Patent ID: 8323072

Claim:
A method of finishing transparent ceramic armor selected form the group consisting of spinel, sapphire, and aluminum oxynitride, the method comprising the steps of: rough grinding a first surface of the transparent armor; intermediate pre-polish grinding the first surface after rough grinding with a first structured abrasive article comprising: a structured abrasive layer adhered to a first side of a backing, the structured abrasive layer having a plurality of abrasive composites; the plurality of abrasive composites comprising agglomerates and a matrix binder; the agglomerates comprising a glass binder and diamond abrasive particles having an average size of 15 micrometers or less and the agglomerate size is about 40 to about 400 micrometers; and the structured abrasive layer having a bearing area ratio between about 40 percent to about 70 percent; intermediate pre-polish grinding the first surface after pre-polish grinding the first surface with the first structured abrasive article with a second structured abrasive article comprising: a structured abrasive layer adhered to a first side of a backing, the structured abrasive layer having a plurality of abrasive composites; the plurality of abrasive composites comprising agglomerates and a matrix binder; the agglomerates comprising a glass binder and diamond abrasive particles having an average size of 15 micrometers or less and the agglomerates size is about 40 to about 400 micrometers; the structured abrasive layer having a bearing area ratio between about 40 percent to about 70 percent; and wherein the diamond abrasive particles of the second structured abrasive article have a particle size no more than 50% of the size of the diamond abrasive particles in the first structured abrasive article.