Welding of Single and Polycrystal Nickel Superalloys to Aluminides Based Aero-engine and Power Generation Turbine Materials by New and Emerging Joining Technologies

用于航空发动机涡轮的传统高温合金已经达到了其高温应用极限，具有更高高温性能的TiAl和Ni3Al基合金正在开发中。它们的使用需要焊接来制造和修理航空涡轮部件。这些材料还需要与传统的Ni高温合金结合。镍高温合金和金属间合金都极难焊接，但由于其化学和微观结构的显着差异，将它们连接在一起变得更具挑战性。因此，所提出的研究的长期目标是获得使用新兴焊接工艺连接当前和新一代铝基航空涡轮材料的科学和技术的基本知识，以制定可靠的连接程序。短期内，本研究将研究多晶in738和单晶CSMX 486 Ni高温合金与单晶NI3AL基合金ic6焊接时的焊缝开裂问题，并开发无裂纹焊缝的方法。这将通过使用各种填充合金的焊接实验以及在激光焊接、激光电弧复合焊接和采用各种工艺参数的线性摩擦焊接过程中的焊前和焊后加热来实现。与以往一样，焊接实验将在Standard Aero进行。公司。温尼伯和蒙特利尔NRC航空航天制造技术中心。焊接裂纹和焊缝的微观结构将通过申请人实验室可用的最先进的微观结构表征设备进行评估，以确定工艺参数和填充合金成分对焊接质量的作用。然后通过数值模拟优化工艺参数和填充合金成分，并通过进一步的实验验证所开发的模型。拟培养硕士研究生2名，博士研究生2名。这项研究将有助于开发基于Ni和Ti铝化物的新兴航空涡轮材料的焊接工艺，并有助于提高加拿大航空航天公司在世界市场上的竞争地位。

Conventional high-temperature superalloys used in aero-engine turbines have reached their upper temperature application limit, and TiAl and Ni3Al based alloys with a higher high temperature capability are being developed. Their use would require them to be welded to fabricate and repair aero-turbine components. These materials would also need to be joined to conventional Ni superalloys. Both, Ni superalloys and Intermetallic alloys are extremely difficult to weld, but joining them together becomes even more challenging due to a significant disparity in their chemistry and microstructure. Therefore, the LONG-TERM objective of the proposed research is to obtain a basic knowledge of the science and technology of joining of current and new generation aluminide based aero-turbine materials using emerging welding processes to develop reliable joining procedures. In the SHORT-TERM the research will investigate the weld cracking issues during welding of polycrystalline IN 738 and single crystal CSMX 486 Ni superalloys to single crystal NI3AL based alloy IC 6, and develop methods to produce crack-free welds. This will be achieved through welding experiments using various filler alloys and pre and post-weld heating during laser welding, laser-arc hybrid welding and linear friction welding using various process parameters. As in the past, the welding experiments will be performed at Standard Aero. Inc. Winnipeg, and NRC Aerospace Manufacturing Technology Centre, Montreal. Weld cracking and microstructures of the welds will be evaluated, by state-of-the-art microstructure characterization facilities available in applicant's laboratory, to determine the role of process parameters and filler alloy composition on quality of welds. Process parameters and filler alloy compositions will then be optimized through numerical modeling, and the developed model will be validated by further experimentation. It is planned to train 2 M.Sc. and 2 PhD students through the proposed research. This research will help develop welding procedures for Ni and Ti aluminide based emerging aero-turbine materials, and help enhance Canadian Aerospace companies' competitive position in the world markets.