Combined ZEISS Microscopy for Materials Inspection

A visual inspection suggested that the crack was caused by damage to the surface of the raw part during hardening process. But analysis with the ZEISS Smartzoom 5 digital microscope suggested a different conclusion, says Thomas Schaupp: “Around the central axis, ‘scaling’, i.e. oxidation of the steel, was visible. The fracture therefore originated from the inside.”

A metallographic section was to provide further information. For this purpose, the SPC employees examined the sample with the ZEISS Axio Imager high-resolution wide-field microscope. Thomas Schaupp reports: “The analysis confirmed that 'segregation' had taken place near the central axis, i.e. contamination; in addition, we saw non-metallic inclusions. This caused the steel to become brittle.”

To identify what materials the contamination consisted of, the staff examined a metallographic section from the pinion shaft with the ZEISS EVO scanning electron microscope. The result: there were non-metallic inclusions with high concentrations of manganese and sulfur, as well as segregations of sulfur and phosphorus, in the steel of the pinion shaft near the axle. “Normally, these impurities would still be tolerable,” says Thomas Schaupp, “but a hole was drilled at precisely this point, which put particular strain on the material, and fracture occurred.”

The correlative workflow between light and scanning electron microscopy from ZEISS enabled the SPC materials laboratory to determine this result within a few days. “Our customers need reliable results, and they need them fast,” says Thomas Schaupp. “This is because defects in materials such as steel lead to high costs for our customers.”

For the laboratory manager, there is therefore no alternative to ZEISS: “Hardware and software are optimally matched. Everything works intuitively and easily, as well as quickly and efficiently thanks to the automation functions. This allows reproducible results, regardless of the user. Without ZEISS, our processes would certainly take 30 percent longer.”

In addition, ZEISS offers the cloud-based database ZEISS ZEN Data Storage database, which allows the results of material analyses to be shared with customers – another important efficiency and service factor for Thomas Schaupp. Therefore, nothing is to change in the long partnership, says Thomas Schaupp: “There are short distances to ZEISS in every respect. If we need service, it’s quick, we know each other. And ZEISS understands our needs, why should we change anything?”