Direct observation of layer growth at interface of dissimilar friction weld joints - Modeling of reliability for dissimilar joint -

直接观察异种摩擦焊接接头界面处的层生长 - 异种接头可靠性建模 -

• 批准号: 10650700
• 负责人: FUJI Akiyoshi
• 金额: $ 2.3万
• 依托单位: Kitami Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650700/
• 关键词: friction welding; dissimilar joint; intermetallic compound; intermediate layer; titanium; aluminium (aluminum); direct observation; チタニウム(チタン、Ti); アルミニウム(アルミ、Al)

It is well-known that the dissimilar friction joining process alters the metallurgical and mechanical properties of material immediately adjacent to the bondline. The present paper examines the the joining process of pure Ti/pure Al dissimilar friction weld was clarified, and the layer growing by post-weld heat treatment (PWHT) at interface of the joint was carried out by direct observation with a high temperature optical microscope.(1) Joining process : The joining area almost started from joint center axis or half radius location to periphery of weld joint in spite of joint diameter. This phenomena was different from that of similar friction weld joints.(2) Layer growing :a) The width of intermediate layer (intermetallic compound phase) that occurs at the joint interface by PWHT saturated up to approximately 100 μm after long time heating in spite of location of joint interface. It was consisted with AlィイD23ィエD2Ti, and grew mainly from Al substrate to Ti one. The crack occurred at the interface of AlィイD23ィエD2Ti and Al substrate.b) Layer growing at periphery region was faster than that at center axis region.c) The activation energies of phase formation at center axis, half a radius and periphery regions were approximately 93.2, 96.1 and 77.0kJ/mol, respectively. This reason was thought as follow : the width of the intermediate layer at periphery region produced during friction welding was much wider than that of center region. Therefore, the mutual diffusion between Ti and Al substrates at periphery was easier than at center region.d) The difference of activation energy was decreased when friction time increased from 2s to 5s. This reason is thought that the difference of phase growing speed was minimized because heat generation reached enough by long friction time.

众所周知，异种材料摩擦连接过程会改变紧邻胶层的材料的冶金和机械性能，本文研究了纯钛/纯铝异种材料摩擦焊缝的连接过程，并通过后生长层进行了研究。 - 通过高温光学显微镜直接观察进行接头界面的焊接热处理（PWHT）。（1）连接过程：连接区域几乎从接头中心轴线或半半径位置开始到周边尽管接头直径不同，但这种现象与类似的摩擦焊接接头不同。(2) 层生长：a) PWHT 饱和后在接头界面处出现的中间层（金属间化合物相）的宽度。长时间加热后100μm，无论接头界面位置如何，均以AlD23D2Ti为起始，主要从Al基体向Ti基体生长，裂纹发生在界面处。 Al D23 D2Ti 和 Al 基体。b) 外围区域的层生长速度快于中心轴区域。c) 中心轴、半半径和外围区域的相形成活化能分别约为 93.2、96.1 和 77.0kJ/分别认为原因如下：摩擦焊接过程中产生的外围区域的中间层的宽度比中心区域的宽度宽得多。周围的Ti和Al基体之间的相互扩散比中心区域更容易。d)当摩擦时间从2s增加到5s时，活化能的差异减小。这个原因被认为是由于热量而使相生长速度的差异最小化。通过长摩擦时间达到足够的发电量。