Machining in composite/metal stacks: conventional vs. ultrasonically-assisted drilling

Carbon-fibre-reinforced polymer/titanium stack components possess outstanding mechanical properties such as excellent strength-to-weight ratio, high corrosion resistance, stiffness, low density and excellent fatigue properties. These mechanical advantages translate to better fuel efficiency and ener...

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Main Author: Peace Onawumi
Format: Default Thesis
Published: 2019
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Online Access:https://dx.doi.org/10.26174/thesis.lboro.8316824.v1
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spelling rr-article-83168242019-01-01T00:00:00Z Machining in composite/metal stacks: conventional vs. ultrasonically-assisted drilling Peace Onawumi (1660306) Mechanical engineering not elsewhere classified Ultrasonically Assisted Drilling (UAD) Conventional Drilling (CD) CFRP/Ti stack Control System Vibratory Parameters Composite/metal Stack Mechanical Engineering not elsewhere classified <div>Carbon-fibre-reinforced polymer/titanium stack components possess outstanding mechanical properties such as excellent strength-to-weight ratio, high corrosion resistance, stiffness, low density and excellent fatigue properties. These mechanical advantages translate to better fuel efficiency and energy saving. These hybrid materials are not only popular but also a substitute for metals in many structural applications.</div><div>Recently, a novel machining technique - ultrasonically assisted drilling (UAD) - was introduced to machine hard-to-cut materials, in which vibrations with a low amplitude, low energy and high frequency was superimposed on the drilling tool in the axial direction during the conventional drilling process. This hybrid machining technique brings along several advantages, including multi-fold reduction in forces, required to drill in difficult-to-cut materials such as glass, ceramics, CFRP or hard alloys, hence improving machinability, associated with high-quality surface finish, and meeting standards required for modern materials.</div><div>Finally, a novel control system is designed and manufactured for UAD machining technique, capable of switching between vibratory parameters for each material constituent in the CFRP/Ti stack was implemented. The development of the control system in UAD resulted in a significant reduction in the average drilling forces, both in the composite and metal phase - 33% – 88%. The developed process appeared to improve drilling in the CFRP/Ti stack, with enhanced surface quality observed, reducing (or, in some cases, eliminating) damages induced during the drilling process in comparison to CD, with a two-to-three-fold reduction in the surface roughness.</div> 2019-01-01T00:00:00Z Text Thesis 10.26174/thesis.lboro.8316824.v1 https://figshare.com/articles/thesis/Machining_in_composite_metal_stacks_conventional_vs_ultrasonically-assisted_drilling/8316824 CC BY-NC-ND 4.0
institution Loughborough University
collection Figshare
topic Mechanical engineering not elsewhere classified
Ultrasonically Assisted Drilling (UAD)
Conventional Drilling (CD)
CFRP/Ti stack
Control System
Vibratory Parameters
Composite/metal Stack
Mechanical Engineering not elsewhere classified
spellingShingle Mechanical engineering not elsewhere classified
Ultrasonically Assisted Drilling (UAD)
Conventional Drilling (CD)
CFRP/Ti stack
Control System
Vibratory Parameters
Composite/metal Stack
Mechanical Engineering not elsewhere classified
Peace Onawumi
Machining in composite/metal stacks: conventional vs. ultrasonically-assisted drilling
description Carbon-fibre-reinforced polymer/titanium stack components possess outstanding mechanical properties such as excellent strength-to-weight ratio, high corrosion resistance, stiffness, low density and excellent fatigue properties. These mechanical advantages translate to better fuel efficiency and energy saving. These hybrid materials are not only popular but also a substitute for metals in many structural applications.Recently, a novel machining technique - ultrasonically assisted drilling (UAD) - was introduced to machine hard-to-cut materials, in which vibrations with a low amplitude, low energy and high frequency was superimposed on the drilling tool in the axial direction during the conventional drilling process. This hybrid machining technique brings along several advantages, including multi-fold reduction in forces, required to drill in difficult-to-cut materials such as glass, ceramics, CFRP or hard alloys, hence improving machinability, associated with high-quality surface finish, and meeting standards required for modern materials.Finally, a novel control system is designed and manufactured for UAD machining technique, capable of switching between vibratory parameters for each material constituent in the CFRP/Ti stack was implemented. The development of the control system in UAD resulted in a significant reduction in the average drilling forces, both in the composite and metal phase - 33% – 88%. The developed process appeared to improve drilling in the CFRP/Ti stack, with enhanced surface quality observed, reducing (or, in some cases, eliminating) damages induced during the drilling process in comparison to CD, with a two-to-three-fold reduction in the surface roughness.
format Default
Thesis
author Peace Onawumi
author_facet Peace Onawumi
author_sort Peace Onawumi (1660306)
title Machining in composite/metal stacks: conventional vs. ultrasonically-assisted drilling
title_short Machining in composite/metal stacks: conventional vs. ultrasonically-assisted drilling
title_full Machining in composite/metal stacks: conventional vs. ultrasonically-assisted drilling
title_fullStr Machining in composite/metal stacks: conventional vs. ultrasonically-assisted drilling
title_full_unstemmed Machining in composite/metal stacks: conventional vs. ultrasonically-assisted drilling
title_sort machining in composite/metal stacks: conventional vs. ultrasonically-assisted drilling
publishDate 2019
url https://dx.doi.org/10.26174/thesis.lboro.8316824.v1
_version_ 1797368015117877248