加工工艺对Zr-1Nb-0.01Cu合金第二相粒子析出行为的影响

The effects of processing technologies on secondary phase particles precipitation behavior in Zr-1Nb-0.01Cu all

摘要:

本文系统地研究了不同加工工艺对Zr-1Nb-0.01Cu合金第二相粒子析出行为的影响。研究结果表明，随着冷轧和退火次数、中间退火温度和最终退火温度与时间的降低，第二相粒子的平均晶粒尺寸在减小。在温度高于640°C的中间退火过程中形成的β-Zr相在最终的退火过程中很难完全分解。由于Ostwald熟化效应，最终退火时间的延长会导致合金中尺寸较小的第二相粒子通过原子扩散合并成尺寸较大的第二相粒子。与其它加工工艺相比，降低中间退火温度在减小第二相粒子的尺寸方面更为有效。通过低温中间/最终退火（≤520°C）或者缩短退火时间（≤2h）可以获得平均晶粒尺寸小于50nm的第二相粒子。研究结果对调控Zr-Nb系合金第二相粒子的析出行为具有重要意义。

Abstract:

The precipitation behavior of secondary phase particles (SPPs) was investigated systematically in Zr-1Nb-0.01Cu alloy produced by various processing technologies. The results show that with the decrease of cold rolling and annealing steps, intermediate annealing temperatures, final annealing temperatures and time, the average size of SPPs decrease accordingly. The β-Zr phase formed at the intermediate annealing temperature (higher than 640 °C) is hard to dissolve in the matrix after final annealing treatment. During long-time final annealing process, the SPPs with smaller size coalesce into larger particles by diffusion through the matrix gradually because of Ostwald ripening mechanism. It shows that the decrease of intermediate annealing temperature is more effective than the other processing technologies for minimizing the size of SPPs. The average particle size which is smaller than 50nm can be achieved by low intermediate/final annealing temperature (≤520°C) or short annealing time (≤2 hours) treatment. The investigations in the present paper are very meaningful to control the SPPs in Zr-Nb based alloys.