Since the 70s from the 20th century, the domestic hot diamond drill geological graphite mold, generally used in high-purity graphite brick processing, through continuous selection, development and improvement, the main technical performance parameters can basically meet their pressing sintering process requirements. However, compared with the current international advanced level, there is a large gap, to cite two examples can attest.

(1) Some of our customers are doing a hot forming geological diamond drill bit, made of graphite mold core columns (Figure 1) is easy to sticking with the carcass, burning phenomenon, life is short, only use 3 to 4 times. While imports from Germany or Japan, graphite mold, the above drawbacks becomes very slight, the service life of up to 6 to 8 times.

(2) early in 2009 our customers in Iran, using secondary geological thermoforming production of diamond drill bit inserts, the use of domestic graphite machining graphite mold pressure head (as shown in Figure 2 a), the resistivity is relatively low, only about 8 ~ 11L8m, heating current is large, many metal powder inhalation, life is short, only 5 to 6 times, i.e. oxidation, chipping phenomenon. The use of the German 755 graphite machining graphite mold pressure head, high resistivity, about 13 ~ 15L8m, smaller than the domestic heating current 20 percent, strong antioxidant, oxidation burning slower, life of up to 50 -60 times.