铜基大块非晶合金添加微量元素对腐蚀行为的影响机理研究

通过分子动力学方法模拟了Cu-Al合金液相,然后模拟降温过程得到Cu-Al非晶合金.通过计算机编程建立了Cu-Al-M非晶基体、Cu-Al-M非晶表面及吸附O原子Cu-Al-M非晶表面原子结构模型.利用实空间连分数方法,研究了添加微量合金元素Zr,Nb,Ta,V,Y,Sc对Cu基大块非晶合金的腐蚀行为的影响机理.研究发现合金元素Zr,Nb,Ta,V,Sc不向清洁Cu基非晶表面偏聚,但除Y外向有氧吸附的表面偏聚,说明有氧吸附后Cu基非晶表面偏聚发生逆转.键级积分计算表明Zr,Nb,Ta,V,Y,Sc元素均增大与氧之间的结合力,易形成氧化膜,提高Cu基大块非晶的耐蚀性.稀土Y提高Cu基大块非晶的耐蚀性可能是由于它向合金与氧化膜界面偏聚并提高了合金与氧化膜的结合力.

Study of the influence mechanism of additional elements on the corrosion behavior of bulk Cu-based amorphous alloys

The liquid state Cu-Al alloy system was simulated by using the molecular dynamics method, then Cu-Al amorphous alloy is obtained by cooling process simulation. This article firstly sets up crystalline Cu-Al alloy liquid by using the molecular dynamics. The models of Cu-Al-M bulk amorphous alloys, their clean surfaces and their surfaces with O adsorption are set up by computer programming. The influence mechanism of additional elements Zr, Nb, Ta, V, Y and Sc on the corrosion behavior of bulk Cu-based amorphous alloys are investigated by using real-place recursive method. Results show that the alloying elements do not aggregate on the clean surface of bulk Cu-based amorphous alloys, but tend to aggregate on the surface with O adsorption with the exception of Y, which indicates that the segregation of the bulk Cu-based amorphous alloy surface with O adsorption is reversed. Calculations of the total bond order integral show that additional element can interact with oxygen easily to form oxide film on the surface of Cu-based amorphous alloys, which can improve the corrosion resistance of bulk Cu-based amorphous alloys. The improvement in corrosion resistance of Cu-based metallic glass with Y addition may be due to the aggregation of Y to the interface between alloy and oxide film, which improves the adhesion.