New Method for Turbine Blade Internal Cleaning

1995 ◽  
Author(s):  
Jeffrey D. Irvine ◽  
Leonard M. Hampson ◽  
Steven T. Rogers
Keyword(s):  
Hot Spots ◽  
Turbine Blades ◽  
Parent Material ◽  
Wall Material ◽  
Internal Corrosion ◽  
Aluminide Coatings ◽  
Repair Costs ◽  
Part Yield ◽  
New Process ◽  
Process Patent

A program was undertaken to develop an improved internal cleaning procedure for high pressure turbine blades. HP turbine blades, such as JT8D and JT9D 1st stage blades, experience a build up of Si-Ca rich dirt/debris during engine service that inhibits the flow of cooling air creating localized “hot spots”. These “hot spots” lead to accelerated internal corrosion that may cause through-wall material failure. Autoclave processes, utilizing heated, pressurized caustic, are ineffective at removing large amounts of internal debris. A new process, called the TURBO-CLEAN℠ process (patent pending), effectively removes large deposits of internal debris in as few as 2 hours. This process involves pumping heated caustic at pressures approaching 400psi through the internal cavities of turbine blades. The increased caustic flow from this process, compared to autoclave processes, improves cleaning effectiveness. This new process does not harm the parent material or damage protective aluminide coatings. The development of this process has led to reduced repair costs for JT8D 1st blades by improving part yield during repair.

Coating Rejuvenation: New Repair Technology for High Pressure Turbine Blades

2000 ◽  
Author(s):  
Jeffrey A. Conner ◽  
Michael J. Weimer
Keyword(s):  
High Pressure ◽  
Life Cycle ◽  
Wall Thickness ◽  
Life Cycle Cost ◽  
Protective Coatings ◽  
Turbine Blades ◽  
High Pressure Turbine ◽  
Aluminide Coatings ◽  
Patent Applications ◽  
Blade Repair

With the evolution of advanced directionally solidified and single crystal nickel base superalloy turbine blades, managing life cycle costs of high pressure turbine (HPT) blades has become increasingly more difficult. Today’s advanced high pressure turbine blades in aero and aero-derivative turbines feature thin walls (<.030 inches), complex internal geometries, three dimensional (3D) aerodynamic shapes, multiple protective coatings and complex film cooling schemes. A major contributor to blade life cycle cost is the ability to perform multiple repairs without compromising the integrity of these complex components. Repair of HPT blades has traditionally fallen into two categories: mini or partial repairs where blade tips are restored and coated, and full repairs where flowpath coatings are removed, blade tips restored and new coating(s) applied to flowpath surfaces. Historically, the number of full repairs allowed ranges from zero to two based on numerous design considerations, one of which is maintaining a minimum wall thickness. Removal of protective coatings during full repair reduces wall thickness which limits the number of times a full repair can be performed. Furthermore, blades that have sufficient design allowance to permit two full repairs typically have very low yields at the second full repair due to thinning of airfoil walls below minimum thickness limits. The life of a given HPT blade is therefore controlled to a large degree by at what shop visit a full repair is performed. GE Engine Services has developed a new blade repair approach — Coating Rejuvenation — which significantly extends blade life by restoring protective coatings and maintaining wall thickness. Included in the Coating Rejuvenation repair are technologies that allow: removal of physical vapor deposited (PVD) thermal barrier coatings from external surfaces and cooling holes without impacting the bond coat; removal of oxidation and corrosion products from engine exposed coatings without impacting adjacent intact coating; restoration of coating composition to optimize environmental resistance; and upgrade of existing aluminide coatings to platinum aluminide coatings without removal of the existing coating. Combined together, these technologies can be used to support a comprehensive blade repair workscope plan that dramatically increases the life of HPT blades and decreases the life cycle cost for these components. Overviews of these technologies are presented in this paper along with information on how the technology was matured. Due to pending patent applications with the US Patent & Trademark Office as well as pending patent applications in other countries, significant technical detail cannot be presented at this time.

