by Jack Goho
Gideon Analytical Laboratories received two metal castings. One was a cylinder and the other was an insert to the bottom of the cylinder. Metal means a process, in which liquid metal is poured into a mold, that contains a hollow cavity of the desired shape, and then allowed to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Traditional techniques include lost-wax casting, plaster mold casting and, sand casting. The modern casting process is subdivided into two main categories: expendable and non-expendable casting. There was some form of contamination on the two metal castings that were received, and the goal was to determine what it was.
For failure analysis, SEM-EDS was used to analyze the metallurgy. The spectra gave the elements present at various energy levels. The insert had many voids and embedded contamination on the lip where the lip was exposed to the environment as it was inserted into the cylinder. A cross section of the insert showed an excessive number of voids. SEM-EDS needed to be performed several times because it revealed the surface was contaminated with foreign elements. The cylinder was cut to expose pure metal, and SEM-EDS analysis taken. The SEM-EDS analysis revealed that the voiding was not caused by environmental or application conditions; it was part of the casting conditions and inherent in the metal at inception.
Time and time again, Gideon Analytical Laboratories has successfully helped companies with their failure analysis problems. This case is just one in hundreds of success stories. We have helped companies save time, money, and reputation by accurately diagnosing the causes of their electronic failures. We have the knowledge, the expertise, and the equipment to solve your problems. Whether it be SEM-EDS or FTIR, radiography, moisture ingress testing, passivation integrity testing, ion chromatograph analysis, MLCCs, electrolytic or film capacitors, trust Gideon Analytical Laboratories. From MOSFETs to metallurgy, we get the job done!! Is it a design problem? An application problem? Is it a problem with a manufacturer or a supplier? Find out for sure. Give Gideon Analytical Laboratories a call today.