Magnesium Alloy Coating Patents: Leaders & White Space 2026
- Filing has cooled since 2017. the 2017 peak of 96 filings has not been matched since, and the 2022 midpoint of 73 confirms a flattening rather than a temporary dip.
- China dominates the filing map. 1,010 of the tracked filings went through the Chinese receiving office, more than six times the next-largest office, the United States.
- Electroplating claims run almost as deep as coating claims. C25D (electroplating & electroforming) carries 988 records against C23C's 1,023, showing the two routes are contested about equally.
Filing growth compares 2021 (81 records) with 2024 (93) — 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 1,756 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Magnesium alloys corrode quickly in ambient air and salt environments, which makes surface treatment a precondition for using them anywhere structural — automotive body panels, electronics housings, biomedical implants. This landscape tracks patent families claiming conversion coating, micro-arc oxidation, corrosion-protective coating and general surface treatment on magnesium and wrought magnesium alloy substrates, filtered to the coating and electroplating IPC classes where these claims concentrate. The search spans 2015 to mid-2026, capturing both the post-2017 filing peak and the slower years since.
The dataset draws on 1,756 published patent families. Publication lags filing by roughly 18 months, so the most recent year figures understate actual filing activity; treat the last one to two years as a floor, not a ceiling.
Filing trend and technology composition
Two views of the same 1,756-family dataset: how filing volume moved year over year, and which IPC subclasses carry the claim weight.
A peak in 2017, no return since
Filings ran at 96 in 2017, the high point of the tracked window. The 2022 midpoint sits at 73 — below peak but still substantial — and the count continues down toward 8 in the most recent, still-partial year. This is a flat-to-declining trend, not a technology in an early growth phase.
Coating and electroplating carry the field
C23C (coating & surface deposition) and C25D (electroplating & electroforming) together account for the large majority of records, at 1,023 and 988 respectively. Behind them, C22C (alloys, 160), B05D (coating processes, 144), A61L (sterilising & disinfecting, 136), C23F (corrosion & metal removal, 134), C23G (cleaning of metal surfaces, 103) and B32B (layered products & laminates, 74) mark smaller, more specialised claim territories.
Shares are the percentage of the 1,756 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Magnesium Alloy Coating and Surface with Eureka
This page is one run against one query. Ask Eureka your own question about magnesium alloy coating and surface and every answer comes back with the patent numbers behind it.
Try EurekaRepresentative filing and most-cited prior art
Surface treatment method for magnesium alloy object and structure thereof
The filing combines micro-arc oxidation (MAO) pretreatment with sputtered metal or non-metal layers on top of the MAO layer, with sputtering angle varied according to the MAO layer's own surface roughness, followed by a sputtered paint layer. It is a layered-build approach: oxidation layer first, then optical/functional sputtered layers, then a paint topcoat.Filed by JU TENG INTERNATIONAL HOLDINGS LTD., published 2022-01-13 as US20220010435A1.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5143562A | Broadly applicable phosphate conversion coating composition and process | 74 |
| 2 | EP1857570A2 | Method for forming a nickel-based layered structure on a magnesium alloy substrate, a surface-treated magnesi… | 63 |
| 3 | JP2000345370A | Surface treatment of magnesium or magnesium alloy | 56 |
| 4 | US5683522A | Process for applying a coating to a magnesium alloy product | 52 |
| 5 | CN101871119A | 一种镁合金表面微弧氧化/喷涂复合膜的制备方法 | 49 |
| 6 | US6068938A | Magnesium based alloys article and a method thereof | 48 |
| 7 | WO2003074761A1 | Treating liquid for surface treatment of aluminum or magnesium based metal and method of surface treatment | 46 |
| 8 | US20050067057A1 | Treating liquid for surface treatment of aluminum or magnesium based metal and method of surface treatment | 45 |
| 9 | CN101831652A | 在镁合金表面制备Al-Al2O3复合涂层的方法 | 44 |
| 10 | CN1796613A | 一种耐蚀性镁合金微弧氧化电解液及其微弧氧化方法 | 43 |
Citation counts favour older filings inside a searched corpus — read them as a signal of influence on later filers, not as a ranking of current 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.
Put your own technology through the same analysis
Eureka on the web
When you want the answer in the next five minutes.
The agent works the prompt against patents and technical literature, citing every source.
Run your analysis now →MCP server & REST API
When it has to run inside your own pipeline.
Patent search, landscape analysis and assignee resolution as MCP tools. Drop them into any agent framework, or call REST directly.
Browse MCP servers →What the numbers say about where this field stands
Three readings of the same corpus: filing momentum, geographic concentration, and the split between coating and electroplating claim routes.
Growth already peaked
The 2017 high of 96 filings has not been revisited; the 2022 midpoint of 73 shows a gradual step-down rather than a cliff. Combined with the low most-recent-year count (understated by publication lag), the pattern reads as a mature, consolidating field rather than one still attracting new entrants.
China is the centre of gravity
China's receiving-office share dwarfs Japan (148), the US (126), South Korea (121) and the EPO (111). Any freedom-to-operate check for manufacturing or export into the Chinese market needs to weight this corpus accordingly.
Two routes, near parity
Coating/deposition (C23C) and electroplating/electroforming (C25D) claims run almost neck and neck, meaning neither chemical conversion coating nor electrochemical deposition has a decisive claim-space advantage. New filings will likely keep colliding with prior art in both classes.
