In this dataset the two terms are used together in search, and most bulk metallic glass (BMG) filings are a subset of the broader metallic glass and amorphous alloy category. Bulk metallic glass specifically refers to amorphous alloys that can be formed in thicknesses of several millimetres or more without crystallising, which is what makes them usable in structural parts like the macroscale gears described in US10941847B2. Composition and processing claims for BMG sit inside the same IPC classes, chiefly C22C, as thinner or ribbon-form amorphous alloys.

The strongest filing cluster in this corpus traces back to California Institute of Technology and named inventor William L. Johnson, whose co-filings with Marios D. Demetriou form the single strongest co-assignee pair identified. Liquidmetal Technologies, working with inventor Atakan Peker, represents the commercial licensing side of that same research lineage. Beyond these anchors, filing volume spreads across a long tail of single- or few-filing entities rather than a second concentrated competitor.

Filings peaked at 70 in 2018 and dropped to 21 by the 2022 midpoint, with every major assignee showing zero filings in the most recent tracked year. Some of this apparent decline is real: composition space under C22C is heavily occupied, which raises the bar for new alloy claims. However, publication typically lags filing by about 18 months, so the most recent one to two years in any trend chart will understate actual filing activity until later records catch up.

The clearest opening is outside core alloy composition (C22C), which carries well over half the corpus, and inside adjacent processing and characterisation branches that are comparatively thin: fracture toughness testing methodology, amorphous alloy laminate interfaces, surface coating deposition onto BMG substrates, and machine-learning-assisted composition design. These branches show real but smaller filing volume, meaning they are active but not saturated the way composition claims are.

US10941847B2, assigned to California Institute of Technology, claims methods for fabricating bulk metallic glass gears above specific thickness and diameter thresholds, tying the composition selection to wear and fracture resistance targets. It does not block all metallic glass gear work outright; it constrains a specific fabrication method and size range, so designs outside those dimensional thresholds or using a different alloy-selection method may sit outside its claims. Any team designing BMG gears at macroscale should read the full claim set against their specific thickness, diameter and alloy-selection approach rather than assume blanket coverage.