摘要:
It is disclosed a method for fabricating, modifying or repairing of single crystal or directionally solidified articles. Two single crystal or directionally solidified prefabricated parts are joint by isothermally brazing using a brazing material. After that an epitaxial or non-epitaxial layer on the surface of the created article and of the braze joint is applied using a laser metal forming process.
摘要:
It is disclosed a method of applying a coating (12) with a controlled laser metal forming process. A light source with a specific power and a signal capturing apparatus is moved over an article (1) to form locally a melt pool (7) on the surface (5) of the article (1) to which a coating powder (8) is injected. An optical signal (13) is captured from the melt pool (7), and the monitored optical signal (13) is used for the determination of the temperature and temperature fluctuations of the melt pool (7). Furthermore, a control system (16) is used to adjust at least one process parameter such as the power of the light source to obtain desired melt pool properties. Subsequently the melt pool (7) solidifies. The high degree of control over the microstructure provides an efficient tool for generating laser metal formed hard coatings (12) with optimised wear properties.
摘要:
It is disclosed a method of applying a coating (12) with a controlled laser metal forming process. A light source with a specific power and a signal capturing apparatus is moved over an article (1) to form locally a melt pool (7) on the surface (5) of the article (1) to which a coating powder (8) is injected. An optical signal (13) is captured from the melt pool (7), and the monitored optical signal (13) is used for the determination of the temperature and temperature fluctuations of the melt pool (7). Furthermore, a control system (16) is used to adjust at least one process parameter such as the power of the light source to obtain desired melt pool properties. Subsequently the melt pool (7) solidifies. The high degree of control over the microstructure provides an efficient tool for generating laser metal formed hard coatings (12) with optimised wear properties.
摘要:
A leaf seal for sealing a shaft rotating about an axis, in particular in a gas turbine, includes a plurality of spaced-apart leaves arranged in a concentric circle around the axis and fixed in position by brazing, the leaves having surfaces oriented essentially parallel to the axis. The leaves are brazed to one another via intermediate spacers made of a brazing foil, so that a brazed joint is produced by brazing alloy from the brazing foils. The brazing temperature may be set to an optimum value just above the solidus temperature of the brazing foil, at which partial melting of the brazing foil occurs and penetration of liquid brazing alloy into the gap between the leaves is avoided.
摘要:
A leaf seal for sealing a shaft rotating about an axis, in particular in a gas turbine, includes a plurality of spaced-apart leaves arranged in a concentric circle around the axis and fixed in position by brazing, the leaves having surfaces oriented essentially parallel to the axis. The leaves are brazed to one another via intermediate spacers made of a brazing foil, so that a brazed joint is produced by brazing alloy from the brazing foils. The brazing temperature may be set to an optimum value just above the solidus temperature of the brazing foil, at which partial melting of the brazing foil occurs and penetration of liquid brazing alloy into the gap between the leaves is avoided.
摘要:
A gas turbine component consists of a superalloy base material with a single crystal structure and a protective MCrAlY-coating. The MCrAlY-coating the MCrAlY has a γ/β-phase and single crystal structure, which is epitaxial with the base material.
摘要:
A turbine blade for a turbine rotor, is provided having a single-crystal basic body which has a blade tip and extends in the radial direction. The turbine blade includes at least one oxidation-resistant intermediate coating, which is applied by laser metal forming and is epitaxially bonded to the basic body, is arranged on the radially outer blade tip, and in that an at least single-layer, wear-resistant and oxidation-resistant coating, which is applied by laser metal forming and consists of oxidation-resistant binder material and abrasive particles embedded therein, is arranged on at least certain regions of said epitaxial intermediate coating.
摘要:
A gas turbine component consists of a superalloy base material with a single crystal structure and a protective MCrAlY-coating (6). The MCrAlY-coating (6) has a g/g′ single crystal structure, which is epitaxial with the base material. It has be determined the critical factors for the successful epitaxial and crack-free growth of the MCrAlY-coating (6).
摘要:
A gas turbine engine hot gas component repair method for defects that do not extend through the thickness of the component is provided. First defects are removed by machining a cavity in the surface of a component. Coupons, fittable within the cavities are manufactured, are for example coated with brazing medium on an inner surface and then joined to the component by joining means such as laser metal forming. The joint holds the coupon during later heat treatment, thereby eliminating a need for holding aids. Before heat treatment, a further brazing medium can be applied to the surface of the coupon overlapping onto the component. A single heat treatment, brazing the coupon to the component and, brazing the brazing medium to the outer surface of the coupon can, then be used to complete the repair.
摘要:
A gas turbine engine hot gas component repair method for defects that do not extend through the thickness of the component is provided. First defects are removed by machining a cavity in the surface of a component. Coupons, fittable within the cavities are manufactured, are for example coated with brazing medium on an inner surface and then joined to the component by joining means such as laser metal forming. The joint holds the coupon during later heat treatment, thereby eliminating a need for holding aids. Before heat treatment, a further brazing medium can be applied to the surface of the coupon overlapping onto the component. A single heat treatment, brazing the coupon to the component and, brazing the brazing medium to the outer surface of the coupon can, then be used to complete the repair.