Manufacturing Of PCD Gun Drill And Experimental Research

PCD gun drills using polycrystalline diamond compact as the blade,can obtain very high precision,great efficiency and long tool life.Polycrystalline diamond is made from diamond powder under the action of Co metal by sintering at high pressure and high temperature[2].It has the characteristics of high hardness,high compressive strength,good wear resistance and thermal conductivity.Although the PCD gun drill has the advantage that the traditional gun drill does not have,but also increases the difficulty of the manufacturing,mainly manifested in two aspects: First,when welding with cemented carbide,the temperature requirements are very strict.Lower temperature can result in insufficient welding strength.Higher temperature is easy to cause thermal damage to PCD.Second,because of the high hardness and brittleness,the removal rate of PCD in the grinding processing is very low,and it can easily cause edge collapse.So it is difficult to guarantee the quality of the cutting edge.The existence of these problems have caused some trouble the tool manufacturers.Due to this,a series of researches have been carried out in this paperOn the basis of consulting a large number of relevant literature,the development and application of PCD super hard cutting tools are summarized,the characteristics of the deep hole drilling process of high silicon aluminum alloy are discussed,and the type of deep hole processing technology,the structure of tools and cutting principle are described in the paper.Based on gun drill basic structure analysis,the NC grinding model is established,and the stress analysis,self-guidance and chip breaking theory are fully discussed in deep hole machining.On the basis of the above,the paper focuses on the principles that should follow when designing PCD gun drills,and the reasonable parameters that should choose in the manufacturing process(cutting,welding,grinding,etc.).Finally,the PCD gun drill production process is improved.In addition,the deep hole drilling experiment of high silicon aluminum alloy was carried out in this paper.Three aspects of the research were studied by changing different parameters.First,changing the cutting speed and feed rate to obtain reasonable cutting parameters of high silicon aluminum alloy;Second,changing the outer blade angle value to optimize theparameters of PCD gun drill;Third,comparing the differences between PCD and carbide gun drill in the deep hole drilling process to analyze the reasons leading to it.