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通过光学显微镜、扫描电镜和热重分析等研究了Y对Cu-Si合金微观组织及氧化行为的影响。结果表明,随着合金中Y含量的增加,Cu-3Si-0.5Y和Cu-3Si-1.0Y合金的晶粒尺寸分别较Cu-3Si-0Y合金降低了60%和80%。三种合金在800℃、0.1 MPa纯氧气中氧化24小时后,Cu-3Si-1.0Y合金具有最大的氧化增重,而Cu-3Si-0.5Y合金具有最小的氧化增重。晶粒细化促进了合金内部组元在合金基体和氧化物中的扩散速率,增加了“短路扩散”比率,促进了SiO2和Y2O3的生成。三种成分的合金在实验条件下均未形成连续的SiO2或Y2O3氧化膜,但含Y合金中两种氧化物的快速生成和弥散分布在一定程度上抑制了合金元素和氧的扩散,有助于提高合金的氧化抗力。Cu-3Si-1.0Y合金表现出最大的氧化增重则归因于过高的Y含量使Y2O3在合金氧化总增重中所占的比例明显增加。
The effects of Y on the microstructure and oxidation behavior of Cu-Si alloy were investigated by optical microscopy, scanning electron microscopy and thermogravimetric analysis. The results show that the grain sizes of Cu-3Si-0.5Y and Cu-3Si-1.0Y alloy decrease by 60% and 80% respectively compared with that of Cu-3Si-0Y alloy with the increase of Y content in the alloy. The Cu-3Si-1.0Y alloy has the largest oxidation weight gain when the three alloys are oxidized in 0.1 MPa pure oxygen at 800 ℃ for 24 hours, while the Cu-3Si-0.5Y alloy has the smallest oxidation weight gain. The grain refinement promotes the diffusion rate of the internal components of the alloy in the alloy matrix and the oxide, increases the ratio of “short diffusion” and promotes the formation of SiO2 and Y2O3. The three components of the alloy did not form continuous SiO2 or Y2O3 oxide film under the experimental conditions, but the rapid formation and dispersion of the two oxides in the Y alloy inhibited the diffusion of alloying elements and oxygen to a certain degree, To improve the oxidation resistance of the alloy. Cu-3Si-1.0Y alloy showed the largest oxidation weight gain is attributed to the high Y content of Y2O3 in the total oxidation of the alloy weight gain significantly increased.