:[010] α″方向平行于拉伸轴线,[100]α″方向垂直于拉伸轴线.
关键词:
Ti-3Al-4.5V-5Mo
,
形变诱发马氏体
,
α″相
钱善华
,
胡含
,
刘科言
,
李庆忠
材料保护
目前,对液晶材料与蓖麻油混合后的润滑性能研究不多.在四球试验机上开展齿轮油、蓖麻油、含液晶材料4-正戊基-4'-氰基联苯(5CB)添加剂蓖麻油的磨损试验研究,分析了其磨斑直径WSD与负荷的变化规律,初步探讨了液晶添加剂5CB对蓖麻油的作用机理.结果表明:5CB能够改善蓖麻油的润滑性能,最大无卡咬负荷从490 N提高到784 N；当负荷高于784 N时,含3％5CB蓖麻油对应的WSD低于含l％5CB所对应的WSD；当负荷为1 536 N时,含3％5CB蓖麻油出现了烧结现象,而成品齿轮油产生1.28 mm的WSD.5CB添加剂能够改善蓖麻油的润滑性能,但尚不能完全达到或超过矿物油的润滑性能,需在今后的研究中继续改进.
关键词:
润滑性能
,
蓖麻油
,
液晶添加剂
,
4-正戊基-4'-氰基联苯
,
磨斑直径
,
重载工况
侯晓英
,
许云波
,
吴迪
钢铁研究学报
通过实验室热轧试验，研究了不同终轧温度下低硅含磷系热轧TRIP钢的组织特征及性能特点。结果表明：终轧温度由900℃降低到790℃，铁素体体积分数增加，贝氏体体积分数降低，残余奥氏体体积分数变化不太明显；终轧温度900和820℃时，得到贝氏体为基体的室温组织；终轧温度降低到790℃时，低温变形促进了奥氏体到铁素体的相变率，基体组织尺寸为约4．5μm的细小均匀的等轴状铁索体晶粒，而且存在大量位错。与其他工艺相比，终轧温度790℃时具有优良的综合力学性能：抗拉强度825MPa，断后总伸长率21．5％，屈强比0．64。
关键词:
热轧TRIP钢
,
显微组织
,
力学性能
,
低硅含磷
,
终轧温度
杨根仓
,
魏炳波
,
周尧和
材料研究学报
以特制的无机盐玻璃70%Na_2SiO_3+17.7%Na_2B_4O_7+12.3%B_2O_3作为净化剂,去除液态Ni-32.5%Sn 共晶合金中的异质晶核,使过冷度达302K(0.215T_E)。采用高速摄影及快速红外测温技术研究了深过冷熔体的快速凝固行为。发现尽管过冷度超过了以往认为的均质形核临界过冷度0.2T_m,但是Ni-32.5%Sn 共晶合金仍然优先发生界面异质形核,再辉过程中瞬时凝固速度最大可达784mm/s。
关键词:
深过冷
,
rapid solidification
,
crystal nucleation and growth
,
eutectic alloy
,
high speed cinematography
邓晚平
,
王任甫
,
薛钢
,
杨超飞
材料开发与应用
通过恒温拉伸试验测定了10CrNi5MoV钢在室温至930℃温度范围内的断后延伸率和强度,采用热膨胀法测定了试验钢的特征转变温度Ac1、Ac3.结果表明,10CrNi5MoV钢在730 ～770℃温度区间内断后延伸率超过100％,表现出超塑性行为;热膨胀法测定试验钢的特征转变温度Ac1为680℃,Ac3为784℃.钢板具有超塑性行为的温度位于两相区.
关键词:
超塑性
,
断后延伸率
,
两相区
Spectroscopy and Spectral Analysis
In the present paper, oxalic acid was used to reduce V(V) ion to V(IV) ion, then its complex with V(IV) was formed. By this method, four valence states of vanadium ions had different characteristic absorption peaks in the UV-Visible range. Based on these characteristic absorption peaks, qualitative and quantitative spectrophotometric analysis methods for different valence states of vanadium in vanadium battery electrolyte were established. The results showed that the related coefficients of four standard curves of different valence states were greater than 0. 999 0, linearity ranges were 0. 326 similar to 2. 445, 0. 326 similar to 2. 445, 0. 720 similar to 5. 403, and 1. 784 similar to 13. 437 g.L(-1), respectively. The measurement of samples suggested that the spectrophotometric analysis method was suitable for analyzing the concentration of valence states of vanadium with the RSDs (n=6) in the range of 0. 594%similar to 3. 535%.
关键词:
Vanadium battery;Vanadium ion;Valence state;Spectrophotometry;redox flow battery;v(iv)/v(v)
陈德波
,
查五生
,
刘锦云
,
闫燕
,
冉静
,
刘桂明
稀土
doi:10.3969/j.issn.1004-0277.2008.03.018
用环氧树脂粘结剂制备了NdFeB粘结磁体,探讨了粘结剂含量对粘结磁体磁性能和抗压强度的影响规律及机理.当粘结剂含量为1%(质量分数,下同)时,磁粉不能完全被包覆、粘结,磁体密度、磁性能和抗压强度低;当粘结剂含量为5%时,粘结剂体积分数大,稀释了磁体的磁性能,多余的粘结剂也使磁体抗压强度降低.粘结剂含量为2.5%时磁体具有较佳的性能:剩磁Br=0.616T;内禀矫顽力Hcj=784kA/m;最大磁能积(BH)m=58kJ/m3;抗压强度为236MPa.
关键词:
粘结磁体
,
粘结剂含量
,
磁体密度
,
磁性能
,
抗压强度
,
稀土
廖德仲
,
张泰铭
,
王素琴
,
毛立新
,
许怡学
应用化学
doi:10.3724/SP.J.1095.2010.90140
用新戊二醇(NPG)和对苯二甲酰氯(TPA)反应生成"低聚物"中间体,当n(NPG)/n(TPA)由2.4增加至3.0时,中间体的聚合度(m)在3.5～1.45之间,收率75.5%.再将中间体与油酸、菜籽油酸进行酯化得到复合酯,收率88.5%.结果表明,复合酯的粘度随着分子量的增大而增大,粘度指数大于125,凝点低于-27 ℃,氧化稳定性随分子量的增大而提高,生物降解率＞70%,最大无卡咬负荷(P_B)为784 N,磨斑直径0.41 mm,热分解温度＞250 ℃,因此目标产物是性能良好的绿色润滑剂.
关键词:
新戊二醇
,
对苯二甲酰氯
,
油酸
,
菜籽油酸
,
复合酯
,
润滑性能
