Aluminum-Lithium Alloy Patents: Who Leads, Where Gaps Are 2026
- Filing activity has flattened since a 2018 peak of four families a year and sits at or below that pace through the most recent full years, suggesting the core chemistry claims were staked out early and few new entrants are pushing fresh filings.
- Heat-treatment claims (C22F) sit inside 64 of 103 families alongside the base alloy composition class (C22C, 95 families), showing that corrosion resistance in this system is claimed almost entirely through post-processing rather than novel alloy chemistry alone.
- Europe and the US together receive more filings than China (32 and 19 versus 18), with Canada and WIPO PCT routes adding a further 17 between them — a filing geography still anchored in the alloy's traditional aerospace-materials base.
Filing growth compares 2021 (2 records) with 2024 (0) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 103 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This dataset tracks patent families where aluminum-lithium (Al-Li) alloy claims intersect with corrosion resistance, stress corrosion cracking, exfoliation resistance or anti-corrosion treatment, filtered to the alloy composition and metal-treatment IPC classes (C22C21/00, C23F11, C22F1/057). It spans 103 published families filed between 2015 and the 2026 cut-off, giving a compact but technically dense view of a field defined less by new alloy chemistries than by how existing Al-Li systems are aged and treated to resist environmental attack.
Because publication lags filing by roughly 18 months, the last one to two years in the trend chart will read lower than actual filing activity — treat the most recent bars as provisional, not as a real decline on their own.
Filing trends and technology composition
Two views of the same 103 families: when they were filed, and which parts of the metallurgical claim space they occupy.
A flat-to-declining filing curve
Filings rose to a peak of four families in 2018, then settled back toward the two-family level seen at the 2022 midpoint. There is no sustained upward trend in this window — this looks like a mature claim space being maintained rather than a technology in an active land grab.
Treatment classes dominate over new compositions
C22C (alloys) and C22F (non-ferrous metal treatment) together account for the large majority of records, with casting (B22D) and heat treatment (C21D) as secondary supporting classes. The presence of F24S (solar heat collectors) among the IPC hits is a reminder that Al-Li corrosion claims occasionally surface in unrelated end-use contexts, not that solar hardware is a real front in this landscape.
Shares are the percentage of the 103 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Aluminum-Lithium Alloy Corrosion Resistance with Eureka
This page is one run against one query. Ask Eureka your own question about aluminum-lithium alloy corrosion resistance and every answer comes back with the patent numbers behind it.
Try EurekaThe documents this field cites back to
US4532106A — Mechanically alloyed dispersion strengthened aluminum-lithium alloy
A dispersion-strengthened aluminum-base alloy system is provided which is prepared by mechanical alloying and is characterized by high strength, high elastic modulus, low density and high corrosion resistance. The alloy system is comprised, by weight, of at least above 1.5% up to about 3% Li, about 0.4% up to about 1.5% O, about 0.25% up to about 1.2% C, and the balance essentially Al.Filed by INCO Alloys International in 1985, this record predates the dataset window but anchors the mechanical-alloying route that later corrosion-resistance claims build on or design around.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5198045A | Low density high strength Al-Li alloy | 109 |
| 2 | US4816087A | Process for producing duplex mode recrystallized high strength aluminum-lithium alloy products with high frac… | 75 |
| 3 | US4861391A | Aluminum alloy two-step aging method and article | 56 |
| 4 | CN106521270A | 一种改善铝锂合金耐腐蚀性能的热处理工艺 | 49 |
| 5 | US5389165A | Low density, high strength Al-Li alloy having high toughness at elevated temperatures | 45 |
| 6 | WO1998033947A1 | Method of improving fracture toughness in aluminum-lithium alloys | 31 |
| 7 | US4795502A | Aluminum-lithium alloy products and method of making the same | 29 |
| 8 | US4603029A | Aluminum-lithium alloy | 27 |
| 9 | JP1986023751A | Manufacture of al-li alloy having superior ductility and toughness | 21 |
| 10 | US4532106A | Mechanically alloyed dispersion strengthened aluminum-lithium alloy | 21 |
Citation counts favour older, foundational filings inside a searched corpus — read them as markers of influence on later claim drafting, not as evidence of current commercial relevance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for a filing decision
Three read-outs from the trend and citation data that matter more than the raw counts on their own.
The land grab already happened
A peak of four families in 2018 followed by a flattening to two by 2022 indicates the core composition-and-treatment claim space was staked out in the last decade. New filers now compete for narrower process refinements rather than broad alloy or treatment claims.
Corrosion resistance is won on aging, not chemistry
The concentration in C22F alongside C22C shows corrosion performance in this system is predominantly claimed through aging and heat-treatment steps applied to known Al-Li compositions, not through novel base alloys.
