Performance and Surface Integrity of Wire Electrical Discharge Machining of Thin Ti6al4v Plate Using Coated and Uncoated Wires

摘要

Wire Electrical Discharge Machining (WEDM) is one of the most important production technologies to manufacture very accurate small components and tools on any electrical conductive material. Titanium and its alloys have been widely used in automobile and aerospace industry as well as in medical engineering field. Small components and tools with complex geometrical shapes are difficult to be produced on titanium alloys by both conventional and nonconventional machining technologies. In this work an experimental investigation on the influences of wire electrode type and electrical variables when WEDM a thin plate of Ti6Al4V alloy has been carried out. Uncoated brass wire and copper wire with a diffused zinc coating were used for the experiments. Interval time, wire run-off speed, discharge duration and dielectric inlet pressure were evaluated in order to achieve adequate process parameter settings. Characteristics of surface integrity were also investigated. The best technological results for all tested WEDM parameters were attained for copper wire with a diffused zinc coating. The recast layer of the samples WEDMachined with the copper wire presented a smaller thickness and more compact than that obtained with uncoated brass wire. For WEDM with both types of wire, the existence of thermal cracks was observed.