【作者】 李旭；

【导师】 周清；

【作者基本信息】 南京航空航天大学 ， 航空宇航制造工程， 2012， 硕士

【摘要】 TA9钛合金作为一种在纯钛中加入少量的贵金属Pd形成的对酸性介质具有极好的耐腐蚀性的合金，无毒副元素Al和V的存在，将成为替代纯钛和Ti-6Al-4V应用于植入生物医用的优质材料。热变形过程的微观组织变化复杂，采用数值模拟方法，研究热变形过程微观组织的演变，为预测和控制组织变化，优化加工工艺参数，缩短工艺周期提供理论依据。通过建立目前广泛应用于微观尺度的数值模拟方法：蒙特卡罗波茨模型、几何拓扑模型、相场理论模型、元胞自动机模型、结合微观组织演变的有限元模型等数值模型，定性的模拟了微观组织演化的单相与两相晶粒粗化、动态再结晶等研究热点，对比了不同模拟方法的优缺点，根据本课题的研究需要，最终选定元胞自动机模型。采用元胞自动机数值模拟方法，借助Matlab编程语言，建立了二维与三维系统中晶粒生长、二相粒子钉扎、热变形过程动态再结晶的多种模型，研究了各向异性条件下纯钛晶粒生长，TA9钛合金晶粒生长、TA9钛合金热变形过程动态再结晶行为，同时对TA9钛合金进行不同温度条件的热处理试验和不同变形条件的热拉伸试验，最终将模拟结果与试验结果进行充分对比。研究结果表明：本文建立的结合金属材料学的元胞自动机模型准确反映了TA9钛合金热塑性变形的各项规律，为热塑性成形过程微观组织的控制和预测奠定了基础。更多还原

【Abstract】 TA9titanium alloys have excellent corrosion resistance by adding a small amount of Pd. Inparticular, there were no harmful elements Al and V. TA9titanium alloys will become kinds ofhigh-quality materials which are uesd in biomedical instead of pure titanium and Ti-6Al-4V.The microstructure evolution during thermal deformation is very complicated. Using numericalmethods to investigate the microstructure evolution is important in predicting, controling themicrostructure and optimizing the process parameters. In this paper, by establishing several numericalsimulation methods: monte carlo potts model, topological model, phase-field model,cellular automatamodel and finite element model, single-phase and two phases grain coarsening, dynamicrecrystallization were simulated. Finally, by comparing the advantages and disadvantages of differentsimulation methods, cellular automata method was selected in the work.By using cellular automata method and Matlab programming language, grain growth model,second phase particles pinning model, dynamic recrystallization model were established. Anisotropicgrain growth of pure titanium and TA9titanium alloys, dynamic recrystallization of TA9titaniumalloys were investigated. Meanwhile, heat treatment experiments and hot tensile test under differentdeformation conditions were studied; finally simulation and experimental results were compared. Theresults show that the cellular automata model accurately reflected the thermoplastic deformation lawof TA9titanium alloys, which are beneficial for predicting and controlling the microstructure.更多还原