Experimental Study on Function Electrode Ablation Machining of Difficult-to-Machine Materials.

In order to study the processing adaptability and influencing factors of discharge-induced combustion with function electrode for difficult-to-machine materials, contrast experiments between conventional electric discharge machining (EDM) with cylindrical electrode and combustion machining with function electrode are carried out. Four typical difficult-to-machine materials, i. e. nickel-base superalloy GH4169, die steel Cr12, titanium alloy TC4 and titanium-aluminum alloy TAC-2 are selected in the contrast experiments. The results show that the efficiencies of combustion machining for GH4169 is 112 mm³/min, for Cr12 is 92.28 mm³/min, for TC4 is 347.7 mm³/min and for TAC-2 is 152.5 mm³/ min, which are 37.3, 13.5, 58.7, 13.7 times than those of conventional EDM respectively under the same conditions. With the augmentation of metal activity, the burning intensity and combustion hot melting increase and the combustion effect also becomes more apparent. The characteristics of oxidation layer covering on machining surface plays a significant role in improving alloy material processing efficiency. Some factors determine the relative wear of the electrode, which include the weakened phenomenon on anti-plating of inner ejection liquid, the improvement of ablation processing efficiency, the characteristic of the oxide layer, etc. [ABSTRACT FROM AUTHOR]