Abstract:

Brazing method was introduced into designing and manufacturing diamond drill bit with high matrix to improve its drilling efficiency and extend its life. Firstly, impregnated diamond blocks with good wear resistance were manufactured by hot pressing method. Then new steel body of drill bit including multilayer nozzles and water way was designed, and the welding grooves were formed between two nozzles. Lastly, the impregnated diamond blocks were welded in the drill bit steel body. The life of diamond drill bit manufactured by welding method was improved obviously. Field experimental results showed that the drilling efficiency of two Φ75/54.5 mm high matrix diamond bits was increased by 41.7% and 8.3% respectively, their lives were improved by 50.4% and 32.9% respectively compared with the conventional one. The two times braze welding method takes the advantage of hot pressing method, solves the breaking and blocking off problem of drilling bit, and improves its life greatly.

Key words: high matrix diamond bit, impregnated diamond block, welding method