Patent drafters generally define a high-entropy alloy (HEA) as a composition of four or more principal elements in near-equiatomic or specified atomic-percent ranges, distinguishing it from traditional alloys built around one dominant base metal. Medium-entropy and multi-principal-element alloy terminology is used interchangeably in claims, which is why a search string needs to capture all three phrases to be comprehensive. In this dataset, the search combined those title terms with process and property terms like solid solution strengthening, phase stability, arc melting and corrosion resistance to focus on families that go beyond a bare composition claim. Practitioners should expect claim language to specify exact atomic-percent ranges for each element rather than nominal ratios.

C22C, the core alloys classification, appears in nearly the entire corpus (168 of 169 families) and covers composition claims. B22F, powder metallurgy, is the next most common at 59 families and covers powder-based production routes including those feeding additive manufacturing. C22F, non-ferrous metal treatment, and B33Y, additive manufacturing, follow at 41 and 24 families respectively, with smaller counts in coating (C23C), casting (B22D) and welding (B23K). A comprehensive prior-art or freedom-to-operate search in this space should not stop at C22C alone, since processing claims are increasingly filed under these secondary classes.

The trend in this dataset rose from 17 families in 2017 to a peak of 23 in 2024, passing through 13 at the 2022 midpoint, which shows growth but not a steep or steady one. The final one to two years of any patent trend are understated because publication lags filing by roughly 18 months, so the apparent softening in 2025 and 2026 should not be read as a confirmed slowdown yet. Taken together, the honest read is that filing activity has been flat-to-modestly-growing over the tracked period rather than in a clear upward or downward trend.

The dataset shows a fragmented field: recent-year momentum is thin across almost every assignee, with the most active recent filer adding only a single family in the latest tracked year and showing flat year-over-year change. Several previously active assignees, including university and corporate research arms, show zero filings in the most recent period. Co-assignee collaboration is also rare, with only two recurring pairs in the entire corpus, both involving the same automotive filer paired separately with US university research foundations. This points to a field led by activity rather than by a small number of dominant, consolidated programs.

The clearest gap sits between composition and processing: while C22C composition claims cover almost every family in the corpus, additive manufacturing (B33Y, 24 families), coating and surface deposition (C23C, 18), casting (B22D, 10) and welding or joining (B23K, 9) are comparatively thin. That imbalance suggests processing-route claims tied to a specific alloy composition, such as a defined heat-treatment schedule or powder-feedstock specification for a named HEA system, are less contested than a new composition claim on its own. Geographically, India (24 filings), Japan (13) and South Korea (10) receive meaningfully less filing volume than the US and China, which may leave regional coverage gaps for a global filing strategy.