Experimental study on the effect of electrode materials on the machinability of DC short arc milling Ti2AlNb

Ti2AlNb, as a key material of a new type of aero-engine, has become a difficult material to machine due to its high strength, stiffness and creep resistance. Short electric arc milling (SEAM) is a new and efficient electrical discharge machining method, which is independent of the hardness, strength and toughness of materials, and has become an important method for difficult to machine materials. Taking Ti2AlNb as the experimental object, using tungsten copper and 304 stainless steel as the electrode materials, the processing mechanism of SEAM under different voltage was studied using DC power supply, and the material removal rate (MRR), surface roughness (Sa) and relative tool electrode wear rate (RTWR) of the workpiece were analyzed. In addition, the surface morphology, cross section morphology, element distribution and microhardness of processed Ti2AlNb were also studied. The experimental results show that under 24V voltage, compared with stainless steel electrode, tungsten copper electrode has the highest MRR, the highest is 1981m³/min, the lowest RTWR of the electrode, the relative electrode loss is only 0.82%. The absolute difference of the width of the cross-section of the workpiece is the smallest, and the hardness of the recast layer of the workpiece is close to the hardness of the base metal, which is conducive to further processing.