Michigan Technological University Digital Commons @ Michigan Tech Dissertations, Master's Theses and Master's Reports 2016 Design for Low-Cost Gas Metal Arc Weld-Based Aluminum 3-D Printing Amberlee S. Haselhuhn Michigan Technological University, [email protected] Copyright 2016 Amberlee S. Haselhuhn Recommended Citation Haselhuhn, Amberlee S., "Design for Low-Cost Gas Metal Arc Weld-Based Aluminum 3-D Printing", Open Access Dissertation, Michigan Technological University, 2016. https://digitalcommons.mtu.edu/etdr/172 Follow this and additional works at: https://digitalcommons.mtu.edu/etdr DESIGN FOR LOW-COST GAS METAL ARC WELD- BASED ALUMINUM 3-D PRINTING By Amberlee S. Haselhuhn A DISSERTATION Submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY In Materials Science & Engineering MICHIGAN TECHNOLOGICAL UNIVERSITY 2016 © 2016 Amberlee S. Haselhuhn This dissertation has been approved in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY in Materials Science & Engineering. Department of Materials Science & Engineering Dissertation Advisor: Dr. Paul G. Sanders Committee Member: Dr. Joshua M. Pearce Committee Member: Dr. Stephen L. Kampe Committee Member: Dr. Thomas Dorin Department Chair: Dr. Stephen L. Kampe Table of Contents List of Figures ................................................................................................................... vi List of Tables .................................................................................................................. viii Preface ............................................................................................................................... ix Acknowledgements .......................................................................................................... xi Abstract .............................................................................................................................. 1 1 Gas Metal Arc Welding (GMAW) in Additive Manufacturing................................. 3 1.1 Introduction ........................................................................................................ 3 1.2 Gas Metal Arc Welding ....................................................................................... 3 1.3 3-D Printing & Additive Manufacturing .............................................................. 7 1.3.1 Subtractive vs. Additive Manufacturing ......................................................... 7 1.3.2 Methods of Printing Metal.............................................................................. 9 1.4 References ........................................................................................................ 11 2 A Low-Cost Open-Source GMAW-Based 3-D Printer............................................. 17 2.1 Description of GMAW-Based 3-D Printer ......................................................... 17 2.1.1 Basic Design .................................................................................................. 17 2.1.2 Evolution of 3-D Printer Design .................................................................... 19 2.1.3 Details of the Low-Cost Printer & 3-Axis Stage ............................................. 20 2.2 Software Toolchain & Printing of Parts ............................................................ 21 2.3 Initial Prints & Metallurgical Considerations .................................................... 22 2.4 References ........................................................................................................ 25 3 Substrate Release Mechanisms for GMAW-Based 3-D Printing ............................ 27 3.1 Abstract ............................................................................................................. 27 3.2 Introduction ...................................................................................................... 28 3.3 Hypothesis......................................................................................................... 31 3.4 Materials & Methods ........................................................................................ 32 3.4.1 Description of the Metal 3-D Printer ............................................................ 32 3.4.2 Preparation of Print Substrates .................................................................... 33 3.4.3 Printing of Samples ....................................................................................... 33 3.4.4 Sample Testing & Analysis ............................................................................ 35 3.5 Results ............................................................................................................... 41 3.5.1 Dimensional Validation & 3-D Printed Part Inspection ................................ 41 3.5.2 Specimen-Substrate Impact Energy .............................................................. 42 3.5.3 Specimen Porosity ........................................................................................ 44 3.5.4 Specimen Microstructure ............................................................................. 45 3.5.5 Specimen Hardness ....................................................................................... 47 3.5.6 Ultrasonic Modulus ....................................................................................... 48 3.6 Discussion.......................................................................................................... 50 3.7 Conclusions ....................................................................................................... 58 3.8 References ........................................................................................................ 59 iii 4 Structure-Properties Relationships of Common Aluminum Weld Alloys Utilized as Feedstock for GMAW-Based 3-D Printing ........................................................... 65 4.1 Abstract ............................................................................................................. 65 4.2 Introduction ...................................................................................................... 66 4.3 Background ....................................................................................................... 67 4.4 Hypotheses ....................................................................................................... 70 4.5 Materials and Methods ..................................................................................... 70 4.5.1 Description of the Metal 3-D Printer ............................................................ 70 4.5.2 Printing of Test Specimens............................................................................ 71 4.5.3 Specimen Machining & Analysis ................................................................... 73 4.6 Results ............................................................................................................... 77 4.6.1 As-Printed Dimensions & Porosity ................................................................ 77 4.6.2 Influence of Specimen Location & Orientation on Mechanical Properties .. 79 4.6.3 Average Mechanical Properties .................................................................... 82 4.6.4 Microstructural Analysis ............................................................................... 87 4.7 Discussion.......................................................................................................... 91 4.7.1 As-Printed Dimensions & Porosity ................................................................ 91 4.7.2 Influence of Specimen Orientation on Mechanical Properties .................... 93 4.7.3 Microstructural Analysis ............................................................................... 95 4.7.4 Mechanical Properties .................................................................................. 96 4.8 Conclusions ....................................................................................................... 99 4.9 References ...................................................................................................... 100 5 Aluminum Alloy Development for GMAW-Based 3-D Printing ........................... 108 5.1 Abstract ........................................................................................................... 108 5.2 Introduction .................................................................................................... 109 5.2.1 Eutectic Modification Strategies in Hypoeutectic Al-Si Alloys .................... 109 5.2.2 Grain Refinement in Hypoeutectic Aluminum-Silicon Alloys ..................... 112 5.2.3 Alloying Considerations for Welding .......................................................... 113 5.2.4 The Role of Wedge Castings in Alloy Development .................................... 115 5.3 Hypotheses ..................................................................................................... 116 5.4 Materials & Methods ...................................................................................... 117 5.4.1 Description of Permanent Mold ................................................................. 117 5.4.2 Alloy Melting & Pouring .............................................................................. 118 5.4.3 Alloy Testing & Analysis .............................................................................. 120 5.5 Results ............................................................................................................