Flash-temperature exceedance events in lubricated rolling and sliding contacts occur onmicrometer–microsecond scales and are implicated in scuffing, tribochemical runaway, andsurface-initiated fatigue. Yet these extreme, intermittent temperature rises remain essentially unmeasured in sealed steel bearings because existing instrumentation senses only bulkthermal states or indirect proxies. This paper documents a three-stage iterative development process for a sensor aimed at directly counting flash-temperature exceedance events inopaque lubricated contacts, and it reports the quantitative failure modes that terminatedtwo successive concepts. The first concept, a pyroelectric-triggered ferroelectric switchinglatch embedded under a wear layer, is eliminated by a geometric dilution factor that suppresses the pyroelectric voltage step by approximately five orders of magnitude relative tocoercive switching requirements. The second concept, the Thermomagnetic Exchange-BiasAvalanche Latch (TEBAL), is physically detectable in free space but is rendered non-viablein steel bearings by threshold broadening, magnetoelastic interference, reset constraints, andmost critically by skin-effect attenuation that prevents microsecond magnetic pulses fromtraversing millimeters of ferromagnetic steel. From these combined failures we argue thatreal-time embedded flash exceedance sensing in conventional steel rolling-element bearingsis infeasible on a five-year horizon, and we propose an Ultra-Wideband Bearing ImpedanceEvent Counter (UBI-EC) and a hybrid inference framework as the practical path forward.
İsmail Hakkı Töremiş (Sat,) studied this question.