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Full-Text Articles in Engineering

Comparison Of Intrusive And Non-Intrusive Methods For Corrosion Monitoring Of Fuel Processing Systems, Armando Jacob Espinoza, Thomas Conner Field Jun 2017

Comparison Of Intrusive And Non-Intrusive Methods For Corrosion Monitoring Of Fuel Processing Systems, Armando Jacob Espinoza, Thomas Conner Field

Materials Engineering

This presentation contains an assessment of the best overall corrosion monitoring device, intrusive or non-intrusive, for use in the petrochemical industry. Corrosion in the petrochemical industry is a large issue because it causes a deterioration of pipe integrity in fuel processing systems. A reduction of pipe wall integrity due to corrosion could result in a leak or an explosion of fuel processing lines since those systems function at high pressures. The use of corrosion monitoring systems in the petrochemical industry helps to detect early signs of corrosion prior to failure so that proper maintenance can be performed to prevent catastrophe. …


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 …


Kinked Tensile Behavior Of Cold Worked Nitinol, Grant R. Caraway, Samuel J. Canovas Jun 2017

Kinked Tensile Behavior Of Cold Worked Nitinol, Grant R. Caraway, Samuel J. Canovas

Materials Engineering

To characterize the decrease in ductility caused by an induced stress concentration as a function of various levels of cold work and heat treatment, Nitinol medical guide wires with a .004″ diameter were tested using both a standard, straight tensile test and a modified, bent tensile test. The ratio of the two break loads (bent:straight) for identically processed samples was used as a proxy for measuring the ductility of the guide wires: the higher the ratio, the more ductile the sample. The average break load ratio as a function of increased cold work, decreased from 1.27 to 0.91 for the …


Effect Of Composition And Build Direction On Additively Manufactured Hastelloy X Alloys, Justin A. Spitzer, Jeffrey T. Schloetter, Sarah Zerga Jun 2017

Effect Of Composition And Build Direction On Additively Manufactured Hastelloy X Alloys, Justin A. Spitzer, Jeffrey T. Schloetter, Sarah Zerga

Materials Engineering

Microcracking has caused premature failure and reduction in properties in additively manufactured (AM) Hastelloy X. The purpose of this research is to meet or exceed the mechanical properties of wrought Hastelloy X by modifying the composition and build direction of Hastelloy X manufactured using Direct Metal Deposition (DMD). Tensile testing, scanning electron microscopy (SEM), and metallography were performed on the samples. ANOVA was used to analyze the dependence that the properties had on build direction and composition. The nominal composition wrought samples had a yield strength of 310.1 MPa and a 60.79% Elongation. Alloy P60-X18 in a horizontal build had …


Straightening Of Investment Casting Ni-Based Superalloys, Silvia Squillaci, Janessa Cabrera Jun 2017

Straightening Of Investment Casting Ni-Based Superalloys, Silvia Squillaci, Janessa Cabrera

Materials Engineering

Samples belonging to four different designs of afterburner flaps, available in the as-cast, solutionized and aged conditions, underwent 4-point bend testing to fracture to investigate straightening. The average maximum load values of the second design samples in the as-cast, solutionized and aged conditions were respectively 33 kN, 29 kN and 27 kN. Regarding the fourth design samples, the average maximum load for the as-cast, solutionized and aged conditions were respectively 23 kN, 28 kN, and 25 kN. The other parameter measured during testing was the maximum extension at fracture. All as-cast samples belonging to the second design fractured at values …


Tensile Properties Of High-Strength Connecting Rod Bolts, Leland K. Lam Jun 2017

Tensile Properties Of High-Strength Connecting Rod Bolts, Leland K. Lam

Materials Engineering

Oliver Racing Parts (ORP) is looking to optimize the manufacturing process for high-strength connecting rod bolts. A high yield strength is desired for the bolts because deformation would result in a loss of engine performance. A high tensile strength is also necessary to prevent catastrophic failure if deformation occurs. A high ductility as a proxy for toughness is attractive for resisting crack nucleation and growth during cyclic loading. Bolts were made of MP35N, a nickel-cobalt multiphase alloy; MLX-17, a precipitation hardenable stainless steel; 8740, a low alloy steel; and H11, a chromium hot-work tool steel. The temperature of the most …


Characterization Of Slm Printed 316l Stainless Steel And Investigation Of Microlattice Geometry, Finley H. Marbury Jun 2017

Characterization Of Slm Printed 316l Stainless Steel And Investigation Of Microlattice Geometry, Finley H. Marbury

Materials Engineering

The goal of this project was firstly to characterize Cal Poly’s SLM printed 316L stainless steel. SEM analysis showed Cal Poly’s as-printed 316L material to have a cellular dendritic microstructure containing mostly austenite and a small amount of δ-ferrite. After being heat treated to eliminate warp, its yeild and ultimate tensile strength were on par with the literature, however higher modulus and lower elongation were observed. XRD analysis confirmed residual stresses in the material, and that grains are preferentially oriented in both heat treated and non heat treated samples. The amount of porosity in the material was found to be …


Predicting Service Life Of 347 Stainless Steel Pipes By Carburization Rate Measurement, Tyler L. Sura Jun 2017

Predicting Service Life Of 347 Stainless Steel Pipes By Carburization Rate Measurement, Tyler L. Sura

Materials Engineering

Chevron Corporation and other refiners face challenges predicting the service life of piping in coker furnaces. This is largely due to a build up coke on a single surface of the piping. This coke build up results in carbon penetration into the surface of the 347 stainless steel used for the pipes. Carbon penetration can lead to degradation of the surface and ultimately, the failure of the pipe. Current modeling software has difficulty predicting the influence of sulfur on the carbon penetration rate. This study aims to provide a baseline for further study into the subject. The carbon penetration rate …


Development Of Low Cost Braze Alloys For Aerospace Applications, Alyssa M. Elliott, Sandy Babich, Blake Whitmee Jun 2017

Development Of Low Cost Braze Alloys For Aerospace Applications, Alyssa M. Elliott, Sandy Babich, Blake Whitmee

Materials Engineering

Non-precious metal braze alloys can help lower the cost of brazing, which is a commonly-used joining process in the aerospace industry. A-286, a stainless steel superalloy, and Inconel© 718, a nickel-based superalloy, are both commonly used alloys at Aerojet Rocketdyne. Both alloys were brazed into butt joints using nickel-based braze alloys: AMS 4776, 4777, and 4778. The brazed samples were machined into a modified version of the ASTM E8 subsize specimen samples and tensile tested to compare the strength and calculated elongation of the brazed samples to the base metals’ properties. All of the brazed samples fractured at the joint, …


Preliminary Investigations Into Selective Laser Melting, David Takeo Otsu Jun 2017

Preliminary Investigations Into Selective Laser Melting, David Takeo Otsu

Master's Theses

Selective laser melting is a promising metallic additive manufacturing process with many potential applications in a variety of industries. Through a gracious donation made by Lawrence Livermore National Laboratory, California Polytechnic State University received and installed an SLM 125 HL selective laser melting machine in February 2017. As part of the initial setup effort, a preliminary machine verification study was conducted to evaluate the general print quality of the machine with default parameter settings. Coincidentally, the as-printed microstructure of SLM components was evaluated through nil strength fracture surface examination, an alternative to conventional polish-and-etch metallography. A diverse set of components …