Weldability study in dissimilar microwelding of nickel-titanium alloys

异种材料的焊接和连接，如镍钛合金与其他合金的焊接和连接，仍然是制造医疗器械的主要挑战之一。主要问题是金属间化合物(IMCs)的形成，这通常对联合性能和性能有害。 目前的提案寻求与Baylis Medical合作，对用于导管导丝和其他医疗设备的钛合金或不锈钢的激光不同种类微焊接进行系统研究，旨在提高对贱金属化学和条件的影响，以及激光焊接工艺参数和配置对IMC形成及其对机械性能的影响的了解。特别计划研究和开发使用夹层来限制IMC的形成。虽然这个项目将主要研究激光焊接，但将探索其他焊接工艺，如电阻微焊，作为形成固态焊缝的替代方案，从而可能完全消除IMC。 拟议的工作将加强加拿大在医疗器械和其他微系统的设计和制造领域的地位，特别是先进材料的加入。具体地说，在这项拟议工作中开发的知识和工程诀窍将对不同材料连接的科学和技术作出重大贡献(在期刊和会议出版物方面)。它还将提供工程指南，以优化工艺条件，并增加医疗器械设计和制造的灵活性。这项工作还将促进不同层次(本科生和研究生，以及博士后研究员)焊接和连接专业知识的发展，以满足制造业的需要。

Welding and joining of dissimilar materials, such as Nickel-Titanium (NiTi) alloys to other alloys, remains as one of the main challenges in manufacturing medical devices. The main issue is the formation of intermetallic compounds (IMCs) that is normally detrimental to the joint properties and performance. The current proposal seeks, in collaboration with Baylis Medical, a systematic study of laser dissimilar microwelding of NiTi alloys to Ti alloys or stainless steel for catheter guidewire and other medical device applications aiming to improve understanding of the effects of base metal chemistry and conditions, and laser welding process parameters and configurations on the IMC formation and its influence on mechanical properties. It is especially planned to investigate and develop the use of interlayers to limit IMC formation. While this project will study primarily laser welding, other welding processes such as resistance microwelding will be explored as alternatives to form solid-state welds so IMCs might be completely eliminated. The proposed work would strengthen Canada's position in the fields of design and fabrication of medical devices and other microsystems in general, and advanced materials joining in particular. Specifically, the knowledge and engineering know-how developed in this proposed work will make significant contributions (in terms of journal and conference publications) to the science and technology of dissimilar materials joining. It will also provide engineering guidelines to optimize the process conditions and to increase flexibility for design and fabrication of medical devices. This work will also foster development of welding and joining expertise at different levels (undergraduate and graduate students, and post-doctoral fellows), as needed by manufacturing industries.