中文摘要：

针对光学平面镜面离子束修形工艺中，目前采用的位置加工模式额外加工时间长、精度不高的缺点，提出离子束修形工艺中的速度加工模式，并给出速度加工模式中如何根据驻留时间计算加工中进给速度的方法。使用速度模式在自研的离子束加工机床KDIFS-500上进行了验证试验，对一块直径98mm的微晶玻璃平面样镜进行修形，加工时间为17．5min，样镜经过一次加工后，其面形误差的方均根值由初始的33．2nm提高到了3．1nm，面形收敛比高达10．7。试验结果表明，速度模式加工比位置模式加工可以缩短加工时间，提高加工精度，获得更大的面形收敛比。

英文摘要：

In order to overcome the disadvantages such as more extra process time and lower machining precision in current ion beam figuring process mode, which is referred as position mode, a new process mode is proposed, which is referred as velocity mode. The method to determine the feed velocity in velocity mode is discussed in details. To demonstrate the proposed velocity mode process, a φ 98 flat neoceramic glass sample is figured on the ion beam figuring system KDIFS-500, which is developed by us. Its figure error is improved from initial 33.2 nm root mean square to 3.1 nm root mean square through one figuring process of 17.4 min with convergence ratio reaching 10.7. The figuring result shows that the velocity mode would save process time, improve machining precision and achieve higher convergence ratio than position mode.