Discharge Coefficients of Holes Angled to the Flow Direction

1994 ◽  
Vol 116 (1) ◽  
pp. 92-96 ◽  
Author(s):  
N. Hay ◽  
S. E. Henshall ◽  
A. Manning
Keyword(s):  
Hot Spots ◽  
Film Cooling ◽  
Discharge Coefficient ◽  
Flow Direction ◽  
Turbine Blades ◽  
Internal Flow ◽  
Design Stage ◽  
Gas Turbine Blades ◽  
Discharge Coefficients ◽  
Film Cooling Holes

In the cooling passages of gas turbine blades, branches are often angled to the direction of the internal flow. This is particularly the case with film cooling holes. Accurate knowledge of the discharge coefficient of such holes at the design stage is vital so that the holes are correctly sized, thus avoiding wastage of coolant and the formation of hot spots on the blade. This paper describes an experimental investigation to determine the discharge coefficient of 30 deg inclined holes with various degrees of inlet radiusing and with the axis of the hole at various orientation angles to the direction of the flow. Results are given for nominal main flow Mach numbers of 0, 0.15, and 0.3. The effects of radiusing, orientation, and crossflow Mach number are quantified in the paper, the general trends are described, and the criteria for optimum performance are identified.

The Influence of Turbine Blade Geometry and Process Parameters on the Structure of Zr Modified Aluminide Coatings Deposited by CVD Method on the ZS6K Nickel Superalloy

2013 ◽  
Vol 197 ◽  
pp. 58-63
Author(s):  
Marek Góral ◽  
Maciej Pytel ◽  
Ryszard Filip ◽  
Jan Sieniawski
Keyword(s):  
Chemical Composition ◽  
Turbine Blade ◽  
Process Parameters ◽  
Aluminide Coating ◽  
Turbine Blades ◽  
Leading Edge ◽  
Nickel Superalloy ◽  
Influence Of Process Parameters ◽  
Aluminide Coatings ◽  
Blade Geometry

The Zr modified aluminide coatings is an alternative concept for replacing Pt-modified aluminide bondcoat for thermal barrier coatings. In the paper the influence of process parameters on the chemical composition and the thickness of aluminide coatings will be presented. The zirconia-doped aluminide coating was deposited on turbine blades made from ZS6K nickel superalloy during the low-activity CVD process. In recent work the influence of turbine blade geometry on thickness of coating was observed. The thickest coating was observed on the trailing and leading edge on the blade cross-section. In the conducted research, the light and scanning electron microscopy were used as well as the EDS chemical composition microanalysis.

New process patent law could create headaches for importers

1989 ◽  
Vol 28 (11) ◽  
pp. 2110
Author(s):  
Daniel B. Moskowitz
Keyword(s):  
Patent Law ◽  
New Process ◽  
Process Patent

The Influence of Deposition Process on Structure of Platinum-Modifed Aluminide Coatings O Ni-Base Superalloy

2011 ◽  
Vol 465 ◽  
pp. 247-250 ◽  
Author(s):  
Lucjan Swadźba ◽  
Ginter Nawrat ◽  
Boguslaw Mendala ◽  
Marek Goral
Keyword(s):  
Protective Coatings ◽  
Base Alloy ◽  
Turbine Blades ◽  
Chemical Vapour ◽  
Base Material ◽  
Deposition Process ◽  
Pack Cementation ◽  
Aluminide Coatings ◽  
Platinum Layer ◽  
Base Superalloy

The modern jet engines used in commercial and military aircrafts are characterized by operating temperature in turbine section above 1000oC. The Ni-base superalloy turbine blades and vanes working in high temperature in very aggressive environment require using of protective coatings. The aluminide coatings are widely used to protect this engine parts. The pack cementation, out of pack and chemical vapour deposition (CVD) technologies are usually used to produce this type of coating. The aluminide coatings can be modified by platinum or other elements. The Pt-modified aluminide coatings are characterized by better oxidation and corrosion resistance in comparison with conventional aluminide coatings and can be used as a bond coat for Thermal Barrier Coatings deposited by EB-PVD technology. In present study the influence of deposition technology and their’s parameters on structure and chemical composition of Pt-aluminide coatings are presented. The base material for coatings was a Inconel 738 Ni-base superalloy. The first step of coatings production were Pt electroplating with different thickness of platinum layer. The second step of coating production was aluminising process. The aluminide coatings were produced by pack cementation and out of pack technologies. Additional the influence of heat treatment of base alloy with coatings was investigated. The structure of all deposited coatings was observed by scanning electron microscopy and the chemical and phase composition of coatings were investigated by EDS and XRD methods. The observed coatings were characterized by two types of structure: first based on NiAlPt phase obtained on thin Pt layer and the second with additional presence of PtAl2 phase on the thick Pt layer.

