Abstract: In this era of constantly rising demand for increased fuel economy, it is imperative to develop ‘green’ manufacturing technologies and solutions in this direction. The broad focus is on to reduce the carbon footprint of humans by a significant amount while improving the performance of the process and the resulting product. Metallic materials have been the backbone of industry, and advanced lightweight materials are essential, especially for transportation industries to improve fuel economy while improving safety and performance. Steels, owing to their attractive properties, recyclability, matured state of the art, and relatively low cost, have historically been the preferred choice for structural application in automotive industry. However, it is clear that a single material cannot fit all applications. Multi-material concept including a hybrid of light metals is now a trend for the automotive industry. Joining of materials is a critical step in any manufacturing environment. Modern day vehicle contains 15-20 types of material. Appropriate joining of these parts is essential to the high performance of the structure.
The focus of this talk will be on research on friction stir based welding technologies applied to multi-material system consisting of various alloy systems for numerous aerospace and automotive applications. Conventional joining techniques have been used for decades and for certain materials, have several disadvantages as compared to solid-state joining techniques. A relatively new joining technology (friction stir welding – FSW) has gained significant traction. As a part of this work, the process was applied to high strength precipitation strengthened aluminum alloys to improve the joint strength and reduce the carbon emission of aerospace vehicles. Various aspects such as, effect of alloy chemistry, thermal cycle, processing parameters, post weld heat treatment, etc. were studied. An innovative derivative of FSW was also applied to manufacture high performance and lighter dissimilar material combinations. Furthermore, as the industry is rapidly moving toward additive based manufacturing processes, friction stir based additive solution was also explored to address the metallurgical drawback of fusion based additive processes. As a part of this presentation, experimental result from FSW based multi-material approach to light-weight structure will be discussed.
Bio: Harpreet Sidhar earned his PhD from department of Materials Science and Engineering at University of North Texas. His research during PhD was focused on joining of similar and dissimilar material combinations for light-weighting applications in aerospace and automotive industry. Before joining Michigan State University, Harpreet also worked as a postdoctoral fellow at Florida International University where he focused on materials science solutions to sea level rise.