Thesis
Investigation of drilling performance on Ti-64AL-4V and carbon fiber reinforced plastic (CFRP)-Ti stack when using super-hard ceramic coated tools
Washington State University
Master of Science (MS), Washington State University
2017
Handle:
https://hdl.handle.net/2376/104437
Abstract
Advanced materials are an increasing trend in use in a variety of industries. In aerospace, materials impact virtually all aspects of an aircraft which include cost, design performance, as well as, operation and consumption. Light, stiff, strong, durable, available, and cost-efficient materials are key demands in aerospace applications. This streamlines the use of fiber reinforced plastics (FRP) and superalloys such as titanium (Ti). With the ability to tailor specific mechanical properties with efficient cost and weight, FRPs like Carbon Fiber Reinforced Plastics (CFRP) are highly desired in aerospace applications. Ti alloys, especially Ti6Al4V, have been extensively used due to many properties like high strength-to-weight ratio. When combining the two materials, CFRP-Ti into a stack provides paramount material properties that are not achievable with a single material. In the machining process of advanced materials, many difficult problems may be encountered, especially when dissimilar materials are combined into a stack. Based on few successes with coated drills reported in the literature, this thesis makes a comparative study of drilling Ti and CFRP-Ti stack with several super hard coated drills with the coatings of Diamond-like-Carbon (DLC), AlMgB14 (BAM) and nanocomposite AlCrSiN and compared the results with uncoated carbide and high speed steel cobalt (HSS-Co) drills. Drilling forces acquired from a dynamometer during the drilling process and tool images from a scanning electron microscope and a confocal laser microscope were used to assess the wear progress of each drill qualitatively and quantitatively.Out of machining parameters, feed rate mostly affects the machinability of Ti64. DLC coatings might not be suitable for HSS-Co drills due to cobalt content. Altering the cutting edge can have a negative effect on tool life. Overall, DLC, BAM, and AlCrSiN coated tungsten carbide drills improved the machinability in Ti only and CFRP-Ti stack drilling compared to uncoated tungsten carbide drill. BAM performed best in Ti only drilling which produced 100 holes. AlCrSiN coated tungsten carbide drills experienced outstanding performance when drilling CFRP-Ti stack which produced 80 holes, demonstrating tool life enhancement.
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Details
- Title
- Investigation of drilling performance on Ti-64AL-4V and carbon fiber reinforced plastic (CFRP)-Ti stack when using super-hard ceramic coated tools
- Creators
- Vadim Voznyuk
- Contributors
- Dave Kim (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525284001842
- Language
- English
- Resource Type
- Thesis