摘要:
A composition and method for cleaning turbine engine components (10) during servicing. An embodiment of the invention includes a colloidal mixture or slurry (22) of nanoparticles. The slurry may be nontoxic and provide optimal cleaning of tiny surface-exposed crevices (18) of braze joints and components. When a colloidal mixture is in a polar solvent, the pH of the slurry is maintained at about 5 to 9 and at the isoelectric point of the nanoparticles to minimize or prevent agglomeration. When a colloidal mixture is in a nonpolar solvent, the pH of the slurry is maintained at about 5 to 9 and at the isoelectric point of the nanoparticles to minimize or prevent agglomeration by use of surfactant additives.
摘要:
Ni base superalloys containing relatively large amounts of Al and/or Ti are known to be difficult to weld satisfactorily. As the Al and Ti content of the superalloy is increased to improve the strength, the weldability of the component is drastically reduced. It is concluded herein that reducing the γ′ phase improves weldability. A stepwise, controlled heating and cooling process is described to be used in cooperation with a welding process to reduce the γ′ present and thereby improve weldability.
摘要:
A superalloy component, such as gas turbine blade or vane, is structurally welded by placing the component in an isolation chamber. Inert gas is introduced into the chamber. The substrate is welded in the chamber, creating a weld zone. Pressure is applied directly on the weld zone that is greater than atmospheric pressure. Application of such pressure increases the weld zone ductility and reduces likelihood of solidification cracking and strain age cracking, compared to weld zones formed at atmospheric pressure. In some embodiments an isostatic pressure chamber is used to apply isostatic pressure on the weld zone. In other embodiments the welding is performed by laser welding or cladding, TIG welding electron beam welding or autogenous welding.
摘要:
A fatigue resistant turbine through bolt formed from a base material covered by a first surface modification and a second surface modification is disclosed. The first surface modification may be in contact with the base material and, in at least one embodiment, may be a low plasticity burnished layer that increases the residual compressive stresses on an outer surface of the turbine through bolt. The second surface modification may cover the first surface modification and, in at least one embodiment, may be a spinel oxide layer on the low plasticity burnished layer. The second surface modification may be positioned on the first surface modification or on the bare turbine through bolt contact surface without low plastiocity burnishing on the shaft of the turbine through bolt. The first and second surface modifications reduce the likelihood of fretting fatigue failures.