Inspection and Image Analysis of Nickel Sulphide Inclusions in Toughened Glass Panels
Nickel sulphide is a kind of detrimental inclusion in toughened glass panels. Once the critical conditions are satisfied, the inclusion will cause the shattering of glass panels. An inspection tool was developed for rapid detection of inclusions. More than one thousand pieces of glass were inspected and seventeen of them were found with inclusions. With the experiment of heat soak, and analysis of dispersive energy spectrum, the appearance of nickel sulfide inclusion was presented, which can be used as guidance of in-line inspection of glass panels. The optical system was improved to get clear image of inclusions inside glass panels. Auto focus technique was used to measure the depth of inclusions, which can provide a parameter for the categorization of inclusions
Nickel sulphide inclusions in glass: an example of microcracking induced by a volumetric expanding phase change
Microcracking about inclusions of nickel sulphide in soda-lime glass has been studied. These cracks are nucleated by the volumetric expansion that accompanies theα-β phase transformation in nickel sulphide. Theα-phase is metastable and, upon transformation to theβ-phase, is accompanied by a volumetric expansion of about 4%. A simple generalized fracture mechanical analysis of the cracking about such inclusions is developed. Firstly, crack initiation about an inclusion is considered; this is then extended to consider inclusions within a thermally tempered plate. The critical dimensions of the inclusion to initiate microcracking in an annealed specimen and to cause spontaneous fracture of a tempered plate are predicted. Observations of nickel sulphide inclusions in annealed and tempered specimens support the predictions. The implications of this work with regard to the addition of fine dispersions of zirconia to ceramics are pointed out.
Calculation of and Errors in the Susceptibility
The measurement of the susceptibility requires three measurements, two of which have to be performed with a substance of known susceptibility. The difference of these last two measurements furnishes the proportionality constant of the apparatus, always employing the same volume, while the difference with the unknown substance gives the required susceptibility.