【摘要】：在Thermo-Calc熱力學(xué)軟件模擬計(jì)算基礎(chǔ)上,采用光學(xué)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(jī)制的影響。結(jié)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?jǐn)?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(kuò)散及γ/γ′界面能的影響。時效后合金的拉伸強(qiáng)度明顯增加,隨時效時間的延長,拉伸強(qiáng)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(jī)制由位錯熱攀移機(jī)制→位錯切割機(jī)制→Orowan繞越機(jī)制轉(zhuǎn)變?yōu)槲诲e熱攀移機(jī)制→Orowan繞越機(jī)制→位錯切割機(jī)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