{"id":352,"date":"2022-08-22T08:00:00","date_gmt":"2022-08-22T08:00:00","guid":{"rendered":"https:\/\/www.magnetexpert.com\/blog\/?p=352"},"modified":"2025-01-08T10:06:15","modified_gmt":"2025-01-08T10:06:15","slug":"corrosion-resistance-in-different-permanent-magnets","status":"publish","type":"post","link":"https:\/\/www.magnetexpert.com\/blog\/corrosion-resistance-in-different-permanent-magnets\/","title":{"rendered":"The Truth About Corrosion Resistance In Different Permanent Magnets"},"content":{"rendered":"\n

Every permanent magnet contains a form of iron, iron displays the most dramatic ferromagnetic properties of all elements, which is why it is found in the most powerful magnets. However, iron is highly reactive to water and hence makes magnets with high iron content very susceptible to corrosion.<\/strong><\/p>\n\n\n\n

Other ferromagnetic elements used in different types of permanent magnets include nickel, cobalt, gadolinium, and dysprosium all of which have an impact on both magnetic strength and resistance to corrosion.<\/p>\n\n\n\n

There are a lot of factors to consider when exploring a custom magnetic assembly and corrosion resistance is one of the key factors you just consider, so take a look as we break down how resistant each magnetic material is to corrosion. <\/p>\n\n\n\n

Neodymium Magnets<\/strong><\/h2>\n\n\n\n

The strongest permanent magnets available are neodymium\nmagnets, but because of their high iron content, 64-68%, they are also highly\nsusceptible to corrosion in damp environments.<\/p>\n\n\n\n

Modern manufacturing techniques have seen traces of other\nrare earth elements such as dysprosium added to the NdFeB alloy to improve\nresistance to corrosion as well as other magnetic properties. <\/p>\n\n\n\n

Due to their susceptibility to corrosion neodymium magnets are almost always coated before being used. <\/p>\n\n\n\n

A very common coating used for permanent magnets is a triple layer of nickel-copper-nickel, however, there are many other suitable options including but not limited to gold, silver, zinc, tin, epoxy, PTFE, and various paints and lacquers. <\/p>\n\n\n\n

Samarium Cobalt Magnets<\/strong><\/h2>\n\n\n\n

Samarium cobalt magnets, which like neodymium magnets are\npart of the rare earth family, are much more resistant to corrosion even when\nleft uncoated. This is because much of the iron used in neodymium magnets is\nreplaced with cobalt, which does not react to water. <\/p>\n\n\n\n

You will still find many samarium cobalt magnets coated as standard,\nbut this is essentially for aesthetic purposes or for application-specific\nreasons such as adhesion or sterility. <\/p>\n\n\n\n

Samarium cobalt magnets are widely used in marine and offshore applications when they have to cope with being constantly exposed to saltwater air.<\/p>\n\n\n\n

Alnico Magnets<\/strong><\/h2>\n\n\n\n

Alnico and ferrite magnets are both known for their\nresistance to corrosion, although they don\u2019t provide the same level of magnetic\nperformance as rare earth samarium cobalt and neodymium magnets. <\/p>\n\n\n\n

Some grades of Alnico magnets do contain traces of iron and\ntherefore will display some light surface corrosion over time if exposed to\nwater. However, if exposed to other lubricants such as oil, solvents or alcohol,\nalnico performs very, very well. <\/p>\n\n\n\n

Traditionally, alnico magnets have been coated in red paint; it is not clear how or why this custom started but it is one still followed today with most alnico magnets instantly recognisable by their trademark red finish. <\/p>\n\n\n\n

Ferrite Magnets<\/strong><\/h2>\n\n\n\n

Ferrite magnets, also known as ceramic magnets, are made\nfrom iron oxide, and as a result, they simply do not corrode even when\nsubmerged in water.<\/p>\n\n\n\n

Due to their unrivalled resistance to corrosion, ferrite magnets are very rarely coated, but as ferrite is a dusty material some applications will require some surface treatment to avoid the dust spreading.<\/p>\n\n\n\n

Contact Magnet Expert Today<\/strong><\/h3>\n\n\n\n

At Magnet Expert, we welcome any inquiry about magnets, their applications, and your custom magnet needs. If you have questions regarding our magnetic assemblies or systems, technical information, and advice, or you simply want to place an order please call 0845 519 4701.<\/p>\n\n\n\n

If you prefer to send us an e-mail directly, please feel free by emailing us at sales@magnetexpert.com.<\/p>\n\n\n\n

Our business hours: Monday to Friday 8.00 am to 5.30 pm.<\/p>\n\n\n\n

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<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Every permanent magnet contains a form of iron, iron displays the most dramatic ferromagnetic properties of all elements.<\/p>\n","protected":false},"author":3,"featured_media":948,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[79,2],"tags":[133,170,94,57,171,100],"class_list":["post-352","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-frequently-asked-questions","category-guides","tag-alnico-magnets","tag-corrosion","tag-ferrite","tag-neodymium-magnets","tag-resistance-to-corrosion","tag-samarium-cobalt"],"_links":{"self":[{"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/posts\/352","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/comments?post=352"}],"version-history":[{"count":1,"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/posts\/352\/revisions"}],"predecessor-version":[{"id":955,"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/posts\/352\/revisions\/955"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/media\/948"}],"wp:attachment":[{"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/media?parent=352"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/categories?post=352"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.magnetexpert.com\/blog\/wp-json\/wp\/v2\/tags?post=352"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}