【摘要】：為了完善Co基高溫合金動(dòng)力學(xué)數(shù)據(jù)庫(kù),本文利用擴(kuò)散偶法測(cè)定了Co-Mn、Co-Mo二元系及Co-Mn-Mo三元系fcc相中的互擴(kuò)散系數(shù),并利用DICTRA軟件對(duì)該三元系進(jìn)行了完整的動(dòng)力學(xué)優(yōu)化。本研究首先利用擴(kuò)散偶法和EPMA技術(shù),基于Sauer-Freise方法擬合得到了Co-Mn、Co-Mo體系fcc相中的互擴(kuò)散系數(shù)。在此基礎(chǔ)上,結(jié)合文獻(xiàn)中現(xiàn)有的各類擴(kuò)散系數(shù)數(shù)據(jù)(包括實(shí)驗(yàn)和半經(jīng)驗(yàn)數(shù)據(jù)),優(yōu)化得到了Co-Mn、Co-Mo合金fcc相中精準(zhǔn)的原子移動(dòng)性參數(shù)。利用所得參數(shù)計(jì)算得到的各擴(kuò)散系數(shù)與實(shí)驗(yàn)數(shù)據(jù)基本一致,且模擬得到的成分曲線與實(shí)驗(yàn)測(cè)定值吻合較好,因此本文得到的二元系原子移動(dòng)性參數(shù)較為可靠。此外,在總結(jié)前人工作的基礎(chǔ)上,本研究依據(jù)經(jīng)驗(yàn)方法近似給出了Mn-Mo二元系fcc相的原子移動(dòng)性參數(shù)。為了得到較為準(zhǔn)確的Co-Mn-Mo三元系熱力學(xué)數(shù)據(jù)庫(kù),本文首先利用文獻(xiàn)中的相圖數(shù)據(jù)優(yōu)化了Mn-Mo二元系的熱力學(xué)參數(shù),然后通過(guò)合金法測(cè)定了Co-Mn-Mo三元系1175℃時(shí)等溫截面中(fcc+μ)兩相區(qū)的相界,并優(yōu)化了該三元系中l(wèi)iquid、fcc和μ相的熱力學(xué)參數(shù),填補(bǔ)了相關(guān)研究的空白,并為該三元系的動(dòng)力學(xué)優(yōu)化提供了熱力學(xué)參考。在確定Co-Mn、Co-Mo、Mn-Mo二元系動(dòng)力學(xué)參數(shù)的基礎(chǔ)上,本研究利用擴(kuò)散偶法,基于Whittle-Green方法,得到了Co-Mn-Mo三元系fcc相的互擴(kuò)散數(shù)據(jù),并通過(guò)優(yōu)化確定了該三元系fcc相中的原子移動(dòng)性參數(shù)。利用所得參數(shù)計(jì)算得到了該三元系fcc相中的擴(kuò)散系數(shù),在與實(shí)驗(yàn)數(shù)據(jù)對(duì)比后發(fā)現(xiàn)兩者吻合較好,且得到的擴(kuò)散成分曲線與實(shí)驗(yàn)實(shí)際情況基本一致。因此,本研究最終獲得的Co-Mn-Mo三元系原子移動(dòng)性參數(shù)具有較高的準(zhǔn)確性,可為Co基動(dòng)力學(xué)數(shù)據(jù)庫(kù)的建立提供參考。
[Abstract]:In order to improve the dynamic database of Co based superalloys, the interdiffusion coefficients in fcc phase of Co-Mn,Co-Mo binary system and Co-Mn-Mo ternary system have been measured by diffusion couple method. The complete kinetic optimization of the ternary system is carried out by using DICTRA software. In this study, diffusion couple method and EPMA technique were used to fit the interdiffusion coefficient in fcc phase of Co-Mn,Co-Mo system based on Sauer-Freise method. On this basis, the accurate atomic mobility parameters in the fcc phase of Co-Mn,Co-Mo alloy are optimized by combining the existing data of diffusion coefficients (including experimental and semi-empirical data) in the literature. The calculated diffusion coefficients are in good agreement with the experimental data, and the simulated composition curves are in good agreement with the measured values, so the atomic mobility parameters obtained in this paper are more reliable. In addition, based on the previous work, the atomic mobility parameters of fcc phase in Mn-Mo binary system are obtained by empirical method. In order to obtain a more accurate thermodynamics database of Co-Mn-Mo ternary system, the thermodynamic parameters of Mn-Mo binary system are optimized by using the phase diagram data in the literature. Then the phase boundaries of the fcc 渭 region in the isothermal section of Co-Mn-Mo ternary system at 1175 鈩，

本文編號(hào)：2343177