纤维增强TiAl基复合材料的研究

介绍了纤维增强TiAl基复合材料在制备、界面和力学性能等方面的研究和进展。指出纤维增强TiAl基复合材料是发挥TiAl基合金潜力的一个重要方面。同时，也讨论了纤维增加TiAl基复合材料所面临的一些问题。     

颗粒增强TiAl基复合材料的研究进展

综述了国内外颗粒增强TiAl基复合材料的研究现状;对TiAl基复合材料基体和增强颗粒的选择,TiB2、Al2O3等颗粒增强TiAl基复合材料的制备工艺和力学性能进行了重点讨论,并阐述了各种制备方法的优缺点及发展方向     

高推重比航空发动机用新型高温钛合金研究进展

综述了我国航空发动机用高温钛合金材料体系的发展状况．针对未来高推重比航空发动机对新型轻质耐高温结构材料的需求,重点介绍了TiAl合金和SiC纤维增强钛基复合材料2种关键的新型高温钛合金国外研究进展和应用情况。目前我国航空发动机主要应用的是α＋β型钛合金,工作温度均在500℃以下,在更高温度使用的近α型钛合金（如600℃高温钛合金）尚处于研发阶段。国外对TiAl合金的研究已近20年,在航空发动机领域已公开报导了10多种TiAl零部件,并且完成了地面装机试验,试验结果非常理想。SiCf／Ti复合材料在航牵发动机上的典型应用是叶环类和轴类零件,美、英等国均研制出了多个零部件,并进行了发动机考核试验。TiAl和SiCf／Ti复合材料将是新一代高推重比航空发动机用的2种关键结构材料。     

铝基复合材料的制备工艺

介绍了连续纤维、晶须（或短纤维）及颗粒作为增强体的铝基复合材料的性能和应用，总结了国内外铝基复合材料的制备工艺。     

颗粒增强铸造铝基复合材料的研究状况

介绍了颗粒增强名基复合材料的制造工艺，影响铝基复合材料制造工艺的主要因素以及颗粒增强铝基复合材料的应用前景。同时还介绍了我们制备颗粒墙强铝基复合材料的试验情况。将碳化硅颗粒增强粉料经氟盐预处理再加入过热铝熔体，经搅拌可以制造出碳化硅颗粒均匀分布的名基复合材料。     

中国钛发展的四十年

系统介绍了钛基复合材料的最新研究和发展，涉及非连续颗粒增强和连续纤维增强两大类钛基复合材料近１０多年来的研究成果和发展趋势；重点评述了钛基材和增强剂的选择，增强剂与基体界面反应的研究，扩散障碍涂层技术和钛基复合材料制造工艺的研究和发展，讨论了钛基复合材料的应用前景。     

Cf／Al复合材料与TiAl电子束诱导自蔓延焊接机理及动力学研究

采用自蔓延连接的方法实现了碳纤维增强铝基复合材料（Cf/Al）与TiAl合金的连接,系统研究了二者在自蔓延连接中界面形成机制。     

微纳米颗粒增强TiAl基复合材料组织与室温力学性能

原位自生颗粒增强金属基复合材料是提高金属材料强韧性的有效途径,采用放电等离子烧结技术(SPS),以氧化石墨烯、碳化硅、氮化硼为增强体,原位自生制备TiAl基复合材料,研究第二相对TiAl基复合材料显微组织演变及室温性能的影响。结果表明,增强体的改变直接影响了TiAl基复合材料第二相形貌和分布。添加石墨烯在TiAl合金α₂和γ片层界面处弥散析出微纳米尺度第二相Ti₂AlC;添加碳化硅在基体中分别生成微米级晶界相Ti₅Si₃,微纳米片层间相Ti₂AlC;添加氮化硼未能在TiAl合金α₂和γ片层界面处析出微纳米第二相,而是纳米级TiB₂和Ti₂AlN相析出在晶界处与基体形成连续核壳结构;复合添加石墨烯和氮化硼既能在片层间原位析出Ti₂AlC相,又能在晶界处形成核壳结构。TiAl基复合材料的室温压缩性能和摩擦磨损性能均得到有效提高,复合添加石墨烯和氮化硼可获得优异的室温力学性能。TiAl基复合材料的...     

