非晶态Cu_(56)Zr_(44)合金的结构及其等温退火晶化过程的研究

利用X射线衍射技术、差示扫描量热分析技术和透射电子显微镜研究了非晶态Cu56 Zr4 4合金的结构及其等温退火条件下的晶化过程 .实验结果表明 ,非晶态Cu56 Zr4 4合金在室温下的短程结构类似于硬球无规密堆积分布 .在70 3K过冷液相区内等温退火时发现 ,当退火时间为 3min时 ,晶化产物主要为Cu8Zr3相 ;当退火时间为 6min时 ,Cu8Zr3相完全消失 ,而Cu1 0 Zr7相大量析出 ;当退火时间达到 3 0min以上时 ,其晶化产物转变为Cu1 0 Zr7,CuZr2 ,Cu8Zr3等多种化合物 .由此提出了非晶态Cu56 Zr4 4合金等温退火晶化过程的扩散机理 .

STUDY ON MICROSTRUCTURE AND CRYSTALLIZATION OF AMORPHOUS Cu_( 56) Zr_(44) ALLOY BY MEANS OF ISOTHERMAL ANNEALING

The microstructure and crystallization process of an amorphous Cu 56 Zr 44 alloy at isothermal annealing were studied by using the X-ray diffraction, differential scanning calorimetry and transmission electron micrograph techniques. The experimental results seem to show that the short-range order of amorphous Cu 56 Zr 44 alloy at room temperature is of hard sphere random dense packing. It is found that the crystallization products of amorphous Cu 56 Zr 44 alloy annealed at 703K within its supercooled liquid range is mainly Cu 8Zr 3 phase in an annealing time of 3min, and when the time is 6min, Cu 8Zr 3 phase disappears completely and Cu 10 Zr 7 phase precipitates a lot, while if the time is longer than 30min, several kinds of phases such as Cu 10 Zr 7, CuZr 2 and Cu 8Zr 3 will form. Based on the above the diffusion mechanism of amorphous Cu 56 Zr 44 alloy at isothermal annealing is presented.