Synthesis of copper alloys with extended solid solubility and nano Al2O3 dispersion by mechanical alloying and equal channel angular pressing
Synthesis of copper alloys with extended solid solubility and nano Al2O3 dispersion by mechanical alloying and equal channel angular pressing
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机械合金化和等通道角挤压法合成具有扩展固溶度和纳米Al2O3弥散的铜合金
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发表时间：
2010
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通讯作者：
Indranil Manna
中科院分区：
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作者：
S. Bera;Z. Zúberová;R. Hellmig;Yuri Estrin;Indranil Manna
采用机械合金化/球磨法制备了Cu-4.5wt%Cr和Cu-4.5wt%Cr-3wt%Ag两种含纳米Al 2 O3弥散相（粒径<10 nm）和不含纳米Al 2 O3弥散相（粒径<10 nm）的合金，并在室温下进行了等通道转角挤压（ECAP）。通过X射线衍射以及扫描和透射电子显微镜进行的微观结构表征和相分析提供了在研磨25小时后形成具有纳米（<30 nm）微晶尺寸的富Cu扩展固溶体的证据，具有均匀分散的氧化铝纳米颗粒嵌入其中。纳米晶Al 2 O3通过八个ECAP道次显示出导致具有390 VHN的异常大的硬度和增强的耐磨性的复合材料。不含Al 2 O3的后一种合金的粒料的电导率为约30%IACS（国际退火铜标准），而具有5或10重量% Al 2 O3分散体的粒料表现出约20- 25%IACS的电导率。因此，目前的室温合成和固结路线似乎提供了一个有前途的途径，开发高强度，耐磨/耐腐蚀的铜基电接触纳米陶瓷分散体。
Cu–4.5 wt % Cr and Cu–4.5 wt % Cr–3 wt % Ag alloys, with and without nanocrystalline Al2O3 dispersions (particle size <10 nm), were synthesized by mechanical alloying/milling and consolidated by equal-channel angular pressing (ECAP) at ambient temperature. Microstructural characterization and phase analysis by X-ray diffraction, as well as scanning and transmission electron microscopy, provided evidence for the formation of a Cu-rich extended solid solution with nanometric (<30 nm) crystallite size after 25 h of milling, with uniformly dispersed alumina nanoparticles embedded in it. Consolidation of Cu–4.5 wt % Cr–3 wt % Ag alloy with 10 wt % nanocrystalline Al2O3 by eight ECAP passes was shown to result in a composite with an exceptionally large hardness of 390 VHN and enhanced wear resistance. The electrical conductivity of the pellets of the latter alloy without Al2O3 is about 30% IACS (international annealing copper standard), whereas pellets with 5 or 10 wt % Al2O3 dispersion exhibit a conductivity of about 20–25% IACS. Thus, the present room temperature synthesis and consolidation route appear to offer a promising avenue for developing high-strength, wear/erosion-resistant Cu-based electrical contacts with nano-ceramic dispersion.