Glass Expert Discusses Visibility of NiS Particles

Tempered glass failure analysis is mainly difficult because the panel disintegrates into a very large number of semi identical particles; therefore, the failure origin is impossible to locate. In several cases Read Consulting has had the opportunity to examine several failed (caused by Nickel Sulfide, NiS, particles) tempered glass panels that have remained intact. In some cases the windows were laminated; in the others, the windows remained verticle and stayed interlocked. Once the origin is located and preserved, an eyeloop or low power microscope is all that is required to see the NiS particle. The upper left photograph is a macrophotograph of an inplace failed laminated window. In this case the NiS particle is visible to the naked eye. It is a sphericle particle on the fracture surface. Upper right is an 8X photo-micrograph of the particle after the window has been taken apart. This root cause failure analysis does not require scanning electron microscope. This type of tempered glass fracture analysis merely needs an intact failed window.