CAJ | 학술논문

Ni-Co高温合金广泛用于生产燃气涡轮机叶片和热交换器等工作于高温和腐蚀环境的零部件,采用改良静滴法测定了1773～1873K温度范围内熔融Ni,Ni-(5～10)%Co合金在Al2O3基板上Ar+3%H2气氛下的表面张力.熔融Ni,Ni-(5～10)%Co合金的表面张力随着温度的升高而降低.在此基础上采用Butler模型推导了表面张力随温度与浓度的变化,计算了合金体系中元素的偏聚.结果表明,Co在合金表面的浓度低于在体相的浓度.
Ni-Co고온합금엄범용우생산연기와륜궤협편화열교환기등공작우고온화부식배경적령부건,채용개량정적법측정료1773～1873K온도범위내용융Ni,Ni-(5～10)%Co합금재Al2O3기판상Ar+3%H2기분하적표면장력.용융Ni,Ni-(5～10)%Co합금적표면장력수착온도적승고이강저.재차기출상채용Butler모형추도료표면장력수온도여농도적변화,계산료합금체계중원소적편취.결과표명,Co재합금표면적농도저우재체상적농도.
Ni-Co super-alloy is widely used in high temperature and corrosive environments such as gas turbine engines and heat exchangers. The surface tensions of molten Ni and Ni-Co (5 and 10 mass fraction) alloys were measured at the temperature range of 1773～1873 K using an improved sessile drop method with an alumina substrate in an Ar+3%H2 atmosphere. The surface tensions of molten Ni and Ni-Co (5 and 10 mass fiaction) alloys decrease with increasing of temperature. On the basis of experimental data, the surface tension was also theoretically deduced both as functions of concentration and temperature using a model of Butler' equation. The alloy element segregation in this system was calculated. Cobalt concentration on surface of alloys is lower than that in bulk.