【摘要】：在Thermo-Calc熱力學軟件模擬計算基礎上,采用光學顯微鏡、掃描電子顯微鏡、能譜檢測和透射電子顯微鏡研究了Ni-25Cr-20Co合金在長期時效過程中析出相的變化情況及對性能的影響,理論分析了γ′相顆粒粗化對合金拉伸變形過程中第二相與位錯交互作用機制的影響。結果表明:經(jīng)750℃時效后合金中析出MC、M_(23)C_6和γ′相,γ′相的體積分數(shù)約為16%。長期時效后,γ′相顆粒的平均尺寸與時間t符合LSW理論,受溶質(zhì)原子擴散及γ/γ′界面能的影響。時效后合金的拉伸強度明顯增加,隨時效時間的延長,拉伸強度逐漸降低。隨γ′相的粗化,拉伸變形過程中第二相與位錯交互作用的機制由位錯熱攀移機制→位錯切割機制→Orowan繞越機制轉(zhuǎn)變?yōu)槲诲e熱攀移機制→Orowan繞越機制→位錯切割機制。
[Abstract]:On the basis of Thermo-Calc thermodynamics software simulation, the changes of precipitated phases and their effects on the properties of Ni-25Cr-20Co alloys during long-term aging were studied by optical microscope, scanning electron microscope, energy spectrum detection and transmission electron microscope. The effect of 緯 'phase coarsening on the interaction between the second phase and dislocation during tensile deformation of the alloy was analyzed theoretically. The results show that MC,M_ _ (23) C _ (6) and 緯 'phase are precipitated from the alloy after aging at 750 鈩，

本文編號：2279049