Burning crater

When sparks are used for the ablation of electrically conducting solids, less changes with variations in the matrix composition than in the case of arc ablation occur. This is due to the fact that thermal volatilization plays less of a role. However, in the case of brass, it is seen from x-ray analyses of the ablated material on a Nudepore filter, for samples of the crater wall and the burning crater, that zinc volatilizes more than copper (Table 5), which makes the method difficult to apply to these samples. 

---