{"id":8011,"date":"2026-02-26T12:56:42","date_gmt":"2026-02-26T10:56:42","guid":{"rendered":"https:\/\/teceudemo.com\/failure-analysis-starter-key\/"},"modified":"2026-05-21T16:29:28","modified_gmt":"2026-05-21T14:29:28","slug":"failure-analysis-starter-key","status":"publish","type":"post","link":"https:\/\/www.tec-eurolab.com\/en\/failure-analysis-starter-key\/","title":{"rendered":"Failure Analysis | starter key"},"content":{"rendered":"

Failure Analysis on starter key<\/h2>\n

The object<\/h2>\n

An engine start key is a mechanical and\/or electronic device used to start the engine of a vehicle or car<\/strong>. It usually consists of a physical part (the actual key) and an electrical system that interacts with the vehicle.<\/p>\n

In general, inserting the key into the vehicle’s ignition and turning it creates an electrical connection that allows electric current to circulate through the starter circuit. This activates the starter motor, which in turn turns the engine initially so that it starts. Engine starter keys are used primarily on automobiles, motorcycles, and other machines that require an engine to run.<\/p>\n

Starter keys can incur several failure or failure modes:<\/p>\n

    \n
  1. Mechanical wear<\/strong> | The physical key can wear out over time due to repeated use, leading to loss of shape or damage that prevents insertion or rotation.<\/li>\n
  2. Electronic failure <\/strong>| The key’s internal electronic system can fail, preventing proper communication with the vehicle. This can be caused by internal connection problems or broken electronic components.<\/li>\n
  3. Low battery<\/strong> | If the key uses an internal battery to transmit the signal to the vehicle, it may run out over time, preventing proper operation.<\/li>\n
  4. Problems with the ignition<\/strong> | The ignition cylinder, where the key is inserted, may become damaged or worn, making it difficult to insert or turn the key.<\/li>\n
  5. Starter motor problems<\/strong> | The key may be working properly but the engine will not start due to a problem with the starter motor itself…<\/li>\n<\/ol>\n

    To deal with such situations, a specialized mechanic is often needed to repair or replace the key or related components. In addition, some modern cars use keyless start systems (such as push buttons) to reduce the likelihood of failures related to traditional keys.<\/p>\n

    Purpose of the survey<\/h2>\n

    The present investigation aims to analyze the damage that occurred to the supplied starter key.<\/strong> Variousanalyses<\/strong> were carried outto characterize the sample material<\/strong> and verify whether it conformed to the specifications of the technical drawing provided. In addition, an attempt was made to identify how the damage occurred and to hypothesize its possible causes.<\/p>\n

    Information provided by the principal regarding the sample includes:<\/p>\n

      \n
    • It is a copper alloy (CuZn39Pb2 \/ CW612N according to UNI EN 1652) used for semi-finished strips.<\/li>\n
    • The sample should undergo a nickel plating process of the “Cu\/Ni6” type.<\/li>\n<\/ul>\n

      The analyses<\/h2>\n

      The specimen is damaged at about 15 mm from its free end, where a break transverse to the longitudinal axis<\/strong> has occurred. The break shows slight plastic deformation<\/strong> evident. The rupture surface is mainly opaque, but has some bright, plasticized areas around the perimeter. The latter areas are hypothesized to have been crushed after the breakage. Through the use of scanning electron microscope (SEM) and EDS probe, the breakage surfaces were examined.<\/strong> All analyzable areas show equiaxial dimples, which are typical of ruptures that occurred by overloading in ductile mode.<\/strong> The equiaxiality of the dimples suggests that the stress (tension) was mainly axial. The crushed areas confirm their nature; chemical analysis on the failure surface showed that there were no differences between the central and perimeter areas.<\/p>\n

      The detected chemical composition complies with the analytical requirements for a copper alloy for semi-finished strip of designation CuZn39Pb2 \/ CW612N according to UNI EN 1652. Micrographic examination was carried out on a metallographic specimen obtained by sectioning the specimen in question. The purpose was to analyze the microstructure and observe the failure surface in section<\/strong>. The microstructure of the specimen consists of \u03b1 and \u03b2 phases, with a fine and homogeneous dispersion of insolute lead particles. These characteristics are typical of a copper-zinc-lead alloy.<\/p>\n

      The main deformation direction of the microstructure is parallel to the rupture surface, transverse to the key axis. In addition, the rupture surface has a nickel coating with a thickness of 4 \u03bcm. The micrographic evidence of the failure surface is congruent with previous analyses, indicating a plastically corrugated and micro-deformed profile, consistent with a ductile overload failure mode.<\/strong><\/p>\n

      \"\" \"\"<\/p>\n

      \"\"
      <\/figcaption><\/figure>\n

      \"\" \"\"<\/p>\n

      The results<\/h2>\n

      Material characterization analysis confirmedthat the sample consists of a copper alloy CuZn39Pb2 \/ CW612N, in accordance with UNI EN 1652.<\/strong> The microstructure and chemical composition are free of defects and anomalies, and the measured hardness is 166HV. In addition, there is a nickel plating surface coating with a thickness of 4 \u03bcm.<\/p>\n

      Damage analysis revealed that the specimen is broken about 15 mm from its free end. Visual, fractographic, and micrographic analysis indicates that the breakage occurred by overload with a ductile mode, and there are no defects or anomalies in the material.<\/strong> The rolling direction of the strip from which the sample was obtained is parallel to the failure surface, i.e., transverse to the key axis.<\/p>\n

      Conclusions<\/h2>\n

      The specimen material conformed to the requirements, and the rupture was caused by overloading<\/strong>, probably axially, with no material defects or anomalies. It is important to note that, if one were to look for unfavorable factors, one should consider that the rupture occurred transverse to the rolling direction of the starting web.<\/p>\n

      This condition makes the specimen more vulnerable to tensile stresses acting in the axial direction. Since a stress transverse to the rolling direction makes the material’s response more critical, its microscopic structure could adversely affect the effective strength, facilitating failure even under less significant loads.<\/p>\n

      However, no specific information is available on the failure case history or production histories of the sample or similar samples.<\/p>\n

      Is your component damaged? Let’s find out together why<\/h2>\n

      Request information<\/p>\n","protected":false},"excerpt":{"rendered":"

      Failure Analysis on starter key The object An engine start key is a mechanical and\/or electronic device used to start the engine of a vehicle or car. It usually consists of a physical part (the actual key) and an electrical system that interacts with the vehicle. In general, inserting the key into the vehicle’s ignition […]<\/p>\n","protected":false},"author":3,"featured_media":8006,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[57],"tags":[],"class_list":["post-8011","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-how-did-it-break"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/posts\/8011","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/comments?post=8011"}],"version-history":[{"count":2,"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/posts\/8011\/revisions"}],"predecessor-version":[{"id":14038,"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/posts\/8011\/revisions\/14038"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/media\/8006"}],"wp:attachment":[{"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/media?parent=8011"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/categories?post=8011"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tec-eurolab.com\/en\/wp-json\/wp\/v2\/tags?post=8011"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}