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

传统的航空发动机涡轮用高温合金已经达到了使用温度的上限，具有更高高温性能的TiAl和Ni 3Al基合金正在开发中。它们的使用将需要焊接它们来制造和修理航空涡轮机部件。这些材料还需要与传统的镍超合金结合。镍超合金和金属间合金都非常难以焊接，但由于它们的化学和微观结构存在显著差异，将它们连接在一起变得更具挑战性。因此，拟议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化物基航空涡轮材料的科学和技术的基本知识，以开发可靠的连接程序。在短期内，研究将调查多晶IN 738和单晶CSMX 486 Ni高温合金焊接到单晶Ni 3Al基合金IC 6期间的焊接裂纹问题，并开发产生无裂纹焊缝的方法。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-电弧混合焊接和使用各种工艺参数的线性摩擦焊接期间的焊前和焊后加热来实现。与过去一样，焊接实验将在标准航空公司进行。Inc.温尼伯和蒙特利尔NRC航空航天制造技术中心。将通过申请人实验室中现有的最先进的微观结构表征设施来评估焊缝的焊接裂纹和微观结构，以确定工艺参数和填充合金成分对焊缝质量的作用。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。计划通过该研究培养2名硕士生和2名博士生。这项研究将有助于开发基于镍和钛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.