Numerical Analysis of Diffusion-Controlled Internal Corrosion by the Cellular Automata Approach

2018 ◽  
Vol 383 ◽  
pp. 51-58
Author(s):  
Ulrich Krupp ◽  
Katrin Jahns ◽  
Kamil Balinski ◽  
Jürgen Wübbelmann
Keyword(s):  
Cellular Automata ◽  
Turbine Blades ◽  
Nitrogen Diffusion ◽  
Material Degradation ◽  
Internal Corrosion ◽  
Gas Turbine Blades ◽  
Diffusion Controlled ◽  
Temperature Exposure ◽  
And Diffusion ◽  
Controlled Precipitation

The cellular automata method offers a promising approach to describe diffusion and diffusion-controlled precipitation processes at high temperatures. During high temperature exposure, technical components like gas-turbine blades, furnaces, or exhaust systems, are operating in corrosive atmospheres. The resulting material-degradation processes are diffusion‐controlled, and corrosive species penetrate into the material leading to the formation of embrittling precipitates. Cellular automata (CA) represent distributed dynamical systems whose structure is particularly well suited to determine the temporal evolution of the system. In this study, it is shown that the model is able to consider diffusion, nucleation and growth aspects, interdiffusion between scales, and high diffusivity paths like grain boundaries. This has been demonstrated by applying CA to (i) nitrogen diffusion, (ii) internal intergranular oxidation of nickel-based alloy, and (iii) interdiffusion of a binary diffusion couple.

A Low Temperature CVD Process for Aluminum and Aluminide Coatings

2000 ◽  
Author(s):  
J. Liburdi ◽  
P. Lowden ◽  
V. Moravek
Keyword(s):  
Low Temperature ◽  
Aluminide Coating ◽  
Pure Aluminum ◽  
Turbine Blades ◽  
Chemical Vapour ◽  
Thin Layers ◽  
Internal Diameter ◽  
Temperature Oxidation ◽  
Aluminide Coatings ◽  
Internal Surfaces

A novel, low temperature Organometallic Chemical Vapour process (LOM), developed by Liburdi Engineering is presented in this paper. The process, which is widely used in the electronics industry to apply thin layers of pure aluminum, has been successfully scaled from a 3″ (75 mm) diameter quartz reactor to a production hot wall metal retort with an internal diameter of 18″ (0.45m) and a height of 60″ (1.5m). The capability for simultaneously coating external and internal surfaces is discussed. The aluminum layer can be used directly for low temperature atmospheric corrosion protection in place of IVADIZING or diffusion heat treated to produce an oxidation resistant aluminide coating for superalloys. Results of cyclic oxidation and salt fog corrosion testing are presented. The potential for alloying with modifying elements such as platinum to further enhance its high temperature oxidation resistance and to use the process in conjunction with thermal barrier coatings are presented. Potential applications ranging from coating of heat exchangers and automotive catalytic converters to the coating of industrial and aero turbine blades with complex cooling passages are presented.

Heat Transfer Distribution of Various Rib Geometries for Developing Flow at High Rotation Numbers

2011 ◽  
Author(s):  
Justin A. Lamont ◽  
Srinath V. Ekkad ◽  
Mary Anne Alvin
Keyword(s):  
Heat Transfer ◽  
Hot Spots ◽  
High Performance ◽  
Turbine Blades ◽  
Detailed Knowledge ◽  
Gas Turbine Blades ◽  
Developing Flow ◽  
Rotation Numbers ◽  
Developing Region ◽  
Transient Liquid Crystal Technique

The Coriolis force and centrifugal buoyancy have a significant effect on the cooling performance for rotating internal serpentine coolant channels in gas turbine blades. As coolant flow in rotation is highly complex, detailed knowledge of the heat transfer over a surface will greatly enhance the blade designer’s ability to predict hot spots so coolant may be distributed effectively. The present study uses a novel transient liquid crystal technique to measure heat transfer on a rotating, radially outward coolant channel, which is a simplified model of the actual coolant channels. Various rib types such as 90°, W, and M-shaped ribs of varying types are used to roughen the walls. The present study measures the effects of high rotation numbers (Ro) on the performance and heat transfer distribution of different rib types in developing flow. The present study measures how effective the ribs are up to Ro = 0.5. The Reynolds number (Re) is held constant at 12,000. Results show that in the developing region, the W and M-shaped “high-performance” ribs are just as effective as the simple 90° ribs for increasing heat transfer. The entrance effect in the developing region causes significantly high baseline heat transfer enhancement which may explain why ribs are not as effective as they are in the fully developed region. As the rotation number is increased, results show that the heat transfer on the trailing side increases, while the leading side decreases to a limit and remains constant. For all rotational cases, the W and M-shaped ribs show large changes to the heat transfer distributions on the leading and trailing sides.

Sign in / Sign up

Export Citation Format

Share Document