Experimental Investigation and Analysis in Drilling of Titanium Alloy with Different Coolants

Abstract

The development of aerospace alloys is attaining its attention newlineall over the globe in recent decades. Among the several non-ferrous newlinebased alloys, Titanium alloys are one of the alloy which were newlineextensively employed as structural and intrinsic engineering material. newlineAlthough the alloy has excellent mechanical qualities, its unique newlineproperties of limited heat conductivity and high chemical reactivity newlinemake it a difficult-to-cut alloy. Dry machining of Ti-6Al-4V provides a newlinehigh level of residual tension at the machined area, which is undesirable. newlineThe present investigation deals with the investigation of newlinemachining Ti-6Al-4V alloy under drilling environment. The newlineexperiments were conducted based on the parameters availed using newlineresponse surface methodology under central composite design. The newlineimpact of parameters like cutting speed along with feed rate is studied newlineunder three different cooling environments, namely coconut oil fed newlineunder minimal quantity lubrication, liquid nitrogen and cryogenic CO2. newlineThe torque force generated and the thrust force generated were recorded newlineunder every experimental combinations using the data acquisition newlinesystem coupled with the vertical machining center. Optimization of the newlineparameters was arrived using composite desirability approach and newlinefollowing the confirmation test, the tool wear an unpredictable and newlinemost significant study which need to be carried out was studied by newlineobserving the tip of the carbide tip inserts under scanning electron newlinemicroscope. newlinevii newlineThe results show that the machining under MQL based newlinecoconut oil produced undesirable tool flank wear. The reason shall be newlineattributed to the poor dissipation of the heat as the viscosity of the newlinecoconut oil gets lost due to higher heat generation during the operation. newlineThis results in poor lamination over the machining surfaces. Further newlinewhile considering the liquid nitrogen and cryogenic CO2, the cryogenic newlineCO2 outperforms on the whole exhibiting better tool wear resistance. newlineUnder the optimal machining condition, it is also observed that the newlinetubular