New technology improves engine component safety

Commercial air travel is safer than it’s ever been. But mechanical failures can, and still do, occur. Flight UA 328, which left Denver, Colorado on Feb. 20, 2021, suffered a catastrophic engine failure four minutes into the flight. Fortunately, the airplane returned to the airport and landed safely. While the Federal Aviation Administration (FAA) is continually improving safety regulations, there’s more to be done to prevent critical engine failures.

Improvements can be made at the beginning of manufacturing during primary metal processing. Materials must be made to withstand the intense stresses and extreme temperatures components experience, such as turbine disks which hold the turbine blades together while spinning at >10,000rpm and at temperatures up to 1,700°C. Fan blades are also susceptible, as proven with flight UA 328. The National Transportation Safety Board (NTSB) determined the cause was fan blade out failure – two fan blades fractured from metal fatigue, often a result of macroscopic and microscopic discontinuities which can occur during primary metal processing.

Today’s manufacturing processes won’t produce the aircraft engine components of tomorrow. Meeting those standards requires a revolution in parts manufacturing where impeccable processes and precision equipment deliver supreme confidence in the material’s ability to achieve maximum performance.

Ampere Scientific and Consarc Corp. joined forces to apply sensors and software intelligence to revolutionize parts manufacturing. Their current mission is to detect conditions during the vacuum arc remelting (VAR) process that can lead to defects in critical engine components. They’ll use this technology to predict conditions that lead to defects and prevent them from occurring.

VAR furnaces remelt and refine specialty alloys which are formed into critical aeroengine parts in commercial and military aircraft. Current VAR furnaces rely on electrical signals for process control and ingot quality assessment rather than direct evaluation and real-time visualization of the growing ingot.

Ampere Scientific is determined to change that with its VARmetric arc positioning sensing technology that provides a view into the melting process. VARmetric combines advanced electromagnetic field sensing with Consarc’s VAR furnace measurements to capture, record, and display operating characteristics of the furnace not previously detectable during melting. It uses Consarc’s controls to monitor the furnace current, voltage, vacuum level, load cell, ram position/speed, and electromagnetic stirring. VARmetric then integrates measurements of the magnetic fields at a multitude of locations throughout the VAR to image the arc’s location interior to the VAR.

The result is real-time data showing:

• Plots of furnace operational characteristics (current, voltage, vacuum, melt rate, ram speed, etc.)
• Radial arc position overlaid on video images from VAR annulus cameras
• Arc distribution through time
Arc distribution in axial cross-section
• Electrode shape, position as a function of time
• Alarms for side-arc conditions, extended arc gaps, other anomalous events or electrode movements

This data is available to the operator as the ingot is produced and can be used as part of the record of chain-of-custody for any qualified alloy ingot. This information can calculate the probability for solidification defects during operation as part of digital twinning. This gives metal producers, engine original equipment manufacturers (OEMs), and regulatory bodies more confidence that the materials they’re using are produced consistently and can withstand the rigors they are expected to face in extreme environments.

With such guidance, solidification defects will be reduced and confidence in ingot quality will rise. Higher quality ingots yield higher quality components helping the next generation of aircraft fly lighter, faster, stronger, and safer.

Ampere Scientific

Consarc Corp.

About the authors: Paul E. King is president & CEO Ampere Scientific and can be reached at paul@amperescientific.com . Andrew J. Elliott is vice president – technology at Consarc Corp. and can be reached at aelliott@consarc.com.