<\/p><\/p>\n
\n
| Einflussgr\u00f6\u00dfe<\/td> | Wirkung auf die Mikrorissbildung<\/td><\/tr> |
| Verwendung d\u00fcnner Eloxalschichten, < 5 \u00b5m<\/td> | Gefahr nimmt ab<\/td><\/tr> |
| Hohe Stromdichte (Eloxieren)<\/td> | Gefahr nimmt zu<\/td><\/tr> |
| Geringe Schwefels\u00e4urekonzentration (Eloxieren)<\/td> | Gefahr nimmt zu<\/td><\/tr> |
| Niedrige Badtemperatur (Eloxieren)<\/td> | Gefahr nimmt zu<\/td><\/tr> |
| Einsatz von speziellen Hei\u00dfverdichtungen<\/td> | Gefahr nimmt ab<\/td><\/tr> |
| Nur kaltverdichtet (Nickelfluorid)<\/td> | Gefahr nimmt zu<\/td><\/tr> |
| Einsatz von Kaltverdichtungen (Nickelfluorid) mitHei\u00dfwasser – Alterung<\/td> | Gefahr reduziert sich etwas<\/td><\/tr> |
| Verdichtete Oberfl\u00e4chen in sehr trockenerUmgebungsluft<\/td> | Gefahr nimmt zu<\/td><\/tr> |
| Verdichtete Oberfl\u00e4chen in feuchterUmgebungsluft<\/td> | Gefahr nimmt ab<\/td><\/tr><\/tbody><\/table> <\/p><\/p>\n \n <\/p><\/p>\n","protected":false},"excerpt":{"rendered":" Eloxierte Aluminiumoberfl\u00e4chen zeichnen sich durch ihre sch\u00fctzende, keramik\u00e4hnliche Oxidschicht aus, die jedoch in bestimmten Situationen feine Risse, sogenannte Mikrorisse, aufweisen kann. Diese Mikrorisse werden h\u00e4ufig erst bei schr\u00e4gem Lichteinfall sichtbar, w\u00e4hrend sie bei direkter Betrachtung kaum auffallen. Sie sind ein Indikator f\u00fcr mechanische oder thermische Beanspruchungen der Oberfl\u00e4che und stellen eine typische Form der Sch\u00e4digung […]<\/p>\n","protected":false},"author":10,"featured_media":9224,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","tve_updated_post":" ___TVE_SHORTCODE_RAW__<p><!-- wp:paragraph --><\/p>\n<p>Anodised aluminium surfaces are characterised by their protective, ceramic-like oxide layer, which can, however, show fine cracks, so-called microcracks, in certain situations. These microcracks often only become visible when the light falls at an angle, whereas they are barely noticeable when viewed directly. They are an indicator of mechanical or thermal stresses on the surface and represent a typical form of damage to the oxide layer.<\/p>\n<p><!-- \/wp:paragraph --><\/p>\n<p><!-- wp:heading --><\/p>\n<h2 class=\"wp-block-heading\">Development of microcracks<\/h2>\n<p><!-- \/wp:heading --><\/p>\n<p><!-- wp:paragraph --><\/p>\n<p>An anodised component consists of two different material layers: the soft base material aluminium and the brittle but firmly adhering anodised layer. Stresses between these two layers can cause the brittle top layer to develop fine cracks. These tensions are often caused by temperature differences or mechanical stresses.<br \/>An example of thermally induced cracking is an anodised, dark-coloured aluminium fa\u00e7ade. During the day, it heats up strongly due to solar radiation, while the temperature drops rapidly at night, especially in winter. The resulting temperature changes stress the oxide layer, which can lead to microcracks, even if the layer appears intact on the outside and shows no flaking or splintering.<\/p>\n<p><!-- \/wp:paragraph --><\/p>\n<p><!-- wp:heading --><\/p>\n<h2 class=\"wp-block-heading\">Mechanical and chemical influences<\/h2>\n<p><!-- \/wp:heading --><\/p>\n<p><!