Ni-Ti(-Zr)-P非晶合金的热稳定性及腐蚀行为

Thermal Stability and Corrosion Behavior of Ni-Ti(-Zr)-P Glassy Alloys

采用熔体旋淬法制备了Ni76Ti5P19和Ni73Ti5Zr3P19(at%)非晶合金,对其热稳定性及腐蚀行为进行了研究,并讨论了Zr元素的添加对Ni-Ti-P非晶合金性能的影响。结果表明,Zr元素的添加提高了Ni76Ti5P19非晶合金的玻璃转变温度(Tg)和晶化温度(Tx),但使得过冷液体温度区间(ΔTx)有所降低。电化学实验表明,在NaCl、HCl和H2SO4溶液中,Ni-Ti(-Zr)-P非晶合金发生自钝化,具有良好的耐腐蚀性能,这可能归因于合金表面Ti/Zr和P元素的富集。在同一溶液中,与Ni76Ti5P19非晶合金相比,Ni73Ti5Zr3P19非晶合金具有较高的开路电位和较低的钝化电流密度。在Ni-Ti-P合金中添加元素Zr以替代部分Ni能够在钝化膜中引入ZrO2,从而提高合金表面氧化膜的保护性,改善合金的耐腐蚀能力。

Ni76Ti5P19 and Ni73Ti5Zr3P19 （at%） metallic glasses were prepared by a melt-spinning technique. Their thermal stability and corrosion behaviors were investigated, and the effects of Zr addition on the properties of the Ni-Ti-P glassy alloy were discussed. Results show that Zr addition increases the glass transition temperature （Tg） and crystallization temperature （Tx） of the Ni76Ti5P19 glassy alloy, and decreases its supercooled liquid region （ΔTx）. Electrochemical tests in NaCl, HCl and H2SO4 solutions indicate passivation behavior of the Ni-Ti（-Zr）-P metallic glasses. Their good corrosion resistance can be attributed to the formation of a protective Ti/Zr-and phosphorus-rich layer on the surface of the alloys. Compared with Ni76Ti5P19 glassy alloy, the Ni73Ti5Zr3P19 glassy alloy exhibits higher open-circuit potential and lower passive current density. Partially replacing Ni with Zr in Ni-Ti-P alloy introduces ZrO2 in the passive film, which improves the protection of the surface film and results in a higher corrosion resistance.