Abstract: In respect to metal-bonded ball-headed diamond wheel with small diameter used in ultra-precision grinding for deep concave non-spherical curved surface part and hemispherical resonator, a precision dressing method based on electrical discharge machining principle is put forward. The effects of mechanical errors and dressing parameters on the profile accuracy of dressed wheel are theoretically analyzed. A ball-headed diamond wheel dressing device is designed and built on the basis of the analysis results. The influence of dressing parameters on the profile accuracy of dressed wheel is investigated by orthogonal experiments, then the optimal electrical discharge parameter is obtained. The experimental results show that the dressed wheel’s profile accuracy is superior to 0.8 μm with good effect of abrasive protrusion, thus meeting the requirement of wheel dressing in ultra-precision grinding of hemispherical resonator and other optical parts.

Key words: Dressing parameter, Electrical discharge dressing, Metal-bonded diamond wheel, Profile accuracy, Small diameter ball head