崔玉友
,
李东
,
万晓景
金属学报
Ti-Al-V,Ti-Al-Mo和Ti-Al-Nb合金系的实验结果表明,ω相的形成是遵守电子浓度规律的。过渡族元素Ti,V,Mo,Nb的价电子数分别为4(s~2d~2),5(s~2d~3),6(s~1d~5),5(s~1d~4)非过渡族元素Al的价电子数为3(s~2p~1)。此外,合金元素的化学负电性和原子半径对ω相的形成也有影响。综合合金元素的价电子数、化学负电性和原子半径三个因素,钛合金中ω相形成的特征值可定为4.223,其表达式为 4.223=∑Nf_i+0.310Δx/x_(Ti)+0.551Δr/r_(Ti)
关键词:
ω相
,
Ti-alloy
,
electron concentration
,
electronegativity
,
atomic radius
李鑫
,
鲁世强
,
王克鲁
,
傅铭旺
,
李臻熙
,
曹春晓
稀有金属材料与工程
根据Murty失稳判据,利用原始等轴组织的TC11钛合金在780～990℃和0.001～70s-1范围内的等温恒应变速率压缩实验数据,建立了该合金的加工图.依据加工图研究了TC11钛合金的变形机制和变形缺陷与变形热力参数之间的关系.结果表明,在780～990℃和0.001～0.01 s-1范围是超塑性变形区;在780～990℃和高于0.01 s-1范围,易出现β相裂纹和空洞、局部流动以及绝热剪切等流变失稳现象.根据加工图分析,结合微观组织观察结果,并考虑变形抗力的大小,确定出了较佳的变形热力参数范围为850～940℃和0.001～0.01 s-1,最佳的变形热力参数在900℃和0.001 s-1附近.
关键词:
钛合金
,
Ti-6.5Al-3.5Mo-1.5Zr-0.3Si
,
工艺优化
,
Murty失稳判据
,
变形机制
杨合
,
孙志超
,
樊晓光
,
高鹏飞
,
武川
航空材料学报
doi:10.11868/j.issn.1005-5053.2014.4.007
高性能钛合金大型复杂构件精确塑性成形是航空航天高端装备实现大运力、低能耗、长寿命的必然选择,然而,面临如何提高成形制造能力和如何实现成形成性一体化控制的挑战.等温局部加载近β锻造为该类构件的成形提供了一种先进的工艺途径.由于成形过程的特殊性、构件结构的复杂性以及钛合金组织对成形方式与条件的敏感性,使得如何实现微观组织控制并获得性能优异的三态组织成为该成形技术研究发展与应用迫切需要解决的关键问题和基础性难题.从钛合金等温局部加载多道次成形组织演化机制、不同加载区和过渡区组织均匀性控制和三态组织形成及等温局部加载参数优化进行分析并给出了最新的研究进展.
关键词:
钛合金
,
大型复杂构件
,
等温局部加载
,
近β锻造
,
组织控制
Yongbo XU
,
M.A.Meyers
材料科学技术（英文）
Microstructures of the localized shear bands generated during explosion with a thick-walled cylinder specimen in Ti-6Al-4V alloy, were characterized by TEM and SEM. The results show that the twinning is a major mode of deformation, and the distortion-free grains in the bands with the size of 10 µm in diameter were proposed to be the re-crystallization during dynamic explosion. The further observations show that the α→α2 phase transformation may occur in the bands, and this kind of transformation could be confirmed by its dark field image and electron diffraction analysis. Analysis shows that there is specified orientation between the α→α2 Phases.
关键词:
Shear localization
,
null
,
null
,
null
Daoxin LIU
,
Xiaodong ZHU
,
Bin TANG
,
Jiawen HE
材料科学技术（英文）
Ion beam enhanced deposition (IBED) was employed to increase the fretting fatigue resistance of Ti6Al4V. CrN and TiN hard coatings were applied on the base material and shot peening was combined with the hard coatings to study the duplex effect on fretting fatigue resistance. The IBED coatings exhibited a good bonding strength. They did not spall off even after shot peening. However, an optimum composition of CrN showed better fretting fatigue resistance than that of TiN with the same processing parameters.
关键词:
Fretting fatigue
,
null
,
null
,
null
