Multi-Modal characterization of transparent dome blanks

摘要

A comprehensive suite of NDE/NDI methods has been developed to rapidly inspect transparent ceramic domes for wide range of critical defects in order to identify and mitigate dome manufacturing issues and improve yield through the reduction or elimination thereof. A matrix of hot-pressed (HP), hot isostatically pressed and pressureless sintered (PS) spinel samples with a range of defect types and a variety of surface conditions were inspected using six different, yet complimentary, nondestructive evaluation (NDE) methods. In summary, the combination of three such methods demonstrated the capability to detect all the critical defects with statistical significance for shop floor inspection of spinel domes. The equipment is relatively inexpensive and easy to use, and offers significant payoffs of improved yields and reduced finishing costs by detecting defects prior to the expensive grinding and polishing steps.