Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 9 of 9

Full-Text Articles in Engineering

Characterization And Analysis Of Low Room Temperature Ductility Nickel-Based Superalloy 718 Plus For Aircraft Engine Forgings, Jonathon Bracci Jun 2012

Characterization And Analysis Of Low Room Temperature Ductility Nickel-Based Superalloy 718 Plus For Aircraft Engine Forgings, Jonathon Bracci

Materials Engineering

Schlosser Forge Co. forges low pressure turbine (LPT) cases from the nickel based superalloy 718 Plus using the ring rolling forging process. Schlosser has been experiencing low room temperature ductility problems in a number of their 718 Plus LPT cases. LPT cases are required to pass a 4D tensile test at room temperature with a minimum of 15 percent elongation. The ductility problem was reduced by increasing the forging temperature from 1825˚F to 1850˚F. Analysis was performed on 718 Plus samples taken from forged LPT cases that failed the room temperature ductility requirement and ones that passed the requirement. The …


Effects Of Beta Stabilizers On Quench Delay Susceptibility Of Ti-6al-4v, Kyle Logan Jun 2012

Effects Of Beta Stabilizers On Quench Delay Susceptibility Of Ti-6al-4v, Kyle Logan

Materials Engineering

Tensile samples of Titanium 6Al-4V (Ti-6Al-4V) were machined from forgings containing rich and poor amounts of beta stabilizers in their compositions. The tensile samples were each heat treated two times. In the first round of heat treatments, the samples were either beta solution treated (BST), or solution treated (ST). Each sample was water quenched with varying quench delays of 10, 20, and 30 seconds. BST treated specimens were then overaged at 1350°F for 2 hours and air cooled (BSTOA); while the ST treated samples were aged at 990°F for 6 hours and air cooled (STA). Following heat treating, the tensile …


Discontinuous Grain Boundaries Of Forged René 41, Steven Crump Jun 2012

Discontinuous Grain Boundaries Of Forged René 41, Steven Crump

Materials Engineering

Forged components must pass a grain size specification (grain size, distribution) for acceptance in an application. The varying amounts of plastic deformation during forging can lead to abnormally large recrystallized grain sizes in certain regions of the part, which will not pass specification. The question exists whether these abnormally coarse grains are truly comprised of poly crystalline fine grains with grain boundaries resistant to etching techniques. To investigate this abnormal grain size effect, a cross section of a forged René 41 nickel-based superalloy aircraft engine ring was cut and sectioned into six segments. Those segments were then prepared for microstructural …


Effect Of Heating Temperature, Heating Time And Initial Microstructure On Recrystallization Of Waspaloy During Heating For Forging, Marissa Hill Jun 2012

Effect Of Heating Temperature, Heating Time And Initial Microstructure On Recrystallization Of Waspaloy During Heating For Forging, Marissa Hill

Materials Engineering

A fine, uniform grain size is required for creep limited Waspaloy in aircraft engine applications. Upon heating, Waspaloy does not always recrystallize in a uniform manner resulting in occasional large grains with a majority of the grains meeting the grain size requirements. Waspaloy’s microstructure was analyzed with different heat treatments and in the as-forged condition. The strengthening mechanism is the gamma prime phase. The gamma prime solvus temperature is 1908°F so the different heat treatments were determined around that temperature, as well as the forging temperature range of 1800-2150°F. At the 1850°F heat treatment, the microstructure recrystallized with small grains, …


Morphology And Roughness Of Al2o3 On Ferritic Stainless Steel Foil For Diesel Catalytic Converter Applications, Megan Butala Jun 2012

Morphology And Roughness Of Al2o3 On Ferritic Stainless Steel Foil For Diesel Catalytic Converter Applications, Megan Butala

Materials Engineering

The improved thermal properties of metal-substrate catalytic converters enable effective catalysis sooner after ignition than traditional ceramic monoliths, resulting in less harmful emissions. ACAT Global, a manufacturer of stainless steel catalytic converters, uses ferritic stainless steel substrates for low temperature catalytic converters for diesel automobiles. Production begins with an oxidizing heat treatment to increase surface roughness. The success of the second production step, the application of catalyst-containing ceramic slurry (washcoat), depends on the surface roughness that results from oxidation. Formation of the primary oxide of interest, alumina (Al2O3), is controlled by the stainless steel foil composition, …


Microstructural Characterization Of Ti-6al-4v And Its Relationship To Sample Geometry, Blake Gaspar Jun 2012

Microstructural Characterization Of Ti-6al-4v And Its Relationship To Sample Geometry, Blake Gaspar

Materials Engineering

A problem exists with a part produced by forging made by Shultz Steel of Ti-6Al-4V in the variance of properties throughout the part. There is one specific region that exhibits the most variance. The purpose of the report is to determine any microstructural differences within the region of interest in the part. When microstructures of the inner section and outer section of the part were looked at it was determined that they exhibited a martensitic structure. There was a noticeable difference in the lath structure between sections. The outer region contained larger more widely spread laths of an average length …


Effects Of Annealing/Solution Treating And Aging On Longitudinal And Transverse Properties Of Ti-6al-4v Forgings, Blake Reller Jun 2012

Effects Of Annealing/Solution Treating And Aging On Longitudinal And Transverse Properties Of Ti-6al-4v Forgings, Blake Reller

Materials Engineering

Forty-eight subsize round-bar tensile samples (ASTM E8) were machined from 3-in-thick forgings of Ti-6Al-4V. Half of these samples were cut so the axis aligned with the longitudinal (LG) direction of the forging, the other half were cut to align with the transverse (LT) direction. Four samples from each direction were subjected to one of six heat treatments so that a total of eight samples received each treatment. Annealed samples were held at 1350°F for two hours, then air cooled. Solution treated and aged (STA) samples were solution treated at one of five temperatures between 1785°F and 1435°F for one hour …


Analyzing The Corrosion Resistance Of Ni-Shield 200 Coatings At Different Temperatures When Exposed To Sulphuric Acid, Alex Hussinger Jun 2012

Analyzing The Corrosion Resistance Of Ni-Shield 200 Coatings At Different Temperatures When Exposed To Sulphuric Acid, Alex Hussinger

Materials Engineering

Six steel samples each were twin wire arc sprayed with Hastelloy C-276 or Nickel-Shield 200 coatings approximately 0.020″ thick. These samples were then cut into 3″ by 3″ squares. A 2″ diamond grit hole saw was used to abrade and polish to a smooth surface a ring in the middle in order to get an O-ring mechanical seal. The samples were then weighed and loaded into a jig that started from the bottom up with a stainless steel plate, then the sample, then a Viton O-ring, a ¾″ thick glass plate with a 1 3/4″ hole cut in it, another …


Characterization Of Positive Macrosegregation At The Subsurface Of Direct-Chill Cast 7050 Aluminum Forging Billets, Aaron Youril Jun 2012

Characterization Of Positive Macrosegregation At The Subsurface Of Direct-Chill Cast 7050 Aluminum Forging Billets, Aaron Youril

Materials Engineering

Segregation of alloying elements during casting of forging billets may persist to the final forged component leading to unacceptable surface appearance. Determination of the elements or compounds that segregate is the essential first step to solving this problem. Differential Scanning Calorimetry (DSC) was used to determine a composition profile of the macrosegregation occurring at the subsurface of an as-cast 7050 aluminum alloy billet. Data collection was carried out by separating 10 to 20 mg samples from the outer centimeter along the radius of the billet, as well as samples from the bulk interior of the billet for comparison with the …