-- wp:paragraph --><\/p>\n<p>Microcracks can be caused not only by temperature changes, but also by mechanical stresses such as pressure or bending. The importance of chemical pre-treatment and coating properties is often emphasised in the literature. These factors have a considerable influence on the stability of the anodised layer.<br \/>Sealed and non-sealed anodised layers exhibit different resistance to cracking. While non-sealed anodising layers can withstand temperatures of up to around 150 \u00b0C, sealed anodising layers tend to crack at temperatures of around 80 \u00b0C and above. The type of sealing system used plays a decisive role here.<\/p>\n<p><!-- \/wp:paragraph --><\/p>\n<p><!-- wp:paragraph --><\/p>\n<p><strong>The following conditions can influence the formation of microcracks on anodic layers:<\/strong><\/p>\n<p><!-- \/wp:paragraph --><\/p>\n<p><!-- wp:table --><\/p>\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<tbody>\n<tr>\n<td>Influencing factor<\/td>\n<td>Effect on microcrack formation<\/td>\n<\/tr>\n<tr>\n<td>Using thin anodised layers, < 5 \u00b5m<\/td>\n<td>Risk decreases<\/td>\n<\/tr>\n<tr>\n<td>High current density (anodising)<\/td>\n<td>Risk increases<\/td>\n<\/tr>\n<tr>\n<td>Low sulphuric acid concentration (anodising)<\/td>\n<td>Risk increases<\/td>\n<\/tr>\n<tr>\n<td>Low bath temperature (anodising)<\/td>\n<td>Risk increases<\/td>\n<\/tr>\n<tr>\n<td>Use of special hot sealing processes<\/td>\n<td>Risk decreases<\/td>\n<\/tr>\n<tr>\n<td>Use of cold sealing (nickel fluoride) only<\/td>\n<td>Risk increases<\/td>\n<\/tr>\n<tr>\n<td>Use of cold sealing (nickel fluoride) with hot water<br \/>- ageing<\/td>\n<td>Risk is slightly reduced<\/td>\n<\/tr>\n<tr>\n<td>Sealed surfaces in very dry atmosphere<\/td>\n<td>Risk increases<\/td>\n<\/tr>\n<tr>\n<td>Sealed surfaces in humid atmosphere<\/td>\n<td>Risk decreases<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<p><!-- \/wp:table --><\/p>\n<p><!-- wp:image {\"id\":9226,\"sizeSlug\":\"full\",\"linkDestination\":\"none\"} --><\/p>\n<figure class=\"wp-block-image size-full\"><img class=\"wp-image-9226\" src=\"https:\/\/alufinish.de\/wp-content\/uploads\/2024\/09\/microcracks2.jpg.png\" alt=\"\" \/>\n<figcaption class=\"wp-element-caption\">SEM - picture of a cracked anodised surface<\/figcaption>\n<\/figure>\n<p><!-- \/wp:image --><\/p>__TVE_SHORTCODE_RAW___<\/div><\/div>","tve_custom_css":"@media (min-width: 300px){.tcb-post-list[data-css=\"tve-u-16ecb5f152b\"] .post-wrapper.thrv_wrapper { width: calc(50% - 20px); }.tcb-post-list[data-css=\"tve-u-16ecb5f152b\"] .post-wrapper.thrv_wrapper:nth-child(n+3) { margin-top: 40px !important; }.tcb-post-list[data-css=\"tve-u-16ecb5f152b\"] .post-wrapper.thrv_wrapper:not(:nth-child(n+3)) { margin-top: 0px !important; }.tcb-post-list[data-css=\"tve-u-16ecb5f152b\"] .post-wrapper.thrv_wrapper:not(:nth-child(2n)) { margin-right: 40px !important; }.tcb-post-list[data-css=\"tve-u-16ecb5f152b\"] .post-wrapper.thrv_wrapper:nth-child(2n) { margin-right: 0px !important; }}","tve_user_custom_css":"","tve_globals":{"e":"1","font_cls":[]},"tcb2_ready":1,"tcb_editor_enabled":1,"tve_landing_page":"","_tve_header":"","_tve_footer":""},"categories":[57],"tags":[194,264],"class_list":["post-9233","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-error-patterns","tag-aluminium-2-en","tag-eloxal-2-en","post-wrapper","thrv_wrapper"],"yoast_head":"\n |
![\"\"\/](\"https:\/\/alufinish.de\/wp-content\/uploads\/2024\/09\/microcracks2.jpg.png\")
REM – Aufnahme einer gerissenen Eloxalschicht