Laser Peening Technology for Remote Processing of Pressure Vessels

2005 ◽  
Author(s):  
Lloyd A. Hackel ◽  
C. Brent Dane ◽  
Jon Rankin ◽  
Fritz Harris
Keyword(s):  
Critical Stress ◽  
High Performance ◽  
Aircraft Engine ◽  
Pressure Vessels ◽  
Metal Alloys ◽  
Complex Geometries ◽  
Laser Peening ◽  
Jet Engines ◽  
Military Aircraft ◽  
Large Pressure

Laser peening technology has matured into a fully qualified production process that is now in routine and reliable use for a broad range of metal alloys. Deep compressive stress developed in metal surfaces extends the fatigue life and stress corrosion cracking life of components, and will enable designers to consider higher stress levels in certain life limited designs. This technology has been applied to critical stress areas of military aircraft engine fan blades and to over 12,000 wide cord fan blades and blade hubs for operation in high performance commercial jet engines. A broad range of materials are in production or development, including but not limited to Ti 6/4 (alpha and beta and BSTOA), 300M and 9310 steels, A1 7050, and A1 2023. Enhancement to the life of components with complex geometries and welds has been demonstrated. The processing capability is being extended with the introduction of a transportable laser peening system including a moveable beam that can go out in the field to treat large pressure vessel systems allowing applications not previously possible.

An Improved Long Life Duration CMC for Jet Aircraft Engine Applications

2002 ◽  
Author(s):  
Eric Bouillon ◽  
Franck Lamouroux ◽  
Laurent Baroumes ◽  
Jean Claude Cavalier ◽  
Patrick Spriet ◽  
...  
Keyword(s):  
High Performance ◽  
Ceramic Matrix Composite ◽  
Chemical Vapor ◽  
Aircraft Engine ◽  
Chemical Vapor Infiltration ◽  
Jet Engines ◽  
Material Development ◽  
Long Duration ◽  
Temperature Capability ◽  
Woven Reinforcement

A new concept of Ceramic Matrix Composite (CMC), mainly based on the use of a self–sealing technology for matrix and the use of a multilayer woven reinforcement, has been developed by Snecma for achieving high performance levels targeted by future jet engines. The driving force for this development has been to increase both lifetime and temperature capability of previous C/SiC and SiC/SiC materials using a monolithic SiC Chemical Vapor Infiltration (CVI) matrix and finishing treatment against oxidation. The first material, which has been developed with this new approach, is CERASEP® A410, using Hi-Nicalon™ fibers from Nippon Carbon. It has been submitted to a comprehensive characterization in order to determine thermo-mechanical properties and to evaluate lifetime duration, using fatigue and creep testing. Further material development is investigating the use of carbon fiber for economical objectives. The combination of such fibers with the new self-sealing matrix is providing promising results for long duration application at high temperature. Such results are permitted by the very high potential of the new matrix.

scholarly journals Towards Damage Controlled Hot Forming

2018 ◽  
Vol 885 ◽  
pp. 56-63
Author(s):  
Markus Bambach ◽  
Irina Sizova ◽  
Aliakbar Emdadi
Keyword(s):  
Metal Forming ◽  
High Performance ◽  
Titanium Aluminides ◽  
Turbine Blades ◽  
Process Time ◽  
Jet Engines ◽  
Internal Damage ◽  
Creep Properties ◽  
Recent Developments ◽  
Ram Speed

Metal forming processes may induce internal damage in the form of voids in the workpiece under unfavorable deformation conditions. Controlling the amount of damage induced by metal forming operations may increase service performance of the produced parts. Damage is crucial in high-performance components of limited workability such as jet engine turbine blades. Recent developments have introduced forged titanium aluminides into commercial jet engines. Titanium aluminides are lightweight intermetallic compounds with excellent creep properties but very limited ductility. Their low workability requires isothermal forging at slow strain rates, which is typically kept constant in the process. This work explores the possibility of increasing the ram speed during the process so that the process time is reduced while the amount of damage introduced into the workpiece is controlled. The results show that a 25% reduction in process time seems viable without increase in damage by solving an optimal control problem, in which the ram speed profile is determined off-line by minimization.

scholarly journals Interplay of structural and dynamical heterogeneity in the nucleation mechanism in Ni

2021 ◽  
Author(s):  
Grisell Díaz Leines ◽  
Angelos Michaelides ◽  
Jutta Rogal
Keyword(s):  
High Performance ◽  
Nucleation Mechanism ◽  
Metal Alloys ◽  
Crystal Nucleation ◽  
Dynamical Heterogeneity ◽  
Fundamental Understanding ◽  
Equilibrium Process ◽  
Non Equilibrium

Gaining fundamental understanding of crystal nucleation processes in metal alloys is crucial for the development and design of high-performance materials with targeted properties. Yet, crystallizationis a complex non-equilibrium process and,...

Analysis of radial roller bearing rating life in complex loading conditions

2021 ◽  
pp. 1-27
Author(s):  
Vladimir Ivannikov ◽  
Mikhail Leontiev ◽  
Sergey Degtyarev ◽  
Valeriy Popov
Keyword(s):  
High Performance ◽  
Roller Bearing ◽  
Complex Loading ◽  
Contact Forces ◽  
Loading Conditions ◽  
Jet Engines ◽  
Inertia Effects ◽  
Internal Contact ◽  
Rolling Elements ◽  
Life Analysis

Abstract An approach for accurate life analysis of radial roller bearings in complex loading conditions is presented. It employs ISO~16281 and accounts not only for external radial loads applied to the inner ring, but also for (i) internal bearing clearance, (ii) flexibility of the bearing rings, (iii) rings out-of-roundness, (iv) inertia effects, (v) rolling elements profile and (vi) rings misalignment. In the last decades these factors have been becoming more and more important for modern high-performance jet engines, whose shafts are commonly hollow and the housing and the rings thicknesses may be of comparable magnitudes. To obtain the distribution of internal contact forces, an advanced static model of a bearing with deformable, potentially misaligned, rings is developed. The bending deformations of the rings are reproduced superimposing deformed shapes from each of the arising internal contact force applied individually. Bearing rollers are allowed to have non-cylindrical profile, its geometry is approximated by means of slices each having constant diameter. A robust numerical scheme for solving the resultant set of equations with the aid of the barrier functions method is constructed. To increase even further the accuracy of rating life analysis, distributions of the contact stresses between the roller and the ring surfaces, obtained by solving numerically the problem of non-Hertzian interaction, are added to computations. A numerical benchmark test is presented to demonstrate the applicability of the developed approach. It shows how the aforementioned factors influence the bearing contact forces and its rating life.

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