REPAIR AND COATING TECHNOLOGIES FOR NEW GAS TURBINE BLADES

摘要

These components, manufactured by some nickel and cobalt based alloy able to withstand to high temperature and mechanical stresses, have undertook several improvements aimed to increase the overall performances and the useful life i.e. effective cooling systems (impingement cooling, film cooling), advanced metallurgical structure (single crystal, directionally solidified, etc.). To further increase their design life the blades are also covered by protective coating aimed to prevent the surface high temperature corrosion and by thermal barrier coating aimed to decrease the blades skin temperature during operation. Their expected life then depends on the machine operating conditions like: fuel type, load profile, start-stop cycles, environmental conditions, etc.