难加工材料铣削残余应力研究进展

镍基高温合金、钛合金等材料具有良好的高温强度、耐热性和耐腐蚀性等优异性能,已广泛应用于航空航天领域,然而这些材料属于典型的难加工材料,其相对切削加工性能很差,且已加工表面易产生显著残余拉应力,严重影响零部件使用寿命及性能。通过适当的方法调整和控制已加工表面的残余压应力,可以明显提高零件疲劳强度和耐腐蚀性。压应力制造技术是指以获得残余压应力为目标的制造技术,是一种典型的抗疲劳方法。将超声技术与其他加工方法复合实现残余压应力的主动控制,是目前抗疲劳制造技术的主要方法之一。然而,由于受超声加工的临界速度限制,超声与高速复合加工的研究相对较少,但两者均是目前压应力制造领域高度关切的先进加工方法,如果两者能有效复合,必将使核心部件制造在保证更加优良的抗疲劳性能的同时,获取更高的效率。通过分析铣削加工、高速加工以及超声振动加工中残余应力的研究现状,提出可将高速加工和超声振动加工相结合,从而实现难加工材料的高效压应力制造。

Research Progress of Residual Stress in Milling of Difficult-to-machine Materials

Since nickel-base superalloy and titanium alloy feature in good high temperature strength, heat resistance, corrosion resistance and other excellent properties, they have been widely used in the field of aeronautics. However, these were typical difficult-to-machine materials of poor machinability, significant residual tensile stress could be easily generated on the machined surface, seriously affecting service life and performance of parts and components. It could obviously improve fatigue strength and corrosion resistance of the parts by adjusting and controlling the residual compressive stress. Compressive stress manufacturing technology, a typical antifatigue method, refers to a manufacturing technology aming to obtain residual compressive stress. Active control of residual compressive stress by combining ultrasonic technology compound with other processing methods was one of the main methods of antifatigue manufacturing technology. However, due to critical speed limit of ultrasonic machining, a few researches were carried out on ultrasonic and high speed composite manufacturing. However, both of them were the advanced manufacturing methods in compressive stress field. If the two methods could be integrated effectively, production of key parts could achieve higher efficiency while guaranteeing superior antifatigue performance. By the analyzing residual stress research progress of milling, high-speed machining and ultrasonic vibration machining, it was proposed that high speed machining and ultrasonic vibration machining could be combined in order to achieve efficient compressive stress manufacture of difficult-to-machine materials.