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TEMPERATURE DEPENDENCE UPON VISCOSITY OF Ni-P ALLOY ON AMORPHOUS FORMATION

WANG Jingtang PANG Dexing DING Bingzhe BIAN Maoshu LI Shuling Institute of Metal Research , Academia Sinica , Shenyang , China[Originally published in ACTA METALL SIN (CHINESE EDN) 24 (5) 1988 pp B372—B375 , received 25 December 1986 , in revised form 3 September 1987]

金属学报(英文版)

The viscous flow of amorphous alloys near T_gis closely related to the viscosity of liquid alloys. On the basis of the measured surface tension and density for Ni-P binary alloys,the correla- tion between the viscosity of the melt and viscous flow process of the amorphous alloy is inves- tigated.The relationship between viscosity and temperature for Ni-P alloys going from liquid to amorphous solid may be described by the following formula:

关键词: Ni-P amorphous alloy , null , null

Mechanical alloying and characterization of Ni50Al25Ti25

Journal of Alloys and Compounds

An amorphous-like phase, the mixture of amorphous phase and microcrystalline beta-Ni(Al,Ti) compound, has been synthesized by mechanically alloying the Ni50Al25Ti25 elemental powder mixtures in a high energy ball mill. It has been found that titanium plays a dominant role in this process. There exist two types of transformations of amorphous-like Ni50Al25Ti25 upon heating: first, the amorphous-like alloy transforms into a disordered Ni2AlTi compound (b.c.c. structure) at 345-445 degrees C, and then into an ordered Ni2AlTi compound at 554-626 degrees C. Tt is suggested that at the low-temperature transition, the Ni atoms locate in the corners of the b.c.c. lattice, but the cubic centers are occupied randomly by Al and Ti atoms. When the temperature rises to 554 degrees C, a long-range ordering transition occurs, resulting in the formation of ordered Ni2AlTi. The ordering energy of Ni2AlTi has been measured as 4.35 kJ mol(-1).

关键词: mechanical alloying;phase transition;Ni-Al-Ti alloys;intermetallic compounds

1986年国际重要腐蚀会议简表

中国腐蚀与防护学报

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Superplasticity in a directionally solidiried multiphase Ni-25Al-25Cr alloy

Zeitschrift Fur Metallkunde

A Ni-25Al-25Cr (at.%) alloy was directionally solidified under Ar atmosphere in an A1(2)O(3)-SiO2 ceramic mold by the standard Bridgman method. The microstructure of the as-fabricated alloy was studied using optical microscopy, X-ray diffraction and scanning electron microscopy. The alloy was composed of beta-NiAl dendritic arms, alpha-Cr interdendritic regions, fine alpha-Cr particles in the dendritic arms, and beta-NiAl + alpha-Cr eutectic in the interdendritic regions. The mechanical properties were studied by tensile tests in the temperature range 1123 - 1373 K. The results showed that the alloy exhibits superplastic behavior at appropriate testing conditions. The balance between work hardening (by dislocation glide) and work softening (by dynamic recovery and recrystallization) is responsible for the large tensile elongation of the alloy.

关键词: NiAl;superplastic behavior;casting;microstructure;internal-stress superplasticity;polycrystalline materials;large;grains;transformation;deformation;microstructure;intermetallics;mechanism;creep;iron

Microstructure and properties of vacuum induction melted CuCr25 alloys

Journal of Alloys and Compounds

The CuCr25 alloys prepared by vacuum induction melting (VIM) were investigated. The experimental results show that W and Ni had significant influence on the microstructure of CuCr25 alloys. For CuCr25Ni0.5 and CuCr25W1 alloys, the Cr phase was dramatically refined and presented nodular morphology. W could increase the breakdown strength of CuCr25. The electric conductivity of CuCr25Ni0.5 decreased, but still reached the level of conventional CuCr alloys. The other properties of CuCr25Ni0.5 and CuCr25W1 alloys did not degrade. (C) 2003 Elsevier B.V. All rights reserved.

关键词: CuCr25 alloys;vacuum induction melting;arc erosion rate;breakdown;strength;contact materials;electrode material;interrupters;strength;voltage

Ti-25Cu-25Zr钎料与纯钛的钎焊工艺

杨永福 , 巨建辉 , 叶建林 , 艾建玲 , 雷忠荣 , 付维军

稀有金属材料与工程

采用爆炸复合工艺,制成Ti-Cu-Zr 3层复合钎料坯,经轧制得到0.2 mm厚度的钎料箔.研究了Ti-25Cu-25Zr钎料钎焊纯钛的工艺及性能.利用瞬间液相扩散焊原理,分析钎料与钛基体之间的接触反应焊接机制,实验得到钎焊钎缝强度与保温时间的关系.结果表明,钎焊保温时间小于1.0 s时,由于钎料组元和钛基体之间的扩散还不充分,接头的断裂载荷在600 N以下,断裂发生在钎缝上;钎焊保温时间大于1.0 s时,钎料组元和钛基体之间发生了明显的扩散,接头强度显著提高,断裂载荷达到700 N,断裂发生在钛基体的热影响区;保温时间在1.0～4.0 s范围内时,接头强度趋于一致.

关键词: 钎料 , 钎焊 , 钛 , Ti-25Cu-25Zr

航空发动机用 BT25和 BT25 y热强钛合金评述

魏寿庸 , 王青江 , 何瑜 , 陈占乾 , 刘羽寅

钛工业进展

BT25和BT25 y是含有高熔点金属W的Ti-Al-Zr-Sn-Mo-W-Si系马氏体钛合金，由于其优异的热强性能在航空发动机中得到应用。概述了BT25和BT25 y钛合金的加工工艺、热处理工艺对性能的影响及其室温和高温的力学性能等。介绍了宝钛集团有限公司等单位合作研究热强钛合金---BT25、 BT25 y及BT25 y改进型的状况，通过添加与钛熔点和密度相近的多元中间合金，保证了这三种合金成分的均匀性，力学性能达到国外同类合金的水平。

关键词: 热强钛合金 , BT25 , BT25 y , 制备工艺 , 性能

MICROSTRUCTURE AND PROPERTIES OF CuCr25 ALLOYS WITH DIFFERENT Ni CONTENT

C.Y.Zhang , Y.P.Wang , Z.M.Yang , B.J.Ding , Y.L.Li

金属学报(英文版)

CuCr25 alloys containing different Ni content were prepared by vacuum induction melting(VIM)l.The microstructure and proerties were tested.The results show that with the increase of Ni content in CuCr25 alloys,the Cr phase changed from developed dendrite into nodular grains and was drastically refined;the electrical con-ductivity significantly decrease,but still reach the level of convenlional CuCr50 when the Ni content is below 0.5The Ni content had little influence on their breakdown strength.The first breakdown sites transferred to the boundoary of Cu and Cr phase for CuCr25Ni compared to the Cr phase for CuCr25 without Ni.

关键词: CuCr25 , null , null

CuCr25合金的机械变形及性能

周志明 , 蒋鹏 , 王亚平

稀有金属材料与工程

采用真空熔炼制备的CuCr25合金,在低应变速率下冷轧变形,研究了组织及性能变化.结果表明:CuCr25合金的电导率随着轧制变形程度的增大,开始略有上升,然后不断下降,经过一定量的大变形后,电导率又有上升;CuCr25合金的硬度不断上升,CuCr25合金硬度的上升主要是由于Cu基硬度的上升;经过大量的冷轧变形后,Cr相成纤维状和条带状,并有空洞生成;CuCr25合金在室温下具有超塑性.

关键词: CuCr25合金 , 高强高导 , 冷轧 , 超塑性