论文部分内容阅读
Kui和我们曾先后报道了采用助熔剂法将Pd_(40)Ni_(40)P_(20)合金包裹能使该合金获得较大的过冷,并在较低的冷却速率下获得了较大尺寸的金属玻璃球。但是,由于用热电偶直接探测合金凝固过程中的相变温度较难(直接插入熔体中会导致非自发形核,放在石英玻璃外部又难以测到热信号),因此,缺乏对合金在热循环处理过程中其相转变温度的变化与凝固组织的对应关系的深入研究,尤其是助熔剂如何捕捉合金表面及熔体内部杂质和加热-冷却的热循环如何钝化杂质的机制尚未见报道。本文设计了一种十分有效的热电偶测温技术,测出了在B_2O_3包裹状态下合金凝固过程中的差热分析曲线,并较详细地研究了Pd_(40)Ni_(40)P_(20)合金的凝固行为,讨论了B_2O_3抑制杂质形核的物理机制。
Kui and we have reported that using flux method to wrap the Pd 40 Ni 40 P 20 alloy can make the alloy get more supercooling and obtain the larger size at the lower cooling rate Metal glass ball. However, the use of thermocouples to directly detect the phase transition temperature during the solidification of the alloy is more difficult (direct insertion into the melt leads to non-spontaneous nucleation, which makes it difficult to measure thermal signals outside the quartz glass) In-depth study of the relationship between the phase transition temperature and the solidified structure in the thermal cycle process, especially how the flux solves the problem of how to passivate the impurities on the surface of the alloy and in the melt and the heat cycle of the heating-cooling has not been reported yet . In this paper, a very effective thermocouple temperature measurement technique was designed, the differential thermal analysis curve of the alloy solidified in the B_2O_3 coating was measured and the effects of Pd_ (40) Ni_ (40) P_ (20) The solidification behavior of the alloys was discussed and the physical mechanism by which B 2 O 3 inhibited the nucleation of impurities was discussed.