Abstract: Hardened Mold Steel(HMS) is a sort of typical difficult-to-cut material.With the development of aerospace technology,hardened mold steel is becoming increasingly widespread.Recently,with the application of high power ultrasonic vibration technology and its research progress,ultrasonic machining of hardened materials processing showed unique advantages compared with traditional processing,which has verified by lots of experiments.Focuses on the milling force characteristics during one-dimensional ultrasonic vibration assisted milling of hardened mold steel SKD61 and related experiments were carried out.Research results show that ultrasonic vibration amplitude has obviously influence on milling force,which further proves the advantages of ultrasonic vibration assistance in the machining of hardened materials.Moreover,the influence rules of milling parameters such as rotating speed,feed rate,cutting depth on milling forces were clarified through factor experiments.

Key words: hardened mold steel, ultrasonic assisted milling, cutting force