It is heavily concentrated at the top: one assignee holds 21 of the 29 records in the ranked set, while the fifth-ranked filer holds only 1. The ranking itself covers just 6 companies, so this is a narrow field rather than a broad competitive landscape. A new entrant should assume the dominant filer’s specific mechanisms — distortion mitigation in directed energy deposition and powder-bed re-coater heat management — are already claimed, and plan a design-around rather than a head-on filing.

Filing peaked at 10 records in 2020, and the most recent span that can be treated as complete shows a decline from 10 records in 2021 to 6 in 2024, a 40% drop. Filings from 2025 onward are still incomplete because publication typically lags filing by around 18 months, so it is too early to call this a permanent slowdown. The honest read is a pull-back from a 2020 peak, not a confirmed exit from the field.

US20210154771A1 covers a powder bed fusion re-coater with an integrated heat source that pre-heats each deposited powder layer during leveling and can reheat the bed after selective laser or beam fusing, aimed at reducing cracks and dimensional flaws from thermal gradients. It is cited 9 times in this dataset and was filed by Divergent Technologies, Inc. Anyone building a re-coater with in-line pre-heating or post-fusion reheating should review its claims closely for overlap; alternatives that manage stress via alloy composition or post-process treatment rather than in-line re-coater heating sit further from this claim’s core.