gambit
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I believe that China have managed to develop engines that match or exceed reliability of Russian AL-31F engine. This engine have MTBO of 1000 hours. This is good enough for requirements for PAF because it does NOT have GLOBAL operational commitments. PAF is limited to defense of the country.
But American? American companies have managed to develop some engines that have MTBO of 6000 hours by now. Such is the disparity between US and Russia lately.
Each Blade a Single Crystal
Clever casting techniques produce jet engines that can withstand 2,000-degree temperatures, allowing unprecedented efficiency.
www.americanscientist.org
In jet engine use, single-crystal turbine airfoils have proven to have as much as nine times more relative life in terms of creep strength and thermal fatigue resistance, and over three times more relative life for corrosion resistance, when compared to small-grained crystal counterparts. Modern high-temperature turbine jet engines with long life (that is, on the order of 25,000 hours of operation between overhauls) would not be possible without the use of single-crystal turbine airfoils. By eliminating grain boundaries, single-crystal airfoils have longer thermal and fatigue life, are more corrosion resistant, can be cast with thinner walls—meaning less material and less weight—and have a higher melting point temperature. These improvements all contribute to higher gas turbine thermal efficiencies.
This does not mean the F119 (F-22) and F135 (F-35) can fly for 25K hrs. It means that the LIKELIHOOD of core engine failures due to turbine blade weakening is low, making the overall engine better at field maintenance. The longer the engine can stay in the field instead of depot, the more capable the engine for deployment in terms of geography and duration. Look at any jet engine, the bulk of FIELD maintenance is on all the peripheral doo-dads attached around the casing. DEPOT maintenance is breaking into the core and we do not want that. Going into the core is time consuming, costly, and requiring nearly cleanroom environment.