Experimental Study On Brazed Sintered Diamond Bits

Multi-layer brazing diamond drill bits are widely used in various industries because of their high drilling efficiency and long service life.The drill bit needs a proper proportional relationship between the wear rate of the carcass and the blade cutting speed during use.In order to achieve the maximum drilling efficiency and longest service life,this article mainly through the "ZHR-15 Q vacuum activated brazing sintering machine",sintering 36 × 20.5-7B / M841,36 × 20.5-11 B / M841,36× 20.5-11W/M841 three kinds of micro drills(hereinafter abbreviated as 7B,11 B,11W).Through the indoor micro drill test,SEM scanning electron microscope and EDS energy spectrum analysis,as well as the hardness,metallographic and friction and wear test of the sample block,to optimize the bit sintering process and formula.The main conclusions of this paper are as follows:(1)Under the micro drill test conditions,the drilling efficiencies of diamond bits7 B and 11 B reached 1.188 m/h and 0.936 m/h,respectively,indicating that the 11 B bit added with WC particles has better wear resistance than 7B bit,but 7B bit Easily bladed,drilling efficiency is higher.(2)SEM and EDS analysis showed that when the brazed sintered diamond drill was magnified 3000 times under scanning electron microscope,the carcass and diamond particles were well combined with no gap;the cutting-edge rate of the drill was 86.736% and 84.046%,respectively.The rates of exfoliate rate were 3.332% and1.304%,respectively.(3)The surface scanning analysis found that there is an enrichment of Cr in the diamond grain boundary or in a certain area,and the chemical and metallurgical bonding between diamond and carcass is realized.(4)Friction and wear test found that the friction coefficient has a process of changing from irregular to regular;due to the presence of WC particles,11 B drill bit matrix has the highest friction coefficient up and down bias value;11W drill bit has lower friction coefficient up and down bias value due to the greater hardness of the carcass.