Ti3Al基金属间化合物的研究进展

对Ti3Al基金属间化合物的研究情况及其合金组织、力学性能、影响因素作了概述，并重点介绍了其熔炼技术和铸造特性。最后，展望Ti3Al基金属间化合物在航空航天领域的发展前景。     

Ti-47Al-1.2Ce合金显微组织及富稀土相的形貌

采用水冷铜坩埚真空感应熔炼炉制备了Ti-47Al-1.2Ce合金.通过XRD,SEM,EMPA和TEM等测试方法,研究了Ce对TiAl基合金显微组织的影响以及富稀土相的形貌.实验结果表明,铸态Ti-47Al-1.2Ce合金由等轴晶组成,富稀土相主要以椭球形存在于晶内和以网状存在于晶界;稀土元素的加入,可以减小TiAl相的单胞体积,细化合金晶粒尺寸和层片间距.     

Ti_3Al基金属间化合物的研究进展

对Ti3 Al基金属间化合物的研究情况及其合金组织、力学性能、影响因素作了概述 ,并重点介绍了其熔炼技术和铸造特性。最后 ,展望Ti3 Al基金属间化合物在航空航天领域的发展前景     

模糊神经网络预测钢件热处理后力学性能

综合应用模糊数学和神经网络的知识构造了一个模糊神经网络模型。根据零件的淬火温度、淬火介质、回火温度、回火时间等参数，用该模糊神经网络预测钢件淬火和回火后的力学性能。预测结果表明，该方法速度快，结果较准确，为制定钢件热处理工艺提供了一个新的辅助手段。     

Recent developments in engineering γ—TiAl intermetallics

γ-TiAl based alloys are rapidly being developed for elevated temperature applications,due to their high strength,light mass and good oxidation resistance.However,th disadvantages of TiAl based alloys are low ductility and toughness at room temperature,and poor workability.Grain refinement is one of the most effective ways for improving room temperature tensile properties and hot workability of ordered TiAl based alloys.At present,the majority of research works have focused on alloy modifications through compositional controls,alloying additions,thermo-mechanical processing and production techniques.This article discusses the research status of TiAl based alloys in the aras of microstructure,alloying,processing and applications.     

氢对Zr41.2 Ti13.8 Cu12.5 Ni10 Be22.5 大块非晶合金晶化特性的影响

利用电弧熔炼及铜模快速铸造的方法制备Zr41.2Ti13.8Cu12．5Ni10Be22．5大块非晶合金，通过电解丙三醇和磷酸的电化学法向大块非晶中充入氢。测试了大块非晶态合金中充入氢的含量及体积变化规律，采用XRD，DSC技术研究了氢对大块非晶的晶化特征的影响。结果表明：Zr41．2Ti13．8Cu12．5Ni10Be22．5大块非晶可充入的氢与金属的摩尔比为0．92，体积膨胀3．5％；随着氢含量的增加，玻璃转变温度和晶化温度稍有提高，并使结晶过程不同阶段的放热峰变弱。     

Effects of minor yttrium addition on hot deformability of lamellar Ti-45Al-SNb alloy

The effects of 0.3%（molar fraction, the same below） yttrium addition on hot deformability of lamellar Ti-45Al-5Nb alloy were investigated by simulated isothermal forging tests. The ingots with the nominal compositions of Ti-45Al-5Nb and Ti-45Al-5Nb-0.3Y were prepared by induction skull melting. Simulated isothermal forging tests were conducted on Gleeble 1500D thermo-simulation machine using a 6 mm in diameter and 10 mm in length compressive specimen at the deformation temperatures of 1 100, 1 150, 1 200 ℃ and strain rates of 1.0, 0.1, 0.01 s^-1. The results show that yttrium addition remarkably improves hot deformability of Ti-45Al-5Nb alloy. An appropriate hot deformation processing parameter of Ti-45Al-5Nb-0.3Y alloy is determined as 1 200 ℃, 0.01 s^-1. The flow stresses are decreased by yttrium addition under the same compressive conditions. The activation energies of deformation Q are calculated as 448.6 and 399.5 kJ/mol for Y-free and Y-containing alloys, respectively. The deformed microstructure observation under 1 200 ℃, 0.01 s^-1 condition indicates that Ti-45Al-5Nb-0.3Y alloy shows more dynamic recrystallization. The improvement of hot deformability of Ti-45Al-5Nb-0.3Y alloy induced by yttrium addition should be attributed to that the smaller the original lamellar colonies, the lower the deformation resistance and activation energy of deformation are, and the more the dynamic recrystallization is.     

高温钛合金及TiAl金属间化合物的精密铸造技术及应用前景

本文对高温钛合金及TiAl金属间化合物的发展趋势进行了概述,介绍了钛合金及TiAl金属间化合物水冷铜坩埚真空感应熔炼(ISM)熔模精密铸造技术的研究现状.最后,介绍了高温钛合金及TiAl金属间化合物在航空航天领域与民用领域中的应用和发展前景.     

Ti-22Al-25Nb合金ISM熔炼过程中的成分控制

采用X荧光光谱(XRF)分析水冷铜坩埚真空感应炉熔炼(ISM)加入和不加入稀土Y的Ti-22Al-25Nb合金铸锭成分,分析结果表明,在保证获得成分均匀的合金铸锭的情况下,Al的挥发烧损在28.94%～33.88%之间;加入at为0.5%～1%Y,Y的挥发烧损在w为17.20%～34.26%;采取提高熔化温度降低保温时间的措施可以降低Al的挥发烧损.     

铸造Al-Cu合金凝固参数与枝晶间距的关系

本文介绍了用自行设计的铝合金凝固参数测试装置,研究了铸造铝铜合金凝固参数和铸件的宏观晶粒组织、枝晶结构、化学成分不均匀性的关系。根据实验结果,建立了一次枝晶间距和二次枝晶间距和冷却速度的数学表达式:d_1=135.8V~-0.59,d_2=169.5V~-0.379。