摘要
利用气雾法制备了Cu-1.56Cr合金粉末并对其于500℃进行了时效,用高分辨电镜观察了其不同时效阶段的结构,并于时效的前期阶段观察到了两种亚稳结构且均为调制结构。利用电子衍射测定了两种结构的晶格点阵,其中调制结构Ⅰ为在基体的晶格点阵上进行的调制,调制结构Ⅱ为DO3型超结构且与基体之间具有N-W位向关系,是后来体心立方(bcc)单质Cr析出的母相。确定了Cu-1.56Cr合金时效过程的析出惯序为面心立方(fcc)的Cu基固溶体(无序结构)→fcc演化的调制结构Ⅰ→调制结构Ⅱ(典型的DO3结构)→bcc的Cr单质析出相。此两亚稳结构为由fcc过饱和固溶体到bcc析出相的结构变迁提供了过渡。
Cu-1. 56Cr alloy has been prepared by gas-atomization, and the structure of the alloy aging at 500 ℃ at different time were observed. The TEM images show there were two meta-stable structures which were modulated structures at early stage of aging. The lattices were determined by the SAED pat- tern,the modulated structure Ⅰ was modulated based on the lattices of copper. The modulated structure Ⅱ was DO3 structure , the crystallographic relation between the modulated structure and matrix was N-W and probably the modulated structure Ⅱ was matrix of chrome. The precipitation sequence of Cu-1.56Cr alloys was：fcc Cu solution alloy modulated structure I→modulated structure Ⅱ→chrome. Two meta→stable structurs were metastable phase at the transformation from fcc structure to bcc.
出处
《稀有金属与硬质合金》
CAS
CSCD
2006年第4期1-5,共5页
Rare Metals and Cemented Carbides
基金
云南省学术技术带头人后备人才培养项目(2003RC2711)