大块金属玻璃基复合材料制备技术研究进展

介绍了国内外几种制备大块金属玻璃基复合材料的方法和形成的组织，阐明了组织中增强相对力学性能的影响，展望了大块金属玻璃基复合材料的发展趋势。     

原位颗粒增强镁基复合材料的制备

综述了原位颗粒增强镁基复合材料的研究进展，重点介绍了原住反应法制备颗粒增强镁基复合材料的基本原理和过程，并分析了其组织和性能；同时还简述了传统铸造法制备原位颗粒增强镁基复合材料的特点。最后，对原位颗粒增强镁基复合材料的发展趋势作了展望。     

TiNb／Ti—48Al—2Cr—2Nb复合材料的力学性能和断裂特征

采用粉末冶金、热压成型工艺制备了TiNb/Ti-48Al-2Cr-2Nb(TACN)基复合材料。研究了复合材料的弯曲性能和断裂特征。实验结果表明：复合材料的性能较基体有较大的提高,用混合法则来进行预测复合材料的力学性能和实验中所得结果十分接近;这种工艺制备的复合材料界面由全片层组织构成,纤维和基体的结合状态良好,纤维损伤比例较小。     

TiNb纤维强韧化TiAl基复合材料高温拉伸性能的研究

采用粉末冶金法和 1 2 50℃、2 0 MPa× 2 .5h热压工艺制备 Ti Nb纤维强韧化 Ti- 48Al- 2 Cr- 2 Nb( TACN)基复合材料。测试了复合材料的高温拉伸性能。结果表明 ,复合材料的高温性能优于基体。使用这种工艺制备的复合材料界面由全片层组织构成 ,纤维和基体的结合状态良好 ,纤维损伤比例较小 ,说明此工艺是制备 TACN复合材料的有效方法。     

Er掺杂强韧化Al_2O_3/TiAl复合材料

以Ti、Al、TiO2为起始原料,以Er2O3为掺杂剂,原位热压合成了Er掺杂Al2O3/TiAl复合材料。通过XRD、SEM分析及力学性能测试,研究了不同Er2O3引入量对合成Al2O3/TiAl复合材料微观结构和力学性能的影响。结果表明:复合材料主要由TiAl、Ti3 Al、Al2 O3相和少量Al10 Er6 O24相组成,含Er相主要分布在基体相晶界处;掺杂0.01 mol Er2 O3制得的复合材料,经1250℃保温2 h真空热压烧结后表观断裂韧性达到最大值(10.41 MPa.m1/2),经1300℃保温2 h真空热压烧结后弯曲强度达到最大值(456.06 MPa);当Er2O3掺杂量增加到0.02 mol时,复合材料的弯曲强度和表观断裂韧性均呈减小趋势。微观结构分析表明,掺杂0.01 mol Er2O3的复合材料断口毛糙,颗粒尺寸变小,增强相分布较均匀,表明适量的Er2O3掺杂可细化复合材料晶粒尺寸,提高增强颗粒分布均匀度,起到增强增韧的效果。     

Fabrication and mechanical properties of Ti2AlC/TiAl composites with co-continuous network structure

Ti₂AlC/TiAl composites with different volume fractions were prepared by hot pressing technology, and their reinforced structural characteristics and mechanical properties were evaluated. The results showed that when the reinforced phase volume fraction of Ti₂AlC was 20%, three-dimensional interpenetrating network structures were formed in the composites. Above 20%, Ti₂AlC phase in the composites accumulated and grew to form thick skeletal networks. The microplastic deformation behavior of Ti₂AlC phase, such as kink band and delamination, improved the fracture toughness of the composites. Comparative analysis indicated that the uniform and small interconnecting network structures could further reinforce the composites. The bending strengths of composites prepared with 20 vol.% Ti₂AlC reached (900.9±45.0) MPa, which was 25.5% higher than that of TiAl matrix. In general, the co-continuous Ti₂AlC/TiAl composite with excellent mechanical properties can be prepared by powder metallurgy method.     

