Abrasion loading effect

Figure 7.5 Effect of abrasive loading on a-SiC removal rates. Ref [44].

FIGURE 33.12 Effect of carbon black loading on abrasion resistance. 

As is seen from this latter figure, an increase of the solids loading results in a decrease in the cyclone attrition rate. This may be due to a cushioning effect of the increased solids concentration which is well known in comminution processes. This cushioning effect may be interpreted as a decrease in the efficiency T] of the abrasion process. If we assume r] to be a function of jJ and in its simplest form to follow an exponential function,... 

The primary failure modality identified clinically for restorations in posterior teeth is loss of material through abrasion. The complex nature of this failure mode in composite materials makes it difficult to correlate this phenomenon with any one mechanical property. A number of studies have suggested improvements in the system by using various mechanical properties as evidence. These studies have identified major factors such as ceramic filler loading and type of filler [186-191]. Some effects have been identified related to the... 

In the extreme case where the load is supported entirely by solid-solid contact, frictional wear will be at a maximum. However, the transport of slurry under the wafer will be poor, resulting in a limited amount of chemical activity and little lubrication effect. Under such conditions elevated temperatures would be expected and mechanical abrasion would dominate. As a consequence, the polished surface is likely to be severely damaged. 

Chemical-Mechanical Planarization with structured abrasive uses a subpad to manage the pressure variations due to loading over a range of length scales, The effect of subpad construction on pressure responses related to those scales is illustrated. 

For structured abrasive CMP the pressure distribution at the process surface depends largely on the subpad response. That response depends on the length scale of the loading. Contact mechanics and plate bending mechanics have been used to illustrate the nature of the effects of length scale. This understanding is meant to inform experiments to optimize the CMP process for particular situations. 

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