Al、Si元素含量对高温低膨胀合金组织及性能的影响

The effect of Al and Si element content on the structure andproperties of high temperature low expansion alloy

研究了Al、Si元素微调对Incoloy909合金组织及性能的影响。结果表明:Si元素含量的提高,有利于合金中Laves相及ε相的析出,使得合金中晶粒分布更加细小均匀,提高了合金高温持久寿命。Al元素含量的提升,使得合金在双时效热处理后,析出更多γ′强化相,提升了合金的强硬度。Al、Si元素的微调对合金平均线膨胀系数影响不大,固溶+双时效热处理后合金内部位错密度降低,γ′强化相弥散析出,组织更加稳定,平均线膨胀系数有所降低。

The effect of Al and Si elements on the microstructure and properties of Incoloy 909 alloy was studied.The results show that the increase in Si element content is conducive to the precipitation of Laves and ε phases in the alloy,making the grain distribution in the alloy finer and more uniform,and improving the high-temperature rupture life of the alloy.The increase in Al element content leads to the precipitation of more strengthening phases in the alloy after double aging heat treatment,which enhances the strength and hardness of the alloy.The Al and Si elements fitting has little effect on the average linear expansion coefficient of the alloy.After heat treatment,dislocation density of the alloy decreases,and the strengthening phase disperses and precipitates.The structure is more stable,and the average linear expansion coefficient is reduced.