Interfacial reaction studies of B4C-coated and C-coated SiC fiber reinforced Ti–43Al–9V composites

The interfacial reactions of B₄C-coated and C-coated SiC fiber reinforced Ti–43Al–9V composites were investigated by scanning electron microscope and transmission electron microscope. The detailed microstructures as well as the chemical composition throughout the reaction zone were identified. For SiC_f/B₄C/TiAl composite, the reaction zone from B₄C coating to TiAl matrix is composed of 4 layers, namely, a carbon-rich layer, a mixed layer of TiB₂ + amorphous carbon, a TiC layer and a mixed layer of TiB + Ti₂AlC. For SiC_f/C/TiAl composite, the reaction zone from C coating to TiAl matrix is composed of 3 layers, namely, a fine-grained TiC layer, a coarse-grained TiC layer and a thick Ti₂AlC layer. For both kinds of composites, the reaction mechanisms of the interfacial reactions were analyzed, and the corresponding reaction kinetics were calculated. The activation energies of interfacial reaction in SiC_f/B₄C/TiAl composite and SiC_f/B₄C/TiAl composite are 308.1 kJ/mol and 230.7 kJ/mol, respectively.     

碳化硅纤维增强体钛铝基体的原位合成与控制及其动力学解析

利用磁控溅射,采用钛靶和铝靶按照一定功率比在SiC纤维表面沉积钛与铝,制备SiC纤维的Ti-Al基复合先驱丝,按密排堆垛置于包套之中并经热等静压制备碳化硅纤维增强钛铝基试样。通过扫描电镜观察组织形貌,研究热等静压及真空热处理对组织结构、界面反应层的影响,应用XRD与能谱分析,研究磁控溅射功率对原子比的影响以及钛铝原位反应过程中相比例的变化规律,采用差示扫描量热法(DSC,differential scanning calorimetry)对钛铝反应进行动力学分析。结果表明,钛靶与铝靶的溅射功率直接影响钛铝的原子比,TC4和Al靶功率分别为13和4.5 kW/m2,其铝含量为27at%;TC4和Al靶功率分别为13和8.3 kW/m2,其铝含量为49at%。此外,动力学研究表明,Al3Ti是钛铝反应的优先生成相,随着Al的扩散,逐渐形成TiAl、Al2Ti和Ti3Al,但经过Al的充分扩散,其最终形成的稳定相取决于钛铝的原子比,若原子比为1:1,则最终形成TiAl相,且不同原子比区域形成的TiAl、Ti3Al可共存。     

Tensile Behavior of SiC Fiber-Reinforced γ-TiAl Composites Prepared by Suction Casting

The process of preparing SiC fiber-reinforced y-TiAl composites by the conventional methods is difficult and complicated due to the high reactivity,high melting point and poor deformability of y-TiAl alloys.In this work,suction casting,a promising method for preparing SiC_f/TiAl composite,had been attempted.In the process,y-TiAl alloy melt was introduced rapidly into a mold within pre-arranged fibers that were coated with additional layer of titanium alloy.This simple method successfully prevented serious reactions between the alloy melt and the fibers which remained intact during the solidification process.The interfacial reaction layer was observed by optical microscopy,scanning electron microscopy(SEM).The interfacial reaction products were identified by transmission electron microscopy(TEM).Tensile tests of the matrix alloy and composites were performed at room temperature and 800 ℃.The results exhibited that the tensile strength of SiC_f/γ-TiAl composite was higher than that of the matrix alloy at both room temperature and 800 0 C.At room temperature,tensile strength of SiC_f/γ-TiAl composite was increased by about 7%(50 MPa),whereas a double increase in tensile strength 14%(100 MPa)was obtained at 800 ℃.The titanium alloy coating on the fiber not only prevented the serious interfacial reaction between the y-TiAl alloy melt and the SiC fiber,but also played a role in delaying the propagation of cracks in the matrix to the fiber at 800 ℃.The fracture mechanism of the composite was analyzed by fracture metallographic analysis.