A. Dodd, GSI Lumonics, Northville, MI; J. Bialach, Liburdi Automation Inc, Dundas, ON, Canada
Modern gas turbine components, such as blades and vanes, are subjected to some of the most severe operating conditions imaginable. They are continually exposed to thermal, corrosive, abrasive, and other damaging influences. As a result, these parts need to be periodically replaced or repaired to avoid loss of engine power, efficiency and eventual breakdown. Due to high manufacturing costs of these highly engineered components, repair is usually the preferred solution.
The repair process typically requires that the damaged portion of the blade surface be removed using a machining or grinding process. The missing material is then replaced with a suitable filler metal. Typically this is a nickel or titanium alloy selected to match the substrate or to achieve specific properties.
The material replacement is conventionally performed in one of two ways. The first method involves an arc process such as GTAW or PAW and a filler wire. The second method involves a LASER and powder metal. Although these processes are suitable for material deposition, they each have certain limitations. These include excessive heat input, distortion, high porosity levels and material deposition inefficiency.
The LASER AND WIRE process combines the best features of the conventional methods resulting in welds characterized by low defect levels and "near-net" geometry. When incorporated into a fully automated system, with complete control and synchronization of all process parameters, it enables repair of complex components, such as impellers, with unmatched speed, precision and weld quality.
Modern gas turbine components, such as blades and vanes, are subjected to some of the most severe operating conditions imaginable. They are continually exposed to thermal, corrosive, abrasive, and other damaging influences. As a result, these parts need to be periodically replaced or repaired to avoid loss of engine power, efficiency and eventual breakdown. Due to high manufacturing costs of these highly engineered components, repair is usually the preferred solution.
The repair process typically requires that the damaged portion of the blade surface be removed using a machining or grinding process. The missing material is then replaced with a suitable filler metal. Typically this is a nickel or titanium alloy selected to match the substrate or to achieve specific properties.
The material replacement is conventionally performed in one of two ways. The first method involves an arc process such as GTAW or PAW and a filler wire. The second method involves a LASER and powder metal. Although these processes are suitable for material deposition, they each have certain limitations. These include excessive heat input, distortion, high porosity levels and material deposition inefficiency.
The LASER AND WIRE process combines the best features of the conventional methods resulting in welds characterized by low defect levels and "near-net" geometry. When incorporated into a fully automated system, with complete control and synchronization of all process parameters, it enables repair of complex components, such as impellers, with unmatched speed, precision and weld quality.
