Air Hammer Drill Of Dental Research

In this paper, we analyzed two question that are wearing and fracture of air impulse rotary drill bit teeth in field use. On the one hand from cemented carbide material standpoint, study the effects of teeth wear resistance and impact resistance with different WC grain sizes,and find the better cemented carbide materials which can meet the requirements of the teeth of air percussion-rotary bit. On the other hand make a mechanical analysis on side teeth,research the inclination of side teeth, teeth height as well as the teeth shape's effects on side teeth's peril points stress. Then find reasonable parameters of the side teeth and reduce the chance of side teeth fragmentation. Achieve improving wear resistance and impact resistance and reduce the stress side of teeth through researching cemented carbide materials and analysising mechanical of side teeth. So as to achieve the purpose of improving the service life. The thesis's primary research work is as follows:(1) The scene investigates and studies on air percussion-rotary bit. Through researching literature on the overseas and domestic present status of drill teeth materials(cemented carbide materials), comprehend the cemented carbide characteristics, the development state and the reseach level. On the basis of previous research find cemented carbide teeth materials which can adapt to the requirements of air percussion-rotary bit. Meanwhile make an investigation and analysis on the mechanical of home and abroad bit teeth and provide experience in mechanical analysis of the teeth of this thesis.(2) Failure analysis of air percussion-rotary bit teeth. Include tooth failure modes, failure mechanisms and failure reason analysis. Through the failure analysis of air percussion-rotary bit teeth,understand the failure reasons of drill, failure mechanism and provide a basis for further study.(3) Researching on air percussion-rotary bit tooth materials. Mostly use experimental study means to research the affect of WC's grain size on wear resistance and impact resistance of cemented carbide materials. Use WC powder preparation technique, forming compact sintering technology and subduing growth of WC grain size technology as well as preparatian procedure to product finished teeth after confirming the reasonable WC grain size. Through tooth performance test, microstructure analysis, wear resistance and impact resistance experiments, well develop cemented carbide tooth materials which can meet the requirements of the air percussion-rotary bit.(4) Mechanical analysis of air percussion-rotary bit. Through mechanical analysis of drill tooth in downhole, establish the mechanical model for calculation, identify the suspicious dangerous point within teeth, analyse the relationship between every stress of suspected dangerous points and the tooth height, inclination, radius and tooth form of drill side teeth. Then comfirm more rensonable ones.