Cu时效硬化钢中Cu的析出

研究了Cu在工业试制的高强度船体钢中的时效析出行为及其时效硬化规律。结果表明：500～550℃时效,硬度随时间增加很快达到峰值,然后再降低;时效温度对Cu的硬化效果起决定性作用。1．5～2h时效硬化峰值温度约为500℃。在硬化峰值温度下,大量Cu析出相在位错线和板条界上析出,尺寸小于5nm,产生强烈沉淀强化作用。过时效状态下,Cu析出相发生明显长大,析出相形态由球状颗粒转变为杆状或短棒状,沉淀强化作用也随之减弱。     

Cu/Mo/Cu平面层状复合材料的研究进展

总结了Cu/Mo/Cu平面层状复合材料的特点和应用,通过平面层状结构设计,可以实现其在平面(x,y)方向更低的热膨胀系数和更高的热导率,其中热导率最高可达370W·m-1·K-1;介绍了其研究现状和制备方法,并通过对制备工艺的对比分析,指出热压复合和轧制复合是Cu/Mo/Cu层状复合材料生产工艺的发展趋势及方向.     

Cu-W、Cu-Mo薄膜的微观结构及显微硬度分析

采用磁控共溅射方法分别制备了含有W和Mo两种不同成分的铜系薄膜,用EDX、XRD、SEM和纳米压痕仪对薄膜成份、结构、形貌和显微硬度进行了分析。结果表明,制备出的Cu—W和Cu-Mo薄膜均呈晶态结构,Cu-W和Cu—Mo形成了均匀的固溶体;经650℃热处理1h后,Cu—W和Cu—Mo薄膜中晶粒长大,有富w和富Mo相从基体Cu相中弥散析出;Cu-W薄膜的显微硬度随W成分的增加先增加后降低;Cu—Mo薄膜的显微硬度随Mo成分的增加而持续升高,薄膜退火态的显微硬度低于沉积态。分析认为,以上结果的产生均因添加W、Mo所引起的晶粒细化效应和薄膜的热稳定性较差所致。     

Interfacial reactions in molten Sn/Cu and molten In/Cu couples

The interfacial reactions of molten Sn and molten In with solid Cu substrate were determined by studying their reaction couples. The annealing temperature was 300 °C. The phases formed at the interface were examined by optical microscopy, scanning electron microscopy, and electron probe microscopy analysis (EPMA). The thickness of the reaction layers was measured using an image analyzer. For Cu/Sn couples, two phases, ε and η, were found. Only the Cu₁₁In₉ phase was observed at the interface of the Cu/In couples. In comparison with the results of couples of solid Sn and solid In with solid Cu substrate, their phase formation sequences were similar; however, the interfacial morphology and the reaction rates were different. For the liquid/solid couples, the reaction rate was much faster and the interface was nonplanar. A mathematic model was also proposed to describe the dissolution of the Cu substrate and the growth of the intermetallic compounds. Fast dissolution of the substrate was observed in the beginning of the reaction and was followed by a relatively slow growth of the intermetallic compounds at the interface.     

The morphology and thermal stability of the Cu−Cu2S eutectic system

A study has been made of the morphology of unidirectionally solidified and as-cast Cu?Cu₂S eutectic alloys. The growth morphology of the eutectic is rod-like, consisting of rods of Cu₂S which are circular in cross-section in a copper matrix. Following solidification, the Cu₂S rods neck down, pinch off, and spheroidize in a sequence which has previously been termed “ovulation”. The spheroids subsequently coarsen rapidly by a process which is controlled by the volume diffusion of sulfur in copper.     

Thermodynamic properties of the Cu−Sn and Cu−Au systems by mass spectrometry

The activities and partial molar heats of mixing have been determined in the liquid Cu?Sn system at 1320°C and the liquid Cu?Au system at 1460°C. The experimental technique consisted of the analysis of Knudsen cell effusates with a T.O.F. mass spectrometer. The ion current ratio for the alloy components was measured for each system over a range of temperature and composition and the thermodynamic values calculated by a modified Gibbs-Duhem equation. Both systems exhibited negative deviations from ideal behavior. The results can be partially represented by the equations $$\begin{gathered} \log \gamma _{Cu} = - 0.0175x^2 _{Sn} - 0.302 (0 \leqslant x_{Cu} \leqslant 0.20) \hfill \\ log \gamma _{Sn} = - 0.342x^2 _{Cu} + 1.084(0 \leqslant x_{Sn} \leqslant 0.20) \hfill \\ \end{gathered} $$ for the Cu?Sn system at 1320°C and by $$\begin{gathered} \log \gamma _{Cu} = - 0.703x^2 _{Au} - 0.083(0 \leqslant x_{Cu} \leqslant 0.52) \hfill \\ \log \gamma _{Au} = - 1.057x^2 _{Cu} + 0.098(0 \leqslant x_{Au} \leqslant 0.47) \hfill \\ \end{gathered} $$ for the Cu?Au system at 1460°C.     

Role of Cu During Sintering of Fe0.96Cu0.04 Nanoparticles

Metallurgical and Materials Transactions A - Nanoparticle agglomerates of passivated Fe (n-Fe) and Fe0.96Cu0.04 (n-Fe0.96Cu0.04), synthesized through the levitational gas condensation (LGC)...