Study on the influence of process parameters on the performance of power-mixed neary-dry EDM enhanced TC4 reinforcement layer

The electric spark deposition method was used to strengthen TC4 alloy surface under power-mixed neary-dry EDM. Through the medium mixed with B4C power, graphite electrode as the tool electrode, the effects of peak current, pulse width and pulse clearance on the microstructure and hardness of the reinforced layer surface were studied. The results show that the enhanced layer surface can form a layer of chrysanthemum petal-like layered reinforcing tissue, and the edge of tissue is bright white. With the peak current and pulse gap increasing, the petal-like tissue gradually grows; the hardness of the strengthening layer is increased by about 2.5 times from the 392 HV before strengthening. When the peak current is 6.6∼8.2 A, the pulse width is 60∼100 μs, and the pulse gap is in the range of 80∼100 μs, the morphology and hardness of the strengthened layer are relatively better.