Filing is mostly solo, with a few tight pairs
Only 10 co-assignee pairs surface in the dataset, but the strongest — a steelmaker with its own research institute at 20 shared filings — suggests that where collaboration does happen, it is a deep, repeated relationship rather than a one-off joint filing.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to magnesium alloy coating and surface, with the prior art for and against each one.
Who is filing, and where the door is still open
Assignee activity in this corpus is led by Japanese surface-treatment specialists and Korean/Chinese steel and research institutions, with recent-year momentum largely stalled across the tracked leaders.
Even the leader has slowed
Of the assignees tracked for recent-year momentum, only one shows any filing at all in the latest year, and it is a single filing. The rest show zero. This is consistent with the overall flat-to-declining trend rather than a sign any one player has withdrawn specifically.
Steelmaker-institute pairs run deepest
The strongest co-assignee relationship in the dataset pairs a steel manufacturer with its affiliated research institute at 20 shared filings — more than the next two strongest pairs combined, both involving a Japanese surface-treatment chemicals firm working with automakers.
Chinese entities anchor volume
With over half of all filings routed through China's receiving office, Chinese universities, research institutes and industrial assignees make up a large share of the named parties in this corpus, alongside the Japanese and Korean specialists that lead on citation influence.
| Assignee | Recent year | YoY |
|---|---|---|
| Institute of Metal Research, Chinese Academy of Sciences | 1 | — |
| Nihon Parkerizing Co., Ltd. | 0 | — |
| Nisshin Steel Co., Ltd. | 0 | — |
| POSCO | 0 | — |
| Research Institute of Industrial Science & Technology (RIST) | 0 | — |
| Weisike High-Tech Co., Ltd. | 0 | — |
| Northeastern University (China) | 0 | -100% |
| Chongqing University | 0 | — |
Where to take this analysis
The trend and assignee data point to a consolidating field with concentrated claim density in China; the next steps depend on whether the goal is freedom-to-operate, licensing, or identifying a filing gap.
Run a freedom-to-operate check against the top assignees
With filing this concentrated among a small set of Japanese, Korean and Chinese entities, a targeted FTO search against the leading assignees' full portfolios — not just the most-cited records — is the practical next step before committing to a specific coating chemistry.
Explore assignee portfolios in EurekaMap the under-claimed sub-branches in detail
Sub-areas like implant-grade MAO coatings and EV housing corrosion protection show thinner filing density than the core conversion-coating claims. A closer claim-by-claim read of that thinner set can surface where a first claim is still available.
Search white space in EurekaCommon questions about magnesium alloy coating patents
Filing peaked at 96 in 2017 and has trended down since, with the 2022 midpoint at 73 and the latest tracked year far lower. This pattern is typical of a field where the core chemical and electrochemical routes — chromate-free conversion coating, micro-arc oxidation, standard electroplating pretreatments — have already been claimed heavily, leaving less unclaimed ground for new filings. It does not mean commercial demand for magnesium alloy coating has fallen; publication lag also means the most recent one to two years understate true filing activity. Readers should treat the decline as a claim-space signal, not a market-demand signal.
China leads by a wide margin, with 1,010 of the 1,756 tracked filings routed through its receiving office. Japan (148), the United States (126), South Korea (121) and the European Patent Office (111) follow well behind, and WIPO PCT filings account for 47. This concentration reflects where magnesium alloy manufacturing and downstream coating application — automotive, electronics, consumer goods — is heaviest, and it means China-first prior art searches are essential for any FTO work in this space.
Both are surface treatment routes captured in this landscape, but they sit in different technical lineages: conversion coating is a chemical process forming a protective layer through reaction with the substrate, while micro-arc oxidation (MAO) is an electrochemical process using plasma discharge to grow a thicker, harder oxide layer. The IPC data shows coating and deposition claims (C23C, 1,023 records) running close to electroplating and electroforming claims (C25D, 988 records), meaning MAO-adjacent electrochemical routes and chemical conversion coating routes are claimed at roughly comparable density. A new filing needs freedom-to-operate checks against both classes, not just one.
The dataset's assignee ranking is led by a mix of Japanese surface-treatment chemical specialists, Korean steel producers and their affiliated research institutes, and Chinese universities and research institutes. Recent-year momentum has slowed across nearly all of these leaders, with only one showing any filing at all in the latest tracked year. The strongest collaborative relationship in the data is a steelmaker filing jointly with its own research institute, at 20 shared filings — a tighter pattern than the automaker-supplier pairs seen elsewhere in the corpus.
The core conversion coating and micro-arc oxidation claims are densely filed, but adjacent sub-areas carry noticeably thinner coverage: biomedical-grade MAO coatings for implants, sputtered multilayer builds over MAO substrates, corrosion-resistant coatings sized for lightweight EV housings, and laminate integration of coated magnesium sheet under B32B. These sit at the intersection of the core IPC classes and smaller adjacent ones like A61L (sterilising, 136 records) and B32B (layered products, 74 records), where filing density is far lower than in C23C or C25D. A first claim in one of these intersections is more likely to clear prior art cleanly than a claim in the core chemistry.
Research Magnesium Alloy Coating and Surface in depth with Eureka
Go past this page: query the whole magnesium alloy coating and surface corpus yourself, in your own scope.
Every answer comes back with patent numbers you can open.
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.