Problem

A global leader in aerospace products, aviation instrumentation company in the US, was facing problem in performance of jet engine sensor installed at the exhaust tail of combat aircraft and wanted to review and replace the existing alloy with an alloy that does not demand replacement before certain thousands of hours of use.

Body probes, current design cage code number 97424, conforming to drawings 1608W25 sheets 1 to 8

Application: Aircraft turbine engine sensors parts and electronic components of aviation instrument and control

Evaluation, Assessment, Recommendation And Solution(s)

Present material specified: AMS 5390

Alternate material contemplated: AMS 5754

Recommendation: ACME Nickel Base Super Alloy- AA-X50

Acme Alloy (AA)-X50 is an austenitic nickel-base super alloy containing about 22% chromium for outstanding resistance to oxidation at high temperatures. In addition, the alloy microstructure is niobium (columbium) stabilized which enhances the capability of the cast component (polycrystalline microstructure) to withstand high temperature creep, thermal cycling and thermal fatigue, resulting from variations in exhaust gas combustion temperatures, outperforming the earlier used AMS 5390.

Based on the part geometry of the cast component, and after examining cross-section details of the engine temperature sensor, AA-X50 cast sensor precision machined to drawing was suggested. The alloy is solid solution strengthened, imparts the component exceptional strength at elevated temperatures. Suggested AA-X50 possesses good high temperature stress rupture properties above 1450°F (788°C) and can be used in the end application above 2200°F (1204°) clearly outperforming the present alloy being used in the sensor.

Result

The recommendations and alloy metallurgy provided to the customer were put to good use.However, the details of performance were not shared with us, being national defence security confidential matter and confidentiality agreement signed with AMTEK and subsequently with the Aircraft manufacturer in the US. However, confirmation was given to us for successful performance and replacing with recommended alloy.