钕化物颗粒增强钛基复合材料的组织和性能

研究了原位生成的钕化物颗粒增强Ｔｉ－６Ａｌ－４．５Ｓｎ－３．５Ｚｒ－０．５Ｍｏ－０．７Ｎｂ－０．３５Ｓｉ－０．０６Ｃ（ｗｔ％）复合材料的组织和性能。颗粒呈球形或椭球形，平均颗粒粒度为～７μｍ，间距为～４０μｍ。颗粒在基体上均匀分布，它的微观结构由非常细小、结构复杂的多晶体组成，主要含有钕、锡和氧元素。测试了复合材料的室温拉伸、高温拉伸、高温持久和蠕变等力学性能。经１０６５℃／０．５ｈ／ＦＡＣ＋１０００℃／１ｈ／ＡＣ＋７００℃／４ｈ／ＡＣ热处理后，材料具有较好的力学性能。拉伸和持久断口均属于典型延性断裂。一些颗粒的内部存在裂纹，未发现裂纹由颗粒向基体传播。     

钛合金的切削加工工艺分析

结合钛合金的性能特点,分析了影响钛合金切削加工的主要因素,并提出解决方法。     

Ti6A14V的激光涂层

 <正> 1.引言 钛和钛合金的抗磨性差且难于润滑,为改善其抗磨性,尝试过许多表面处理方法,如氮化,氰化、在碳酸钾中控制氧化、电镀和硼化等,但是共同缺点是所得涂层太薄及处理过程不同程度地损害基体。目前工程上需要同基体结合力强且无缺陷的厚涂层。激光涂层处理对基体影响小,涂层质量高且厚度易调整,能在很大程度上满足工程上要求,所以激光涂层很有发展前途。     

TiAlB合金中初生TiB2的形貌及其形成机理

用原位自生法制备了Ti-53Al-xB合金,并用X射线衍射仪、扫描电镜对合金的相组成和微观组织进行了研究.结果表明:该合金主要由TiAl和TiB2两相组成;初生TiB2呈六面棱柱状,在TiAlB合金凝固过程中,Al原子富集在初生TiB2固-液界面前沿,导致固-液界面上B原子过饱和度不均匀性增加,使固-液界面变得不稳定, 从而在TiB2(0001)面上产生凸台或柱棒状分枝;分枝的各晶面取向与母体的取向一致,在初生TiB2(0001)面的凸台状或柱棒状分枝上能观察到清晰的台阶.     

焊接工艺对钛合金焊接接头冲击韧性的影响

介绍了俄罗斯对钛及其钛合金焊接接头冲击韧性最大值的影响因素的研究工作,以对相关航空研究作参考作用。     

Tool Life and Surface Integrity in High-speed Milling of Titanium Alloy TA15 with PCD/PCBN Tools

Titanium alloys are widely used in aeronautics that demand a good combination of high strength, good corrosion resistance and low mass. The mechanical properties lead to challenges in machining operations such as high process temperature as well as rapidly increasing tool wear. The conventional tool materials are not able to maintain their hardness and other mechanical properties at higher cutting temperatures encountered in high speed machining. In this work, the new material tools, which are polycrystalline diamond (PCD) and polycrystalline cubic boron nitride (PCBN) tools, are used in high-speed milling of Ti-6.5Al-2Zr-1Mo-1V (TA15) alloy. The performance and wear mechanism of the tools are investigated. Compared to PCBN tool, PCD tool has a much longer tool life, especially at higher cutting speeds. Analyses based on the SEM and EDX suggest that attrition, adhesion and diffusion are the main wear mechanisms of PCD and PCBN tools in high-speed milling of TA15. Oxidation wear is also observed at PCBN tool/workpiece interface. Roughness, defects, micro-hardness and microstructure of the machined surface are investigated. The recorded surface roughness values with PCD/PCBN tools are bellow 0.3 μm at initial and steady cutting stage. Micro-hardness analysis shows that the machined surface hardening depth with PCD and PCBN tools is small. There is no evidence of sub-surface defects with PCD and PCBN tools. It is concluded that for TA15 alloy, high-speed milling can be carried out with PCD/PCBN tools.     

钛合金TA10焊接技术在燃料储罐上的应用

为了摸索TA10钛合金的焊接工艺技术,通过大量的焊接工艺试验及分析,拟定合理的焊接工艺参数,同时根据TA10钛合金的焊接特点,设计了大量的气体保护装置,将焊缝与热影响区在焊接及焊后冷却过程中温度高于300℃的区域置于氩气的良好保护之下,经过焊接工艺评定试验验证,最终确定了钛合金TA10焊接最佳的焊接工艺规范参数,焊缝表面的保护效果、氧化程度、焊缝X射线检测结果、熔敷金属化学成分及焊缝力学性能等各项技术指标均达到了设计要求,保证了产品的焊接质量。     

TC4钛合金超音频直流脉冲TIG焊

首先对超音频直流脉冲TIG焊的特点进行了介绍,重点分析了的峰值电流、脉冲频率等关键工艺参数对超音频直流脉冲TIG焊电弧轴向等离子流力的影响规律.采用频率不同的几组超音频直流脉冲TIG焊工艺及常规直流TIG焊工艺分别焊接了2.5mm厚的TC4钛合金.用X-射线探伤检测焊缝中的气孔缺陷,根据检测结果,分析了超音频直流脉冲T...     

双层板激光焊接/ 超塑成形数值模拟及工艺研究

选取TC4 钛合金四层板加强结构中双层板为研究对象,采用激光穿透焊接工艺代替传统超塑成

形/ 扩散连接(SPF/ DB)工艺中涂止焊剂连接。借助ABAQUS 有限元分析软件对超塑成形过程进行分析,得到

优化的压力-时间(p-t)曲线,作为双层板超塑成形过程的气压加载曲线,进行实验验证。结果表明:成形后零

件壁厚分布均匀,焊缝处无撕裂现象,与有限元模拟结果保持一致;用此新工艺代替传统SPF/ DB 工艺中的止

焊剂具有可行性。