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Engineering Commons

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Materials Science and Engineering

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California Polytechnic State University, San Luis Obispo

Theses/Dissertations

2017

Materials Engineering

Articles 1 - 3 of 3

Full-Text Articles in Engineering

Characterization Of The 15-5 Stainless Steel Electric Discharge Machining Recast Layer, Julian R. Lohser, Rhys W. Gilmore Jun 2017

Characterization Of The 15-5 Stainless Steel Electric Discharge Machining Recast Layer, Julian R. Lohser, Rhys W. Gilmore

Materials Engineering

Electric discharge machining (EDM) is a non-conventional machining process that is used for tough, hard materials or materials that require no tool force. Wire EDM produces a recast layer and heat-affected zone as a result of rapid melting and quenching at the surface of the cut. A secondary machining operation has been required to remove this layer. Previous estimates of the depth of the recast layer are likely too conservative due to improvements in the technology; therefore, the goal of this study is to characterize and more accurately investigate the size of the layer. Two EDM machine parameters, voltage and …


Mechanical Testing Protocol For Characterizing Composite Lamina Pre-Pregs, Kenneth Blain Ainslie, Joshua Gustav Brinkmann Jun 2017

Mechanical Testing Protocol For Characterizing Composite Lamina Pre-Pregs, Kenneth Blain Ainslie, Joshua Gustav Brinkmann

Materials Engineering

Zodiac Aerospace currently employs finite element analysis (FEA) computer models to predict the material behavior of its composite products. The objective of this project was to develop a testing protocol for obtaining detailed material property data to use in these FEA models. With accurate material data, FEA models can reduce the need for expensive physical testing and achieve timely troubleshooting when testing complex components. The specific material characterized in this project was an 8-satin weave fiberglass phenolic pre-preg used as the facesheet material in many of Zodiac’s sandwich panel composites. The developed testing protocol involved mechanical testing of lamina and …


Invariant-Based Method For Improving Efficiency Of Mechanical Testing In Aerospace Certification Of Carbon Fiber-Epoxy Composites, Alyssa Rina Gruezo, Erika Gabrielle Hansen Jun 2017

Invariant-Based Method For Improving Efficiency Of Mechanical Testing In Aerospace Certification Of Carbon Fiber-Epoxy Composites, Alyssa Rina Gruezo, Erika Gabrielle Hansen

Materials Engineering

The current challenge with qualification of carbon fiber composites in the aerospace industry would be the low efficiency of testing hundreds of samples. The Trace Theory strives to streamline the qualification process by utilizing a material’s Trace to predict properties of composites using Excel programs and basis data. To test this theory, predicted properties from the program, QuickLam, were compared to experimental data. Unidirectional 0° (T1), unidirectional 90° (T2), quasi-isotropic (T3), and hard quasi-isotropic (T4) laminates were made using HexTowR carbon fiber and TC250 resin provided by TenCate Advanced Composites. Tensile and compression tests were done according to ASTM D3039 …