Fused grinding materials

Figure 11. Comparison of the grinding performance of known (fused and sol/gel derived) grinding materials on the basis of AI2O3 with a new single phase corundum grit produced by a powder...

SiC, a hard substance(Moh s hardness 9.17), which can be obcained by heating sand and coke. with some sawdust in an electric furnace at high temp. The name carborundum is also applied to other hard materials, such as fused alumina. These materials are used as abrasives for cutting, grinding or polishing(Refs 2,3,5,6 7). 

Fused silica is by far the primary optical material for lens manufacturing. Its mechanical and thermal properties are well known, and its grinding and polishing infrastructure are well established. It is relatively inexpensive and has good index homogeneity over large areas. Lens-grade fused silica, however, is an expensive material. The temperature-dependent properties of fused silica are summarized in Table 13.7. 

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