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
REVIEW OF PROPERTIES, COMPOSITION AND DEFECTS OF DIFFERENT GLASSES WITH POTENTIAL USE FOR GAS HYDROGEN STORAGE SYSTEMS
The article reviews the research findings available on different types of glasses that presents potential use for high pressure gas hydrogen storage systems. An overview of the mechanical properties of different glasses, the influence of main constituents and the impact of defects to the strength of glass was presented. As part of this research, it can be concluded that the glass gets a significant improvement of tensile strength by reducing its dimensions to fibre sizes or capillaries due to reduced probability of defects presence.
Active profiling and polishing for efficient control of material removal from large precision surfaces with moderate asphericity
We present the development of an active fabrication technology for controlling material removal on large precision surfaces of moderate departure from a sphere. The underlying philosophy was established as an efficient solution to the challenging problem of fabricating secondary mirrors of up to nominally 2.5 m in diameter for modern 8 m class telescopes and beyond. The facility described comprises a CNC profiler, two contact profilometers, and a full size active polisher. The trial work-piece was a convex surface of 830 mm in diameter on a zero-expansion ceramic (`Cervit') blank – a 1/3 scale hyperbolic mirror for a proposed 2.5 m diameter f/7 secondary mirror for the 8 m Gemini telescope. Using software error-correction from profilometric metrology data, a factor of 2 improvement in generating the convex aspheric profile was achieved. An active loose-abrasive polishing process is also described, in which a full-size tool is configured to deliver variable, edgeless, sub-diameter removal-footprints. Real-time monitoring of process variables is described, and approximately 10% convergence in each polishing pass is reported.