Liburdi's Innovative Approach to Gas Turbine Maintenance: LPM® Revealed

Before and after of a repaired gas turbine vane using LPM

Article Summary

  • Liburdi Powder Metallurgy (LPM®) is a metal placement process, not a product, used to repair and strengthen gas turbine components with missing or damaged material.
  • LPM® utilizes a range of superalloy materials for specific applications, particularly for repairing gas turbine components prone to thermo-mechanical fatigue (TMF).
  • LPM® is highly effective at extending the repairable defect size limits, especially for areas difficult to repair by brazing or welding, and it offers design freedom while being a cost-effective alternative to conventional weld repairs. It is exclusively available through Liburdi.

Liburdi Powder Metallurgy (LPM®) is an alternative metal placement process. The key to understanding LPM® is that it is a process and not a product. The LPM® process takes gas turbine components where the material is missing or surface is damaged. LPM® adds or replaces material needed to repair or reconstruct the product and strengthen its integrity. Liburdi's LPM® process can be made of a range of superalloy materials dependent on specific applications.

Cyclic damage to gas turbine nozzles

Liburdi is proficient in exposed gas turbine component repair. Components such as turbine section nozzle guide vanes tend to crack in service due to heat. When gas turbines accelerate, the rush of hot gas expands the airfoils while the endwalls remain cool, resulting in compressive forces causing deformations in the metal. Alternatively, when gas turbines decelerate, the opposite occurs as cool air contracts the airfoils while the endwalls remain expanded.

This cycle when repeated causes slowly growing cracks known as thermo-mechanical fatigue (TMF) in the gas turbine parts. Additional TMF can occur on areas with different areas of thickness causing temperature differentials. This is where Liburdi Powder Metallurgy comes into place.

Multiple images of a Frame 7f vane with Cyclic Damage

LPM® replaces lost metal due to cracking, impact, or corrosion wastage. LPM® can extend 10 times the repairable defect size limits of conventional wide gap processes. LPM® is especially effective at building up surface areas that are normally impossible to repair by brazing and difficult to weld.

Liburdi Powder Metallurgy uses high-strength filler metals employing a highly modified wide gap braze technique. Since the filler is heat-treatable high-strength nickel-based superalloy, it can be adjusted to match the base metal to provide useful mechanical properties.

Multiple images of frame 7f vanes after LPM repair

LPM® allows for innovative design freedom and is a cost-effective alternative to the distortion of conventional gas turbine weld repairs. LPM® is exclusively available through Liburdi. If you're interested in learning more about how Liburdi's LPM® process can help with your turbine component repair, contact Liburdi's IGT Components Repair Manager, Doug Nagy at dnagy@liburdi.com.