Foundational patents still shape drafting
The most-cited records date to the late 1980s and early 1990s low-density, high-strength Al-Li families. Their persistence at the top of the citation table means examiners and drafters still measure new claims against that early art, even decades on.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to aluminum-lithium alloy corrosion resistance, with the prior art for and against each one.
Who holds the claim space
Filing activity concentrates among a small group of legacy aerospace-materials producers, with co-filing pairs pointing to long-running institutional partnerships rather than active joint ventures.
No one is currently pushing new filings
Every major assignee in the recent-momentum data — from legacy aluminium producers to aerospace primes — shows zero filings in the latest tracked year, consistent with the flat-to-declining trend and the 18-month publication lag.
Institutional pairs, not active alliances
Co-assignment is rare and concentrated in a handful of pairs, the strongest linking two legacy metals and aerospace-materials entities across four shared families — a historical partnership footprint rather than a live joint-development signal.
A Western-anchored filing geography
Europe and the United States together outpace China as receiving offices, with Canada and WIPO PCT filings adding further weight to a jurisdiction mix rooted in the alloy's traditional aerospace and rolled-products supply base.
| Assignee | Recent year | YoY |
|---|---|---|
| Reynolds Metals Company | 0 | — |
| Kaiser Aluminum & Chemical Corporation | 0 | — |
| Alcoa Inc. | 0 | — |
| The Boeing Company | 0 | — |
| PECHINEY ROLLED PRODUCTS LLC | 0 | — |
| Alcoa Inc. | 0 | — |
| Martin Marietta Corporation | 0 | — |
| Shanghai Jiao Tong University | 0 | — |
Where to take this analysis
The dataset points to a mature, treatment-heavy claim space with a Western filing base and little recent movement — three directions worth following up.
Map the aging-process sub-claims in detail
With C22F carrying nearly two-thirds of the corpus, a finer breakdown of two-step aging, retrogression and re-aging, and T8-type temper claims would show exactly which process windows are already crowded.
Explore the technology tree in EurekaTrack whether Chinese filers narrow the gap
China trails Europe and the US as a receiving office today; watching whether recent domestic filings (including institutional players such as Shanghai Jiao Tong University) shift that balance is worth a standing search.
Set up a monitoring search in EurekaStress-test designs against the top-cited art
Because the highest-cited records date to the late 1980s and early 1990s, any new composition or treatment claim should be checked against that foundational set before drafting.
Run a freedom-to-operate check in EurekaCommon questions on Al-Li corrosion patents
Lithium additions lower density and raise strength and stiffness, which is why Al-Li systems are attractive for aerospace structures, but lithium-rich grain boundary phases can make the alloy more susceptible to localized corrosion, exfoliation and stress corrosion cracking than conventional aluminium alloys. Manufacturers address this primarily through aging and heat-treatment steps rather than changing the base composition. That is why the patent data in this field concentrates so heavily in metal-treatment IPC classes rather than alloy-composition classes alone.
Filing activity concentrates among a small group of legacy aluminium producers and aerospace manufacturers that have worked with Al-Li systems since the 1980s and 1990s. The recent-year momentum data shows none of these assignees filing new families in the latest tracked year, which is consistent with a claim space that was substantially staked out earlier and is now being maintained rather than expanded. Co-assignment between pairs of these entities appears in only a handful of families, reflecting historical institutional partnerships rather than active joint development.
Based on the tracked window, filings peaked at four families in 2018 and had fallen back to roughly two by the 2022 midpoint, with no renewed upward trend visible through the most recent full years. Because publication lags filing by around 18 months, the very latest year in any such dataset will always look artificially low, so a single down year should not be read as a definitive collapse. Taken together with flat recent-assignee momentum, though, the broader pattern points to a mature rather than an expanding claim space.
The technology composition data shows heavy concentration in base alloy composition and general heat treatment, with much thinner coverage in specific process windows such as combined fatigue and stress-corrosion loading, thick-plate exfoliation behaviour, and surface conversion coatings formulated for lithium-bearing alloys. These narrower branches sit adjacent to the dense core claims but are not saturated by them. A freedom-to-operate review focused on these specific sub-areas is more likely to surface open claim space than a broad composition search.
US4532106A, assigned to INCO Alloys International, claims a mechanically-alloyed, dispersion-strengthened Al-Li system defined by specific weight-percent ranges of lithium, oxygen and carbon, produced by a defined mechanical alloying process. It predates the current dataset window but is a foundational reference point: any new filing built on mechanical alloying of Al-Li systems within similar compositional ranges needs to be checked against it. Because the patent is old, its enforceability window has likely passed, but its claim language still shapes how later applications are drafted to distinguish their compositions or processing routes.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.